JP2015228524A - Liquid photosensitive adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a method for manufacturing a semiconductor wafer with an adhesive layer, by which a semiconductor wafer with an adhesive layer sufficiently reduced in voids at a bump portion, and capable of sufficiently reducing warpage after grinding can be obtained; a method for manufacturing a semiconductor device using such a semiconductor wafer with an adhesive layer; and a method for manufacturing a semiconductor wafer with a semiconductor element.SOLUTION: A liquid photosensitive adhesive of the present invention is a liquid photosensitive adhesive for forming a photosensitive adhesive layer on a circuit surface of a semiconductor wafer that has the circuit surface on which a metal bump is formed, and includes (A) a radiation polymerizable compound, (B) a photoinitiator and (C) a thermosetting resin, the (A) component including imide group-containing (meth)acrylate with one carbon-carbon double bond in a molecule.

Description

  The present invention relates to a liquid photosensitive adhesive.

  2. Description of the Related Art As semiconductor devices have become more sophisticated and smaller in size in recent years, flip chip mounting has been performed in which semiconductor elements are mounted on a printed circuit board with a face-down structure. In flip chip mounting, resin sealing is usually performed in the gap between the semiconductor element and the printed circuit board in order to protect the semiconductor element. As a resin sealing method, there are a post-injection method in which a low-viscosity liquid resin is injected after the chip and the substrate are connected, and a pre-supply method in which the chip is mounted after an underfill material is provided on the substrate. Further, regarding the pre-feeding method, there are a method of applying a liquid resin and a method of attaching a film-like resin.

  In the last insertion method, when the gap between the chip and the substrate is narrowed and the pitch is narrowed, it is difficult to fill the liquid resin without generating voids, and it is not suitable for mass production.

  When applying the liquid resin by the first supply method, it is difficult to precisely control the application amount with a dispenser. In particular, when mounting a thin chip in recent years, if the amount applied is too large, the resin that has oozed out during bonding crawls up the side surface of the chip and contaminates the bonding tool. Therefore, in this method, the tool needs to be cleaned, and the process during mass production becomes complicated.

  On the other hand, when using a film-like resin, it is possible to easily give an optimum amount of resin by adjusting the thickness of the film, but on the other hand, a step of attaching a film-like resin called a temporary pressure bonding step to the substrate is required. Usually, in the pre-bonding process, a reel-shaped adhesive tape that is slit to a width larger than the target chip width is prepared, and the adhesive tape on the base material is cut according to the chip size. Thermocompression bonding is performed on the substrate at a temperature that does not react. However, since it is difficult to accurately supply the film to the chip mounting position and it is difficult to process a narrow reel corresponding to a microchip, it is generally pasted by provisional pressure bonding to secure the yield. This can be done by making the film larger than the chip size. Therefore, in this method, it is necessary to provide a margin for the distance from the adjacent parts, and it is difficult to cope with high-density mounting.

  Recently, as one of high-density mounting techniques, a method of producing a semiconductor wafer with an adhesive layer and using a semiconductor element with an adhesive layer obtained from the wafer has been studied. For example, in Patent Document 1 below, a wafer having a film-like adhesive attached thereto is prepared, and after grinding the back surface of the wafer, the wafer is cut together with the adhesive to form chips, whereby the chip size is reduced. There has been proposed a method of manufacturing a semiconductor device by manufacturing a chip with a film-like adhesive to which an adhesive of the same size as that is attached and mounting the chip on a circuit board. Patent Document 2 below discusses a method in which a resin paste containing a solvent is applied onto a semiconductor wafer by spin coating, and the applied resin paste is made into a B-stage by heat drying.

JP 2006-049482 A JP 2009-38349 A

  In the method of Patent Document 1, when an adhesive layer is provided on the circuit surface of a semiconductor wafer having a circuit surface on which metal bumps are formed, a film adhesive is used so that no voids remain in the periphery of the bumps. It was difficult to paste.

  On the other hand, the method of Patent Document 2 uses a resin paste containing a solvent, and there is a problem that it takes a long time to be B-staged or the semiconductor wafer is contaminated by the solvent. In addition, there is a problem that the wafer warps after grinding due to heating for volatilizing the solvent. When drying at a low temperature, problems due to heating can be suppressed to some extent. However, in this case, since the residual solvent increases, voids and peeling occur at the time of pressure bonding and heat curing, and the reliability tends to decrease. In addition, if a low-boiling solvent is used for the purpose of lowering the drying temperature, the viscosity will change greatly during use, and the solvent will remain inside due to the volatilization of the solvent on the adhesive layer surface during drying. There was a tendency for the sex to decline.

  The present invention has been made in view of the above circumstances, and it is possible to obtain a semiconductor wafer with an adhesive layer in which the voids of the bump portions are sufficiently reduced and the warpage after grinding can be sufficiently reduced. It is an object of the present invention to provide a method for producing a semiconductor wafer with an adhesive layer, a method for producing a semiconductor device using such a semiconductor wafer with an adhesive layer, and a method for producing a semiconductor wafer with a semiconductor element.

  In order to solve the above problems, the present invention comprises a step of applying a liquid photosensitive adhesive on a circuit surface of a semiconductor wafer having a circuit surface on which metal bumps are formed, and forming a photosensitive adhesive layer, A step of obtaining a semiconductor wafer with an adhesive layer by subjecting the adhesive layer to B-stage by light irradiation, and cutting the semiconductor wafer of the semiconductor wafer with an adhesive layer together with the adhesive layer into a plurality of semiconductor elements to form an adhesive layer And a step of crimping a semiconductor element with an adhesive layer and another semiconductor element or a support member for mounting a semiconductor element with the adhesive layer of the semiconductor element with an adhesive layer interposed therebetween. A manufacturing method is provided.

  In the present invention, liquid means having fluidity at 25 ° C. and 1 atm.

  According to the method for manufacturing a semiconductor device of the present invention, by using a liquid photosensitive adhesive and forming an adhesive layer by forming a B-stage by light irradiation, the voids of the bump portion can be sufficiently reduced and also caused by heating. It is possible to obtain a semiconductor wafer with an adhesive layer that is less likely to cause defects. Thereby, the warp after grinding of the semiconductor wafer can be sufficiently reduced, a semiconductor element with an adhesive layer excellent in connectivity can be easily obtained, and a semiconductor device excellent in reliability can be manufactured. .

  In the method for producing a semiconductor device of the present invention, the liquid photosensitive adhesive contains (A) a radiation polymerizable compound, (B) a photoinitiator, and (C) a thermosetting resin, and (A) a component. Preferably contains a compound which is liquid at 25 ° C. and has one carbon-carbon double bond in the molecule.

  By using the liquid photosensitive adhesive, it can be applied on a substrate without using a solvent, and a thin adhesive layer can be formed by irradiating the coating with light. And since the heating for solvent drying is not required, the generation | occurrence | production of the pinhole by a heat flow and a volatile component can fully be suppressed. Furthermore, the above-described problems when using a conventional resin paste containing a solvent can be sufficiently solved.

  In the method for manufacturing a semiconductor device of the present invention, the liquid photosensitive adhesive preferably has a solvent content of 5% by mass or less or does not contain a solvent. Thereby, the tack force on the surface of the adhesive layer can be sufficiently reduced while further suppressing the generation of voids.

  Further, from the viewpoint of improving the coating property of the liquid photosensitive adhesive, reducing the thickness of the adhesive layer, and in-plane uniformity, the liquid photosensitive adhesive preferably has a viscosity at 25 ° C. of 10 to 30000 mPa · s. . The viscosity here is a value of viscosity measured at 25 ° C. under the conditions of a sample volume of 0.4 mL and a 3 ° cone using an EHD type rotational viscometer manufactured by Tokyo Keiki Seisakusho.

  Furthermore, it is preferable that the tack strength at 25 ° C. of the photosensitive adhesive layer B-staged by light irradiation is 200 gf or less. Thereby, the handleability after the B stage is further improved.

  Further, from the viewpoint of forming an adhesive layer having excellent film thickness uniformity, it is preferable to apply a liquid photosensitive adhesive by a spin coating method.

  The present invention also provides a semiconductor device obtained by the method for manufacturing a semiconductor device of the present invention.

  The present invention also includes a step of applying a liquid photosensitive adhesive on a circuit surface of a semiconductor wafer having a circuit surface on which metal bumps are formed to form a photosensitive adhesive layer; A step of obtaining a semiconductor wafer with an adhesive layer by B-stage by irradiation, and a step of obtaining a semiconductor element with an adhesive layer by cutting the semiconductor wafer of the semiconductor wafer with an adhesive layer together with the adhesive layer and dividing it into a plurality of semiconductor elements And a step of crimping the second semiconductor wafer and the semiconductor element with an adhesive layer between the adhesive layers of the semiconductor element with an adhesive layer, and a method for producing a semiconductor wafer with a semiconductor element.

  In the method for producing a semiconductor wafer with a semiconductor element of the present invention, the liquid photosensitive adhesive contains (A) a radiation polymerizable compound, (B) a photoinitiator, and (C) a thermosetting resin. The component A) preferably contains a compound that is liquid at 25 ° C. and has one carbon-carbon double bond in the molecule.

  The liquid photosensitive adhesive preferably has a solvent content of 5% by mass or less or does not contain a solvent.

  Further, from the viewpoint of improving the coating property of the liquid photosensitive adhesive, reducing the thickness of the adhesive layer, and in-plane uniformity, the liquid photosensitive adhesive preferably has a viscosity at 25 ° C. of 10 to 30000 mPa · s. .

  Furthermore, it is preferable that the tack strength at 25 ° C. of the photosensitive adhesive layer B-staged by light irradiation is 200 gf or less.

  Further, from the viewpoint of forming an adhesive layer having excellent film thickness uniformity, it is preferable to apply a liquid photosensitive adhesive by a spin coating method.

  The present invention also provides a semiconductor wafer with a semiconductor element obtained by the method for producing a semiconductor wafer with a semiconductor element of the present invention.

  The present invention also includes a step of applying a liquid photosensitive adhesive on a circuit surface of a semiconductor wafer having a circuit surface on which metal bumps are formed to form a photosensitive adhesive layer; And a process for producing a B-stage by irradiation.

  According to the method for manufacturing a semiconductor wafer with an adhesive layer of the present invention, it is possible to obtain a semiconductor wafer with an adhesive layer in which the voids of the bump portions are sufficiently reduced and the warpage after grinding can be sufficiently reduced. it can. According to such a semiconductor wafer with an adhesive layer, the warp after grinding of the semiconductor wafer can be sufficiently reduced, and a semiconductor element with an adhesive layer excellent in connectivity can be easily obtained, with high reliability. An excellent semiconductor device can be manufactured.

  In the method for producing a semiconductor wafer with an adhesive layer of the present invention, the liquid photosensitive adhesive contains (A) a radiation polymerizable compound, (B) a photoinitiator, and (C) a thermosetting resin. The component (A) preferably contains a compound that is liquid at 25 ° C. and has one carbon-carbon double bond in the molecule.

  The liquid photosensitive adhesive preferably has a solvent content of 5% by mass or less or does not contain a solvent.

  Further, from the viewpoint of improving the coating property of the liquid photosensitive adhesive, reducing the thickness of the adhesive layer, and in-plane uniformity, the liquid photosensitive adhesive preferably has a viscosity at 25 ° C. of 10 to 30000 mPa · s. .

  Furthermore, it is preferable that the tack strength at 25 ° C. of the photosensitive adhesive layer B-staged by light irradiation is 200 gf or less.

  Further, from the viewpoint of forming an adhesive layer having excellent film thickness uniformity, it is preferable to apply a liquid photosensitive adhesive by a spin coating method.

  This invention also provides the semiconductor wafer with an adhesive layer obtained by the manufacturing method of the semiconductor wafer with an adhesive layer of this invention.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor wafer with an adhesive bond layer can be obtained by exposure, without requiring the heating at the time of adhesive bond layer formation. Therefore, the B-stage can be realized in a short time, and the tact time at the time of manufacturing the semiconductor device can be greatly reduced. In addition, since the warpage of the semiconductor wafer after the B-stage can be suppressed, the semiconductor wafer can be thinned, and a highly functional semiconductor device can be obtained. Further, according to the present invention, it is possible to form a thin adhesive layer in a short time without using a solvent and without heating, so that heat energy and volatile organic compound (VOC) can be formed. It can be a material having a smaller environmental load than conventional ones.

It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a schematic diagram which shows one Embodiment of the manufacturing method of the semiconductor device which concerns on this invention. It is a mimetic diagram showing one embodiment of a semiconductor wafer with a semiconductor device concerning the present invention. It is a mimetic diagram showing one embodiment of a semiconductor device concerning the present invention. It is a schematic diagram which shows other embodiment of the semiconductor device which concerns on this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified, and the dimensional ratio in the drawing is not limited to the illustrated ratio.

  Hereinafter, a semiconductor device and a manufacturing method thereof according to the present invention will be specifically described with reference to the drawings. In recent years, semiconductor devices having various structures have been proposed, and the manufacturing method of the present invention is not limited to the semiconductor device having the structure described below and the manufacturing method thereof.

1 to 9 are schematic views showing an embodiment of a method for manufacturing a semiconductor device. The manufacturing method according to the present embodiment includes the following steps.
Step 1 (adhesive layer forming step): The liquid photosensitive adhesive 5 is applied to the circuit surface S1 of the semiconductor wafer 10 on which the metal bumps 12 are formed (see FIGS. 1 and 2).
Step 2 (B-staging step): Exposure is performed from the photosensitive adhesive layer side made of the applied liquid photosensitive adhesive, and the photosensitive adhesive layer is made into a B-stage. Thereby, the semiconductor wafer 50 with an adhesive layer is obtained (see FIGS. 3 and 4).
Step 3 (Back Grinding Tape Lamination Step): A peelable adhesive tape (back grinding tape) 30 is laminated on the adhesive layer 6 (see FIG. 5).
Step 4 (Back Grinding Step): The semiconductor wafer 10 is polished from the surface (back surface) S2 opposite to the circuit surface S1 to thin the semiconductor wafer 10 (see FIG. 6).
Step 5 (dicing tape lamination step): A peelable adhesive tape (dicing tape) 36 is laminated on the surface (back surface) opposite to the circuit surface S1 of the semiconductor wafer 10.
Step 6 (peeling step): The peelable adhesive tape 30 is peeled off (see FIG. 7).
Step 7 (dicing step): The semiconductor wafer 10 is cut into a plurality of semiconductor chips (semiconductor elements) 10a by dicing (see FIG. 8). Thereby, the semiconductor element 40 with an adhesive layer is obtained.
Step 8 (crimping step): The picked-up semiconductor element 40 with the adhesive layer is pressure-bonded (mounted) to a supporting member 15 for semiconductor device (supporting member for mounting a semiconductor element).
Step 9 (crimping step): The obtained laminated body is sealed with a sealing material (not shown) to obtain the semiconductor device 100.

  Hereinafter, each process is explained in full detail.

(Adhesive layer forming process)
The liquid photosensitive adhesive 5 is applied to the circuit surface S1 of the semiconductor wafer 10 having the circuit surface on which the metal bumps 12 are formed. The application can be performed in a state where the semiconductor wafer 10 to which the adhesive tape 4 is attached is fixed to the jig 21 in the box 20. The coating method is selected from a printing method, a spin coating method, a spray coating method, a jet dispensing method, an ink jet method, and the like. Among these, the spin coat method (FIG. 2 (a)) and the spray coat method (FIG. 2 (b)) are preferable from the viewpoints of thinning and film thickness uniformity. A hole may be formed in the suction table included in the spin coater, or the suction table may be mesh-shaped. It is preferable that the suction table has a mesh shape from the point that adsorption marks are difficult to remain. Application by spin coating is preferably performed at a rotational speed of 500 to 5000 rpm in order to prevent the wafer from undulating and the swell of the edge portion. From the same viewpoint, the rotational speed is more preferably 1000 to 4000 rpm. For the purpose of adjusting the viscosity of the liquid photosensitive adhesive, a temperature controller may be provided on the spin coat table.

  Although it does not specifically limit as a kind of metal bump in this invention, What is comprised with copper, silver, gold | metal | money, etc. is mentioned. In the present embodiment, solder balls 14 are further provided on the metal bumps 12. Examples of the solder ball 14 include those composed of a conventionally known solder material such as lead-containing solder or lead-free solder. As the metal bump, from the viewpoint of ease of production and cost, in the case of the metal bump, it is preferable that gold is difficult to produce an oxide film, and copper is inexpensive.

  As the semiconductor wafer, a wafer with bumps having protruding electrodes formed from copper bumps and solder balls can be used. The height of the protruding electrode (copper bump + solder ball) is about 20 to 60 μm. Further, although the thickness of the wafer varies depending on the wafer size, a wafer having a thickness of 625 to 775 μm before grinding can be used if the wafer is in the range of 6 inches to 12 inches.

    Regarding the thickness of the adhesive layer, from the viewpoints of the connectivity at the time of pressure bonding and the resin filling property, in the case of only metal bumps, the relationship between the bump height x1 and the thickness y of the adhesive layer satisfies x1 ≦ y. Preferably, 0.85 × 1 ≦ y ≦ 1.2 × 1 is satisfied. When there is a solder ball on the metal bump, the relationship between the metal bump height x2, the solder bump x3, and the thickness y of the adhesive layer preferably satisfies x2 ≦ y and x2 + x3 ≧ y.

  The liquid photosensitive adhesive can be stored in a syringe or the like, and a temperature controller may be provided in the syringe set portion of the spin coater.

  When a liquid photosensitive adhesive is applied to a semiconductor wafer by, for example, a spin coating method, an unnecessary liquid photosensitive adhesive may adhere to the edge portion of the semiconductor wafer. Such unnecessary adhesive can be removed by washing with a solvent after spin coating. By removing, contamination of the apparatus can be suppressed. A cleaning method is not particularly limited, but a method of discharging a solvent from a nozzle to a portion where an unnecessary adhesive is attached while spinning a semiconductor wafer is preferable. Any solvent may be used for the cleaning as long as it dissolves the adhesive. For example, a low boiling point solvent selected from methyl ethyl ketone, acetone, isopropyl alcohol and methanol is used.

  In addition, as a method of removing unnecessary adhesive on the edge portion of the semiconductor wafer, the adhesive layer is formed by removing the masking tape after spin-coating the adhesive on the semiconductor wafer on which the masking tape is previously attached to the edge portion. It can be formed in a target region.

(B-stage process)
An actinic ray (typically ultraviolet rays) is irradiated from the side of the photosensitive adhesive layer 5 formed from the liquid photosensitive adhesive by coating by the exposure device 9 to make the photosensitive adhesive layer into a B-stage. As a result, the B-staged adhesive layer 6 is fixed on the semiconductor wafer 10 and the tack on the surface of the adhesive layer 6 can be reduced. The thus obtained semiconductor wafer 50 with an adhesive layer is excellent in handleability, has sufficiently reduced voids in the bumps, and can sufficiently reduce warpage after grinding.

The exposure can be performed in an atmosphere such as a vacuum, nitrogen, or air. In order to reduce oxygen inhibition, exposure can be performed in a state where a base material such as a PET film or a polypropylene film subjected to a release treatment is laminated on the photosensitive adhesive layer. Moreover, you may expose in the state which laminated | stacked polyvinyl chloride, polyolefin, ethylene-vinyl acetate copolymer, a polyurethane, and an adhesive tape (back grind tape) on the photosensitive adhesive layer. Thereby, when performing the process of back grinding a semiconductor wafer after this process, it can move to a back grinding process as it is. The exposure amount is preferably ²⁰ to 2000 mJ / cm ² from the viewpoint of tack reduction and tact time. Moreover, you may heat at the temperature of 100 degrees C or less after exposure for the purpose of the tack | tuck reduction and outgas reduction after B-stage formation.

  It is also possible to perform exposure through a patterned mask. By using a patterned mask, it is possible to form adhesive layers having different fluidity during thermocompression bonding. By forming adhesive layers having different fluidity as described above, for example, the following can be performed. By performing exposure in a state where the metal bump portion is masked, an adhesive layer in which the metal bump portion is more excellent in thermocompression fluidity can be formed. Thereby, voids at the time of thermocompression bonding can be reduced, and oxide film removability (flux property) can be efficiently imparted.

(Back grinding process)
The semiconductor wafer can be thinned by back grinding after the B-stage process. That is, the semiconductor wafer may be thinned by polishing from the surface (back surface) opposite to the circuit surface of the semiconductor wafer. In this case, a peelable adhesive tape (back grind tape or the like) 30 is laminated on the adhesive layer 6. The adhesive tape 30 has a base material 31 and an adhesive layer 32. Instead of this adhesive tape, a flexible substrate such as polyvinyl chloride, polyolefin, ethylene-vinyl acetate copolymer, polyurethane or the like can be used. As a method of laminating the peelable adhesive tape, for example, a method of laminating a film previously formed into a film shape can be used.

  After the lamination, the semiconductor wafer 10 is polished from the surface (back surface) opposite to the circuit surface S1 of the semiconductor wafer 10 to reduce the thickness of the semiconductor wafer 10 to a predetermined thickness. The polishing is preferably performed using the grinding apparatus 34 in a state where the semiconductor wafer 10 is fixed to a polishing jig by the adhesive tape 30. In this step, the semiconductor wafer 10 is preferably thinned to a thickness of 10 to 150 μm. If the thickness of the thinned semiconductor wafer 10 is less than 10 μm, the semiconductor wafer is likely to be damaged. On the other hand, if the thickness exceeds 150 μm, it is difficult to meet the demand for miniaturization of the semiconductor device.

(Dicing process)
A peelable adhesive tape (dicing tape) 36 is laminated on the surface (back surface) opposite to the circuit surface S1 of the semiconductor wafer 10. The peelable adhesive tape 36 can be attached by a method of laminating an adhesive tape previously formed into a film shape.

  Next, the peelable adhesive tape (back grind tape) 30 is peeled off. For example, an adhesive tape whose adhesiveness is reduced by irradiation with actinic rays (typically ultraviolet rays) is used, and after exposure from the adhesive tape 30 side, it can be peeled off.

  The semiconductor wafer 10 is cut along with the adhesive layer 6 along the dicing line. By this dicing, the semiconductor wafer 10 is cut into a plurality of semiconductor chips (semiconductor elements) 10a each provided with an adhesive layer 6a on the back surface. The dicing is preferably performed using a dicing blade in a state where the whole is fixed to a frame (wafer ring) with an adhesive tape (dicing tape) 36. In this way, the semiconductor chip 40 with an adhesive layer is obtained.

(Crimping process)
After dicing, the cut semiconductor chip 10a is picked up together with the adhesive layer 6a by the die bonding apparatus, that is, the semiconductor chip 40 with the adhesive layer is picked up. Then, the semiconductor element 40 with an adhesive layer is pressure-bonded (mounted) to a semiconductor device support member (semiconductor element mounting support member) 15 having metal bumps or electrode pads 16. As described above, the semiconductor chip and the support member can be bonded and electrically connected by press-bonding the semiconductor chip with the adhesive layer and the support member with the adhesive layer of the semiconductor chip with the adhesive layer interposed therebetween.

  There are no problems as long as the bonding conditions are metal electrode bonding and solder ball melting, for example, temperature: 150 ° C. to 400 ° C., pressure: 0.1 MPa to 2.0 MPa, time: 1 second to If it is the range for about 30 seconds, said joining will be attained.

(Sealing process)
The semiconductor device 100 is obtained by sealing the stacked body including the semiconductor chip 10a with a sealing material.

  Through the above-described steps, a semiconductor device having a structure in which a semiconductor element and a semiconductor element mounting support member are bonded can be manufactured. The configuration and the manufacturing method of the semiconductor device are not limited to the above embodiment, and can be appropriately changed without departing from the gist of the present invention.

  For example, the order of steps 1 to 7 can be changed as necessary. More specifically, a liquid photosensitive adhesive can be applied to a circuit surface of a semiconductor wafer that has been diced in advance, and then an actinic ray (typically ultraviolet rays) can be irradiated to make the adhesive into a B-stage. . At this time, a patterned mask can also be used.

  In the adhesive layer forming step, after applying the liquid photosensitive adhesive to the circuit surface of the semiconductor wafer, the liquid temperature of the liquid photosensitive adhesive is reduced by heating the semiconductor wafer, applying ultrasonic waves, or vacuuming. By reducing the pressure in the chamber, voids around the bumps can be reduced.

  Moreover, after apply | coating and exposing a liquid photosensitive adhesive to the circuit surface of a semiconductor wafer, further applying a liquid photosensitive adhesive and exposing, a thick film adhesive layer can be obtained. At this time, it is also possible to obtain adhesive layers having different physical properties by applying and exposing liquid photosensitive adhesives having different compositions.

  The adhesive layer may be subjected to thermosetting treatment at 100 to 150 ° C. for 5 to 120 minutes after B-staging and thermocompression bonding. By such thermosetting treatment, voids and separation due to a high-temperature heat history process at 170 ° C. or higher can be suppressed, and a highly reliable semiconductor device can be obtained.

  Further, instead of the semiconductor element mounting support member in the crimping step, the semiconductor chip 40 with the adhesive layer can be crimped to a semiconductor wafer, another semiconductor element, or a substrate on which the semiconductor element is mounted.

  FIG. 10A is a diagram illustrating an example of a semiconductor wafer 70 with a semiconductor element in which a semiconductor chip 40 with an adhesive layer is pressure-bonded to a circuit surface of a semiconductor wafer 54 on which metal bumps are formed. FIG. 10B is a cross-sectional view taken along the line bb shown in FIG.

  The semiconductor wafer with a semiconductor element can be supplied as a member for manufacturing a semiconductor device.

  FIG. 11 is a diagram illustrating an example of a method for manufacturing a semiconductor device by press-bonding a semiconductor chip with an adhesive layer and another semiconductor chip. In the present embodiment, as shown in FIG. 11A, the circuit surface of the semiconductor chip 10b on which the metal bumps 12 are formed and the circuit surface of the semiconductor chip 40 with the adhesive layer are arranged to face each other. Crimp the. Thus, the semiconductor device 80 shown in FIG. 11B is obtained. Further, an adhesive layer may be formed on the circuit surface of the semiconductor chip 10b in the same manner as (a).

  FIG. 12 is a diagram illustrating an example of a method for manufacturing a semiconductor device by pressing a semiconductor chip with an adhesive layer and a substrate on which a semiconductor element is mounted. In this embodiment, as shown in FIG. 12A, a substrate on which a semiconductor element is mounted is prepared by forming metal bumps on the back surface of the semiconductor chip of the semiconductor device 100 obtained by the method described above. . Then, the circuit surface of the semiconductor chip 40 with the adhesive layer is disposed oppositely on the metal bump forming surface of the semiconductor chip 10b on which the metal bump is formed, and these are pressure-bonded. In this way, the semiconductor device 110 which is a stacked body including a plurality of semiconductor chips shown in FIG. 12B is obtained. One of the bumps 12 may be a pad.

  Next, the liquid photosensitive adhesive used in the method for manufacturing a semiconductor device according to the present invention will be described. In addition, this invention is not limited to the case where the liquid photosensitive adhesive demonstrated below is used.

  The liquid photosensitive adhesive can be used without particular limitation as long as it can be made into a B-stage by light irradiation. For example, a system that can be B-staged by a radical reaction by light, an anion reaction by light, a cation reaction by light, etc. Examples of the system for B-staging with a photoradical include a system containing a radiation polymerizable compound and a photoinitiator such as a photoradical initiator. Examples of the system that is B-staged with a photoanion include a system containing an epoxy resin and a photoanion generator. An example of a system for B-stage formation with a photocation is a system including an epoxy resin and a photocation generator. From the viewpoint of the time required for B-stage formation and storage stability after B-stage formation, a system capable of B-stage formation by radical reaction with light is preferable.

  In the present specification, the “B stage” means an intermediate stage of the curing reaction, that is, a stage where the melt viscosity is increased.

  The B-staged adhesive layer can be softened by heating. Specifically, it is preferable that the maximum value (maximum melt viscosity) of the melt viscosity at 20 ° C. to 60 ° C. of the B-staged adhesive layer is 5000 to 100000 Pa · s. From the viewpoint, it is more preferably 10,000 to 100,000 Pa · s. Moreover, it is preferable that the minimum value (minimum melt viscosity) of the melt viscosity at 60 ° C. to 200 ° C. of the B-staged adhesive layer is 10 to 30000 Pa · s, in view of good hot fluidity and connectivity. To 50 to 10,000 Pa · s.

Here, the maximum melt viscosity or the minimum melt viscosity is obtained by using a viscoelasticity measuring device ARES (manufactured by Rheometrics Scientific F.E. Co., Ltd.) for a sample after being exposed with a light amount of 1000 mJ / cm ^2. The maximum or minimum melt viscosity at 20 ° C. to 200 ° C. when measured. The measurement plate is a parallel plate having a diameter of 8 mm, the measurement conditions are a temperature increase of 5 ° C./min, the measurement temperature is 20 ° C. to 200 ° C., and the frequency is 1 Hz.

Further, the tack strength (surface tack force) at 25 ° C. of the B-staged adhesive layer is preferably 200 gf or less, more preferably 150 gf or less from the viewpoint of tackiness during thermocompression bonding. It is still more preferably 100 gf or less from the viewpoint of the peelability of the grind tape, and most preferably 50 gf or less from the viewpoint of reducing deposits during dicing. Moreover, it is preferable that the surface tack force is 0.1 gf / cm ² or more in order to suppress peeling of the adhesive layer during dicing. If the surface tack force is 0.1 gf / cm ² or less, water may enter the interface between the adhesive and the adherend during dicing, causing chip jumping. This is not preferable because it tends to cause a problem such as. On the other hand, when the surface tack force at 25 ° C. exceeds 200 gf / cm ² , the adhesiveness of the resulting adhesive layer at room temperature tends to be high, and the handleability tends to be poor.

The surface tack force here is a value measured as follows. A liquid photosensitive adhesive was applied onto a silicon wafer by spin coating so that the film thickness after the B stage was 35 μm, and the resulting coating film was subjected to a high-precision parallel exposure machine (Oak Manufacturing Co., Ltd.) at 25 ° C. in air. Manufactured by EXM-1172-B-∞ (product name)) at 1000 mJ / cm ² . Thereafter, the surface tack strength at 25 ° C. was measured using a probe tacking tester manufactured by Reska Co., Ltd., probe diameter: 5.1 mm, peeling speed: 10 mm / s, contact load: 100 gf / cm ² , contact time: 1 s Then, the tack force at 25 ° C. is measured five times, and the average value is calculated.

  In the present invention, the liquid photosensitive adhesive preferably contains (A) a radiation polymerizable compound, (B) a photoinitiator, and (C) a thermosetting resin. The adhesive having such a configuration can be an adhesive that can be B-staged by light irradiation.

  The liquid photosensitive adhesive according to this embodiment is preferably a liquid solvent-free photosensitive adhesive that is liquid at 1 atm and 25 ° C., and has a solvent content of 5 mass% or less. The above “solventless type” means that the amount of solvent contained in the adhesive is 5% by mass or less.

  The above solvent is a photopolymerizable group such as radiation polymerizable group, oxime ester group, α-aminoacetophenone, phosphine oxide, epoxy group, phenolic hydroxyl group, carboxyl group, amino group, acid anhydride, isocyanate, peroxide. An organic compound which does not have a thermally reactive group such as diazo group, imidazole or alkoxysilane, has a molecular weight of 500 or less and is liquid at room temperature (25 ° C.). Examples of such solvents include dimethylformamide, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, dioxane, cyclohexanone, ethyl acetate, γ-butyrolactone, and N-methyl-pyrrolidinone.

  When the amount of the solvent falls within the above range, tack can be reduced by light irradiation, and handling properties after light irradiation are improved. Furthermore, foaming during thermocompression bonding or heat curing can be suppressed.

  (A) Examples of the radiation polymerizable compound include compounds having an unsaturated bond between carbon atoms such as alkenes and alkynes.

  In the present invention, the radiation refers to ionizing radiation or non-ionizing radiation, for example, excimer laser light such as ArF or KrF, electron beam extreme ultraviolet light, vacuum ultraviolet light, X-ray, ion beam, i-ray, g Examples include ultraviolet light such as a line. As the radiation, ultraviolet light such as i-line or g-line is preferably used from the viewpoint of mass productivity.

  The liquid photosensitive adhesive of this embodiment preferably contains a compound that is liquid at 25 ° C. and has one carbon-carbon double bond in the molecule as the radiation-polymerizable compound (A). In the case of a composition containing a compound having two or more carbon-carbon double bonds in the molecule, it is in a state where a crosslinked structure is formed when irradiated with light, and is difficult to melt upon subsequent heating, and also exhibits tack. Therefore, thermocompression tends to be difficult. On the other hand, by containing a compound having one carbon-carbon double bond in the molecule, sufficient heat fluidity can be obtained, and thermocompression bonding can be improved. Of these, monofunctional (meth) acrylates are preferred because they can be B-staged with a low exposure amount.

  It is preferable that content of said monofunctional (meth) acrylate is 20-100 mass% with respect to (A) component whole quantity, It is more preferable that it is 40-100 mass%, It is 50-100 mass%. Most preferably it is. By making the compounding quantity of monofunctional (meth) acrylate into the said range, adhesiveness with the to-be-adhered body after B-staging and thermocompression bonding can be improved more.

  Further, the component (A) may be blended with a solid acrylate in addition to the compound which is liquid at 25 ° C. and has one carbon-carbon double bond in the molecule. In this case, the mixture of the component (A) is preferably liquid at 25 ° C.

  Further, from the viewpoint of obtaining a high level of thermal fluidity, it is preferable to contain, as the radiation polymerizable compound (A), a compound having one carbon-carbon double bond in the molecule alone in the adhesive composition. In addition, when a compound having one carbon-carbon double bond in the molecule is used alone, the molecular weight of the polymer obtained after light irradiation can be increased to several tens of thousands, and good adhesion and reliability after curing. Both sexes can be achieved. Here, when a compound having two or more carbon-carbon double bonds is included in the molecule, a network of polymers having a molecular weight of tens of thousands or more is formed, and the adhesiveness and fluidity during heat tend to be reduced. .

  The component (A) preferably has a viscosity at 25 ° C. of 5000 mPa · s or less from the viewpoint of the solubility of the other components such as the component (B) and the component (C), and further reduces the thickness. From the viewpoint of improving adhesion by adding a large amount of a solid or high-viscosity thermosetting resin, it is more preferably 1000 mPa · s or less, and even more preferably 2000 mPa · s or less. Most preferably: The viscosity here is the value of the entire component (A) contained in the adhesive, using an EHD rotational viscometer manufactured by Tokyo Keiki Seisakusho, under the conditions of a sample volume of 0.4 mL and a 3 ° cone. It is the value of the viscosity measured at ° C.

  When the viscosity of the component (A) exceeds 5000 mPa · s, the viscosity of the adhesive increases, and it tends to be difficult to reduce the thickness of the adhesive, or to discharge from a nozzle of a coating apparatus or the like. From the viewpoint of preventing the generation of pinholes during application and ensuring heat resistance, the viscosity of the component (A) at 25 ° C. is preferably 10 mPa · s or more.

  Further, the component (A) preferably has a 5% weight reduction temperature of 120 ° C. or more from the viewpoint of suppression of volatilization at the time of application, and the peeling caused by volatilization of the unreacted component (A) during thermosetting. It is even more preferable that the temperature is 150 ° C. or higher, and most preferable that the temperature is 180 ° C. or higher. Here, the 5% mass reduction temperature is the value of the entire component (A) contained in the adhesive, and the differential thermothermal gravimetric simultaneous measurement apparatus (TG / DTA6300 manufactured by SII Nanotechnology) is used as the component (A). Is a 5% weight loss temperature when measured under a heating rate of 10 ° C./min and under a nitrogen flow (400 ml / min).

  Further, from the viewpoint of lowering the viscosity of the adhesive, suppressing surface unevenness after coating, and thermal fluidity after B-stage, a material design mainly composed of an organic compound is preferable. Therefore, 5% by weight of the component (A) The decreasing temperature is preferably 500 ° C. or lower.

  Examples of the component (A) used in this embodiment include compounds having an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group, (meth) acryl group and the like. From the viewpoint of reactivity, the component (A) preferably contains a monofunctional (meth) acrylate. The monofunctional here means having one carbon-carbon double bond in the molecule, and may have other functional groups.

  Examples of the monofunctional (meth) acrylate include phenolic hydroxyl groups such as glycidyl group-containing (meth) acrylate, 4-hydroxyphenyl methacrylate, and 3,5-dimethyl-4-hydroxybenzylacrylamide in that the cured product can be toughened. Preferred are carboxyl group-containing (meth) acrylates such as containing (meth) acrylate, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxypropyl hexahydrophthalic acid, 2-methacryloyloxymethyl hexahydrophthalic acid, and heat resistance EO modified (meth) acrylate, phenol PO modified (meth) acrylate, nonylphenol EO modified (meth) acrylate, nonylphenol PO modified (meth) acrylate, phenoxyethyl (meth) acrylate Relate, phenoxyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, hydroxyethylated phenylphenol acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, Aromatic-containing (meth) acrylates such as nonylphenoxypolypropylene glycol (meth) acrylate, benzyl (meth) acrylate, 2-methacryloyloxyethyl 2-hydroxypropyl phthalate, and phenylphenol glycidyl ether acrylate are preferred, and adhesion after B-stage formation 2-Hydroxy-3-pheno in terms of imparting heat resistance and adhesiveness after thermosetting Cypropyl (meth) acrylate, O-phenylphenol glycidyl ether (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl-phthalic acid, 2- Hydroxy-3-phenoxypropyl (meth) acrylate, etc., hydroxyl group-containing (meth) acrylate represented by the following general formula (A-1) or (A-2), 2- (1,2-cyclohexacarboximide) ethyl acrylate The imide group-containing (meth) acrylate represented by the following general formula (A-3) or (A-4) is preferable, and the isobornyl-containing (meth) acrylate or dicyclopenta can be used to reduce the viscosity of the adhesive composition. Dienyl group-containing (meth) acrylate, isobornyl (meth) acrylate Relates are preferred. Among these, an imide group-containing (meth) acrylate is particularly preferably used because it can suppress repellency and pinholes when coated on a semiconductor wafer or an organic substrate, and can exhibit excellent adhesiveness after curing.

In the general formulas (A-1) and (A-2), R ₁ represents a hydrogen atom or a methyl group, R ₃ represents a monovalent organic group, and R ₂ and R ₄ each represents a divalent organic group. Indicates. R ₃ preferably has an aromatic group from the viewpoint of heat resistance. R ₄ preferably has an aromatic group from the viewpoint of heat resistance.

In the general formulas (A-3) and (A-4), R ₁ represents a hydrogen atom or a methyl group, R ₅ represents a divalent organic group, and R ₆ , R ₇ , R ₈ , R ₉ are Each represents a monovalent hydrocarbon group having 1 to 30 carbon atoms, R ₆ and R ₇ may be bonded to each other to form a ring, and R ₈ and R ₉ may be bonded to each other to form a ring; May be. When R ₆ and R ₇ , and R ₈ and R ₉ form a ring, examples thereof include a benzene ring structure and an alicyclic structure. The benzene ring structure and the alicyclic structure may have a thermosetting group such as a carboxyl group, a phenolic hydroxyl group, and an epoxy group, or may have an organic group such as an alkyl group.

  The compounds represented by the general formulas (A-3) and (A-4) are, for example, an N-hydroxyalkylimide compound obtained by reacting a monofunctional acid anhydride and ethanolamine, an acrylate ester or an acrylic ester. It can be synthesized by reacting with an acid ester by a known method. In this case, as the monofunctional acid anhydride, 4-phenylethynylphthalic anhydride, phthalic anhydride, maleic anhydride, succinic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, 2,5-norbornadiene- 2,3-dicarboxylic acid anhydride, maleic acid anhydride, trimellitic acid anhydride, cyclohexanedicarboxylic acid anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, cis-norbornene-endo-2,3-dicarboxylic acid Dicarboxylic anhydrides such as acid hexahydrophthalic anhydride, hexahydrophthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, etc. Can be used. Examples of the N-hydroxyalkylimide compound include N-hydroxyethylphthalimide and N-hydroxyethyl succinimide.

  The compounds represented by the above general formulas (A-3) and (A-4) include storage stability, low tack after B-stage, adhesion after B-stage, heat resistance after thermosetting, adhesion From the viewpoints of properties and reliability, compounds represented by the following general formulas (A-5) to (A-9) can be used as preferable ones, and from the viewpoint of low viscosity, the following general formula (A-5), The compounds represented by (A-7) to (A-9) can be used as more preferable ones.

上記式（Ａ−５）〜（Ａ−９）中、Ｒ１は、水素原子又はメチル基を示す。

In the above formulas (A-5) to (A-9), R1 represents a hydrogen atom or a methyl group.

  Moreover, as monofunctional (meth) acrylate, from a viewpoint of the adhesiveness with the adherend after B-stage formation, the adhesiveness after hardening, and heat resistance, a urethane group, an isocyanuric group, an imide group, a phenolic hydroxyl group, a hydroxyl group It is preferable to have either of these, and it is especially preferable that it is a monofunctional (meth) acrylate having an imide group in the molecule.

  In the liquid photosensitive adhesive of this embodiment, the compound which is liquid at 25 ° C. and has one carbon-carbon double bond in the molecule may be blended alone or in combination of two or more. it can.

Furthermore, in the monofunctional (meth) acrylate, the Tg of the polymer obtained by polymerizing the monofunctional (meth) acrylate is 100 ° C. or less from the viewpoint of thermocompression bonding after B-stage and fluidity during heat. Those having a Tg of 20 ° C. or higher are preferable from the viewpoint of B-stage. The Tg of the monofunctional (meth) acrylate polymer is a ratio of 3% by mass with respect to the monofunctional (meth) acrylate of I-379EG (manufactured by Ciba Japan), which is a photoinitiator, to the monofunctional (meth) acrylate. The composition dissolved in (1) was applied on a PET (polyethylene terephthalate) film so as to have a film thickness of 35 μm, and this coating film was coated with a high-precision parallel exposure machine (Oak Seisakusho, product name: EXM) at room temperature and under air. -1172-B-∞), a viscoelasticity measuring device (Rheometrics Scientific F.) was used for a laminate obtained by laminating films obtained by exposure at 1000 mJ / cm ² to a film thickness of 150 μm. It is a tan δ peak temperature at −50 ° C. to 200 ° C. measured using E Co., Ltd., product name: ARES). The measurement plate is a parallel plate having a diameter of 8 mm, and the measurement conditions are a heating rate of 5 ° C./min, a measurement temperature of −50 ° C. to 200 ° C., and a frequency of 1 Hz.

  The content of the component (A) is preferably 10 to 95% by mass, more preferably 20 to 90% by mass, and most preferably 40 to 90% by mass with respect to the total amount of the adhesive composition. preferable. When the content of the component (A) is less than 10% by mass, the surface tack force after exposure tends to increase, and when it exceeds 95% by mass, the adhesive strength after thermosetting tends to decrease. .

  (B) The photoinitiator preferably has a molecular extinction coefficient with respect to light having a wavelength of 365 nm of 100 ml / g · cm or more in terms of enabling B-stage, and can further reduce tack after exposure. What is 200 ml / g · cm or more is more preferable, and what is 400 ml / g · cm or more is more preferable in that oxygen inhibition can be further reduced, and the B-stage can be formed in a low exposure amount and in a short time. Most preferable is 1000 ml / g · cm or more. Note that the time required for the B-stage is preferably within 60 s, and more preferably within 30 s in that a semiconductor device can be more efficiently manufactured. For the molecular extinction coefficient, a 0.001% by mass acetonitrile solution of the sample is prepared, and the absorbance of this solution is measured using a spectrophotometer (manufactured by Hitachi High-Technologies Corporation, “U-3310” (product name)). Is required.

  Examples of the component (B) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy)- Phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2 -Methyl-propan-1-one, oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] ethyl ester, phenylglyoxylic acid methyl ester, 2-dimethylamino-2- (4- Methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one, 2-ethylhexyl 4-di Tylaminobenzoate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl -Ketones, aromatic ketones such as 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropanone-1,2,4-diethylthioxanthone, 2-ethylanthraquinone, phenanthrenequinone, benzyldimethyl ketal, etc. Benzyl derivative, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o -Fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) Nyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer , 2,4,5-triarylimidazole dimer such as 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine, 1,7-bis (9, Acridine derivatives such as 9'-acridinyl) heptane, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6, -trimethylbenzoyl) -phenylphosphine Examples thereof include bisacylphosphine oxides such as oxides and compounds having maleimide. These can be used alone or in combination of two or more.

  (B) The photoinitiator is a compound having an oxime ester skeleton or a morpholine skeleton in the molecule in that it can be efficiently B-staged by exposure even in an air atmosphere (in the presence of oxygen). Preferably there is. Although it does not specifically limit as such a compound, The compound which has an oxime ester group represented by the following general formula (B-1), and / or the following general formula (B-2), (B-3) or (B- A compound having a morpholine ring represented by 4) is preferred. Specifically, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- (4- (Methylthio) phenyl) -2-morpholinopropan-1-one is preferably used.

式中、Ｒ^５１及びＲ^５２はそれぞれ独立に、水素原子、炭素数１〜７のアルキル基、又は芳香族系炭化水素基を含む有機基を示し、Ｒ^５３及びＲ^５４及びＲ^５５は、炭素数１〜７のアルキル基、又は芳香族系炭化水素基を含む有機基を示し、Ｒ^５６及びＲ^５７は、芳香族系炭化水素基を含む有機基を示す。

In the formula, R ⁵¹ and R ⁵² each independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or an organic group containing an aromatic hydrocarbon group, and R ^53, R ^54, and R ⁵⁵ represent carbon number 1-7 alkyl group, or an organic group containing an aromatic hydrocarbon group, R ⁵⁶ and R ⁵⁷ are an organic group containing an aromatic hydrocarbon group.

  Although it does not restrict | limit especially as said aromatic hydrocarbon group, For example, a phenyl group and a naphthyl group, a benzoin derivative, a carbazole derivative, a thioxanthone derivative, a benzophenone derivative etc. are mentioned. Moreover, the aromatic hydrocarbon group may have a substituent.

  Particularly preferable as the (B) photoinitiator is a compound having an oxime ester group and / or a morpholine ring, which has a molecular extinction coefficient of 1000 ml / g · cm or more with respect to light having a wavelength of 365 nm and a mass loss of 5%. A compound having a temperature of 150 ° C. or higher.

  Examples of such (B) photoinitiator include compounds represented by the following structural formulas (B-5) to (B-9).

  The content of the (B) photoinitiator is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the component (A), from the viewpoint of B-stage tact and B-stage tuck. More preferably, it is 0.5-10 mass parts. If this content exceeds 20 parts by mass, the outgas will increase and the adhesiveness will tend to decrease, and the storage stability will tend to decrease. On the other hand, when the content is less than 0.1 parts by mass, it tends to be difficult to make a B stage.

  In the liquid photosensitive adhesive of this embodiment, a sensitizer can be used in combination as necessary. Examples of the sensitizer include camphorquinone, benzyl, diacetyl, benzyldimethyl ketal, benzyl diethyl ketal, benzyl di (2-methoxyethyl) ketal, 4,4′-dimethylbenzyl-dimethyl ketal, anthraquinone, 1-chloroanthraquinone. 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, Oxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, isopropyl ether, benzoin isobutyl ether, benzophenone, bis (4-dimethylaminophenyl) ketone, 4,4′-bisdiethylaminobenzophenone, Examples thereof include a compound containing an azide group. These can be used alone or in combination of two or more. Among the sensitizers, 4,4′-bisdiethylaminobenzophenone is most preferably used in that the tack after the B stage can be further reduced.

  The (C) thermosetting resin is not particularly limited as long as it is a component composed of a reactive compound that undergoes a crosslinking reaction by heat. For example, epoxy resin, cyanate ester resin, maleimide resin, allyl nadiimide resin Phenol resin, urea resin, melamine resin, alkyd resin, acrylic resin, unsaturated polyester resin, diallyl phthalate resin, silicone resin, resorcinol formaldehyde resin, xylene resin, furan resin, polyurethane resin, ketone resin, triallyl cyanurate resin, Polyisocyanate resin, resin containing tris (2-hydroxyethyl) isocyanurate, resin containing triallyl trimellitate, thermosetting resin synthesized from cyclopentadiene, thermosetting by trimerization of aromatic dicyanamide Tree Etc. The. Among these, an epoxy resin is preferable in that it can have an excellent adhesive force at high temperatures. In addition, a thermosetting resin can be used individually or in combination of 2 or more types.

  As an epoxy resin, what contains at least 2 or more epoxy group in a molecule | numerator is preferable, and the point of the thermocompression bonding property, sclerosis | hardenability, and hardened | cured material characteristic has more preferable the glycidyl ether type epoxy resin of a phenol. Examples of such resins include bisphenol A type (or AD type, S type, and F type) glycidyl ether, water-added bisphenol A type glycidyl ether, ethylene oxide adduct bisphenol A type glycidyl ether, and propylene oxide adduct. Bisphenol A type glycidyl ether, phenol novolac resin glycidyl ether, cresol novolac resin glycidyl ether, bisphenol A novolac resin glycidyl ether, naphthalene resin glycidyl ether, trifunctional (or tetrafunctional) glycidyl ether, dicyclo Examples include glycidyl ether of pentadienephenol resin, glycidyl ester of dimer acid, trifunctional (or tetrafunctional) glycidylamine, glycidylamine of naphthalene resin, etc. It is. These can be used alone or in combination of two or more.

  As the epoxy resin, it is possible to use a high-purity product in which impurity ions such as alkali metal ions, alkaline earth metal ions, halogen ions, particularly chlorine ions and hydrolyzable chlorine are reduced to 300 ppm or less. From the viewpoint of prevention and corrosion prevention of metal conductor circuits.

  (C) The thermosetting resin can be used regardless of liquid or solid at room temperature. In the case of a liquid thermosetting resin, the viscosity can be further reduced, and in the case of a solid thermosetting resin, tack after light irradiation can be further reduced. Moreover, you may use together a liquid thermosetting resin and a solid thermosetting resin.

  When a liquid thermosetting resin is used, the viscosity is preferably 10,000 mPa · s or less, more preferably 5000 mPa · s or less, still more preferably 3000 mPa · s or less, and even more preferably 2000 mPa · s or less. Most preferably. When the viscosity exceeds 10,000 mPa · s, the viscosity of the adhesive composition increases and it tends to be difficult to form a thin film. Such a liquid thermosetting resin is not particularly limited, but is preferably an epoxy resin from the viewpoint of adhesiveness and heat resistance, and particularly a trifunctional (or tetrafunctional) glycidylamine or bisphenol A type (or AD type, S type, and F type glycidyl ethers are preferably used.

  When using a solid thermosetting resin, it can be dissolved in the component (A), for example. Although it does not specifically limit as solid thermosetting resin, From a viewpoint of thermocompression bonding property and viscosity, it is preferable that molecular weight is 2000 or less, Preferably it is 1000 or less, and a softening point is 100 degrees C or less, Preferably it is 80 degrees C The following is preferable. In addition, a trifunctional or higher functional epoxy resin is preferable from the viewpoint of adhesiveness and heat resistance. As such an epoxy resin, for example, an epoxy resin having the following structure is preferably used.

ｎは、０〜１０の整数を示す。

n shows the integer of 0-10.

  The (C) thermosetting resin preferably has a 5% weight loss temperature of 150 ° C. or higher, more preferably 180 ° C. or higher, and even more preferably 200 ° C. or higher. Here, the 5% mass reduction temperature of the thermosetting resin means that the thermosetting resin is heated at a rate of 10 ° C./temperature using a differential thermothermal gravimetric simultaneous measurement apparatus (manufactured by SII Nanotechnology: TG / DTA6300). Min, 5% weight loss temperature when measured under a nitrogen flow (400 ml / min). By applying a thermosetting resin having a high 5% weight loss temperature, volatilization during thermocompression bonding or thermosetting can be suppressed. Examples of such a thermosetting resin having heat resistance include an epoxy resin having an aromatic group in the molecule.

  (C) The content of the thermosetting resin is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the component (A), and 2 to 50 parts by mass from the viewpoint of both storage stability and B-stage formation. It is more preferable that When this content exceeds 100 parts by mass, the tack after exposure tends to increase. On the other hand, when the content is less than 2 parts by mass, there is a tendency that sufficient high-temperature adhesiveness cannot be obtained.

  The liquid photosensitive adhesive of this embodiment preferably further contains a curing accelerator. The curing accelerator is not particularly limited as long as it is a compound that accelerates curing / polymerization of the epoxy resin by heating. For example, a phenol compound, an aliphatic amine, an alicyclic amine, an aromatic polyamine, polyamide, an aliphatic acid anhydride , Alicyclic acid anhydride, aromatic acid anhydride, dicyandiamide, organic acid dihydrazide, boron trifluoride amine complex, imidazoles, dicyandiamide derivatives, dicarboxylic acid dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2 -Ethyl-4-methylimidazole-tetraphenylborate, 1,8-diazabicyclo [5.4.0] undecene-7-tetraphenylborate, tertiary amine and the like. Among these, imidazoles are preferably used from the viewpoint of solubility and dispersibility when no solvent is contained. As for content of a hardening accelerator, 0.01-50 mass parts is preferable with respect to 100 mass parts of epoxy resins. Also, imidazoles are particularly preferable from the viewpoints of adhesiveness, heat resistance, and storage stability.

  As imidazoles, the reaction initiation temperature is preferably 50 ° C. or higher, and more preferably 80 ° C. or higher. When the reaction start temperature is 50 ° C. or lower, the storage stability is lowered, so that the viscosity of the resin composition is increased and the control of the film thickness becomes difficult.

  As imidazoles, it is preferable to use imidazoles that are soluble in epoxy resins. By using such imidazole, a coating film with less unevenness can be obtained. Such imidazoles are not particularly limited, but 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole and the like. From the viewpoints of storage stability, adhesiveness, and heat resistance, 1-benzyl-2-phenylimidazole is particularly preferably used.

  As the imidazoles, a compound pulverized to an average particle size of preferably 10 μm or less, more preferably 8 μm or less, and most preferably 5 μm or less can be used. By using imidazoles having such a particle size, the viscosity change of the adhesive can be suppressed, and precipitation of imidazoles can be suppressed. In addition, when the thin film is formed, surface irregularities can be reduced, and thereby a uniform film can be obtained. Furthermore, since the curing in the resin can proceed uniformly during curing, outgas can be reduced.

  Moreover, the liquid photosensitive adhesive of this embodiment may contain a phenol compound as a curing agent. As the phenolic compound, a phenolic compound having at least two phenolic hydroxyl groups in the molecule is more preferable. Examples of such compounds include phenol novolak, cresol novolak, t-butylphenol novolak, dicyclopentadiene cresol novolak, dicyclopentadiene phenol novolak, xylylene-modified phenol novolak, naphthol compound, trisphenol compound, tetrakisphenol novolak, bisphenol. A novolak, poly-p-vinylphenol, phenol aralkyl resin and the like. Among these, those having a number average molecular weight in the range of 400 to 4000 are preferable. Thereby, the outgas at the time of heating which causes the contamination of the semiconductor element or the device at the time of assembling the semiconductor device can be suppressed. The phenolic compound is preferably liquid, and the allyl-modified phenol novolak is preferably used because it is liquid and highly heat resistant.

  The content of the phenolic compound is preferably 50 to 100 parts by mass and more preferably 60 to 95 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  The liquid photosensitive adhesive of this embodiment can further contain (D) a thermal radical generator. The thermal radical generator is preferably an organic peroxide from the viewpoints of storage stability and reactivity. The organic peroxide preferably has a 1 minute half-life temperature of 80 ° C. or higher, more preferably 100 ° C. or higher, and most preferably 120 ° C. or higher. The organic peroxide is selected in consideration of the preparation conditions of the adhesive composition, film forming temperature, pressure bonding, curing conditions, other process conditions, storage stability, and the like. Although it does not specifically limit as a peroxide which can be used, For example, 2,5-dimethyl-2,5-di (t-butylperoxyhexane), dicumyl peroxide, t-butylperoxy-2 -Ethyl hexanate, t-hexyl peroxy-2-ethyl hexanate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexyl peroxy) ) -3,3,5-trimethylcyclohexane, bis (4-t-butylcyclohexyl) peroxydicarbonate, etc., and one of these may be used alone or in combination of two or more. it can. By containing the above organic peroxide, the unreacted radiation-polymerizable compound remaining after exposure can be reacted, and low outgassing and high adhesion can be achieved.

  Examples of the thermal radical generator having a one-minute half-life temperature of 80 ° C. or higher include perhexa 25B (manufactured by NOF Corporation), 2,5-dimethyl-2,5-di (t-butylperoxyhexane) ( 1 minute half-life temperature: 180 ° C.), Parkmill D (manufactured by NOF Corporation), dicumyl peroxide (1 minute half-life temperature: 175 ° C.), and the like.

  (D) The content of the thermal radical generator is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and more preferably 0.5 to 5%, based on the total amount of the (A) radiation polymerizable compound. Mass% is most preferred. When the content of the thermal radical generator is less than 0.01% by mass, the curability is lowered and the effect of addition is reduced, and when it exceeds 5% by mass, the outgas amount is increased and the storage stability is decreased.

  The liquid photosensitive adhesive of the present embodiment improves the film thickness uniformity after coating, thermocompression bonding after B-stage, low stress after thermosetting, and adhesion to the adherend ( E) A thermoplastic resin may be further contained.

  (E) It is preferable that Tg of a component is 150 degrees C or less, It is more preferable that it is 120 degrees C or less, It is still more preferable that it is 100 degrees C or less, It is most preferable that it is 80 degrees C or less. When this Tg exceeds 150 ° C., the viscosity of the adhesive composition tends to increase. Further, a high temperature of 150 ° C. or higher is required for thermocompression bonding to the adherend, and the semiconductor wafer tends to be warped.

  Here, “Tg” of the component (E) means a main dispersion peak temperature when the component (E) is formed into a film. Specifically, for the film of component (E), using a viscoelasticity analyzer “RSA-2” (product name) manufactured by Rheometrics, the film thickness is 100 μm, the heating rate is 5 ° C./min, the frequency is 1 Hz, and the measurement temperature. The measurement is performed at −150 to 300 ° C., and the tan δ peak temperature near Tg is obtained as Tg.

  (E) It is preferable that the weight average molecular weight of a component is controlled within the range of 5000-500000. Furthermore, as for the weight average molecular weight of (E) component, it is more preferable that it is 10,000 to 300,000 at the point which can make thermocompression bonding property and high temperature adhesiveness highly compatible. Here, the “weight average molecular weight” means the weight average molecular weight when measured in terms of polystyrene using high performance liquid chromatography “C-R4A” (product name) manufactured by Shimadzu Corporation.

  Examples of the component (E) include polyester resins, polyether resins, polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, polyurethane resins, polyurethaneimide resins, polyurethaneamideimide resins, siloxane polyimide resins, and polyesterimide resins. In addition to these copolymers and their precursors (polyamide acid, etc.), polybenzoxazole resin, phenoxy resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, polyester resin, polyether resin, polycarbonate resin, poly Examples thereof include ether ketone resins, (meth) acrylic copolymers having a weight average molecular weight of 10,000 to 1,000,000, novolac resins, and phenol resins. These can be used individually by 1 type or in combination of 2 or more types. In addition, the main chain and / or side chain of these resins may be provided with a glycol group such as ethylene glycol or propylene glycol, a carboxyl group, and / or a hydroxyl group.

  The content of the thermoplastic resin is preferably 0.1 to 50% by mass with respect to the component (A), and more preferably 0.5 to 20% by mass from the viewpoint of film formability, film thickness uniformity, and viscosity increase suppression. preferable. If the content of the thermoplastic resin is less than 0.1% by mass, the effect of addition tends to be lost, and if it exceeds 50% by mass, the film thickness uniformity decreases due to undissolved or the like. It tends to rise and make thinning difficult.

  The liquid photosensitive adhesive of this embodiment is prohibited from polymerization of quinones, polyphenols, phenols, phosphites, sulfurs, etc. in order to impart storage stability, process adaptability or antioxidant properties. You may further add an agent or antioxidant in the range which does not impair sclerosis | hardenability.

  Moreover, the liquid photosensitive adhesive of this embodiment can also contain a filler as appropriate. Examples of the filler include metal fillers such as silver powder, gold powder, copper powder, and nickel powder, alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, Inorganic fillers such as aluminum oxide, aluminum nitride, crystalline silica, amorphous silica, boron nitride, titania, glass, iron oxide, and ceramics, and organic fillers such as carbon and rubber fillers are included. Regardless, it can be used without any particular restrictions.

  The filler can be used properly according to the desired function. For example, the metal filler is added for the purpose of imparting conductivity, thermal conductivity, thixotropy, etc. to the adhesive composition, and the nonmetallic inorganic filler is thermally conductive, low thermal expansion, low hygroscopicity to the adhesive layer. The organic filler is added for the purpose of imparting toughness to the adhesive layer.

  These metal fillers, inorganic fillers, or organic fillers can be used singly or in combination of two or more. Among them, metal fillers, inorganic fillers, or insulating fillers are preferable in terms of being able to impart conductivity, thermal conductivity, low moisture absorption characteristics, insulating properties, and the like required for adhesive materials for semiconductor devices, and inorganic fillers or insulating fillers. Among the fillers, a silica filler is more preferable in that the dispersibility with respect to the adhesive composition is good and a high adhesive force during heating can be imparted.

  The filler preferably has an average particle size of 10 μm or less and a maximum particle size of 30 μm or less, more preferably an average particle size of 5 μm or less and a maximum particle size of 20 μm or less. If the average particle size exceeds 10 μm or the maximum particle size exceeds 30 μm, the effect of improving fracture toughness tends to be insufficient. Further, the lower limits of the average particle size and the maximum particle size are not particularly limited, but both are preferably 0.001 μm or more.

  Although content of the said filler is determined according to the characteristic or function to provide, it is preferable that it is 50 mass% or less with respect to the adhesive agent whole quantity containing a filler, 1-40 mass% is more preferable, 3-30 More preferred is mass%. By increasing the amount of filler, low thermal expansion, low moisture absorption, and high elastic modulus can be achieved, and dicing properties (cutability with a dicer blade) and adhesive strength during heating can be effectively improved. If the amount of filler is increased more than necessary, the viscosity tends to increase or the thermocompression bonding property tends to be impaired. Therefore, the filler content is preferably within the above range. The optimum filler content can be determined to balance the required properties. Mixing and kneading in the case of using a filler can be carried out by appropriately combining dispersers such as ordinary stirrers, raking machines, three rolls, and ball mills.

  Various coupling agents can be added to the liquid photosensitive adhesive of this embodiment in order to improve the interfacial bonding between different materials. Examples of the coupling agent include silane-based, titanium-based, and aluminum-based. Among them, a silane-based coupling agent is preferable because of its high effect, and a thermosetting group such as an epoxy group, methacrylate, and / or acrylate. A compound having a radiation polymerizable group such as is more preferred.

  Among the above fillers, silica fillers are preferably used from the viewpoint of compatibility with other resin components and high-temperature adhesiveness, and silica fillers treated with silane coupling agents such as epoxy, acrylate, and phenyl are most preferable. Used.

  The boiling point and / or decomposition temperature of the silane coupling agent is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, and even more preferably 200 ° C. or higher. In particular, a silane coupling agent having a boiling point of 200 ° C. or higher and / or a decomposition temperature and having a thermosetting group such as an epoxy group and a radiation polymerizable group such as methacrylate and / or acrylate is most preferably used.

  It is preferable that the usage-amount of the said coupling agent shall be 0.01-20 mass parts with respect to 100 mass parts of adhesive agents from the surface of the effect, heat resistance, and cost.

  In the liquid photosensitive adhesive of this embodiment, an ion scavenger may be further added to adsorb ionic impurities and improve insulation reliability during moisture absorption. Such an ion scavenger is not particularly limited. For example, triazine thiol compound, a compound known as a copper damage preventer for preventing copper from being ionized and dissolved, such as a phenol-based reducing agent, Inorganic compounds such as bismuth-based, antimony-based, magnesium-based, aluminum-based, zirconium-based, calcium-based, titanium-based, zuzu-based, and mixed systems thereof. Specific examples include inorganic ion scavengers manufactured by Toa Gosei Co., Ltd., product names, IXE-300 (antimony type), IXE-500 (bismuth type), IXE-600 (antimony, bismuth mixed type), IXE-700. (Magnesium and aluminum mixed system), IXE-800 (zirconium system), IXE-1100 (calcium system) and the like. These may be used alone or in combination of two or more. The amount of the ion scavenger used is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the adhesive from the viewpoint of the effect of addition, heat resistance, cost, and the like.

  The liquid photosensitive adhesive of this embodiment preferably contains a fluxing agent in order to reduce and remove the oxide film on the surface such as solder and facilitate metal bonding.

  As the fluxing agent, it is desirable to use at least one compound selected from alcohols, phenols, and carboxylic acids.

  The alcohol is not particularly limited as long as it is a compound having at least two alcoholic hydroxyl groups in the molecule. For example, 1,3-dioxane-5,5-dimethanol, 1,5-pentanediol, 2 , 5-furandiethanol, diethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, 1,2,3-hexanetriol, 1,2,4-butanetriol, 1,2,6-hexanetriol, 3-methyl Pentane-1,3,5-triol, glycerin, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol, ribitol, sorbitol, 2,4-diethyl-1,5-pentanediol, propylene glycol monomethyl ether, propylene group Cole monoethyl ether, 1,3-butylene glycol, 2-ethyl-1,3-hexanediol, N-butyldiethanolamine, N-ethyldiethanolamine, diethanolamine, triethanolamine, N, N-bis (2-hydroxyethyl) Isopropanolamine, bis (2-hydroxymethyl) iminotris (hydroxymethyl) methane, N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, 1,1 ′, 1 ″, 1 ′ ″ − (Ethylenedinitrilo) tetrakis (2-propanol) and the like can be used. Among them, compounds having a tertiary nitrogen atom such as N-butyldiethanolamine, N-ethyldiethanolamine, triethanolamine, N, N-bis (2-hydroxyethyl) isopropanolamine, bis (2-hydroxymethyl) iminotris (hydroxy) Methyl) methane, N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, 1,1 ′, 1 ″, 1 ′ ″-(ethylenedinitrilo) tetrakis (2-propanol) Compared with other compounds, it is desirable because it exhibits a good flux activity. Although the detailed reason for showing good flux activity is not clear, the ability to reduce oxide film by alcoholic hydroxyl group and the ability to reduce by electron donating property derived from unpaired electrons on the tertiary nitrogen atom act together. It is presumed to be caused. These compounds may be used alone or in combination of two or more.

  The phenol is not particularly limited as long as it is a compound having at least two phenolic hydroxyl groups. For example, catechol, resorcinol, hydroquinone, biphenol, dihydroxynaphthalene, hydroxyhydroquinone, pyrogallol, methylidene biphenol (bisphenol F), Examples thereof include isopropylidene biphenol (bisphenol A), ethylidene biphenol (bisphenol AD), 1,1,1-tris (4-hydroxyphenyl) ethane, trihydroxybenzophenone, trihydroxyacetophenone, and poly p-vinylphenol. Furthermore, as a compound having at least two phenolic hydroxyl groups, at least one compound selected from compounds having at least one phenolic hydroxyl group in the molecule and a halomethyl group, alkoxymethyl group or hydroxylmethyl group in the molecule A polycondensate with at least one compound selected from the group consisting of two aromatic compounds, divinylbenzene and aldehydes can also be used. Examples of the compound having at least one phenolic hydroxyl group in the molecule include phenol, alkylphenol, naphthol, cresol, catechol, resorcinol, hydroquinone, biphenol, dihydroxynaphthalene, hydroxyhydroquinone, pyrogallol, methylidene biphenol (bisphenol F), Examples thereof include isopropylidene biphenol (bisphenol A), ethylidene biphenol (bisphenol AD), 1,1,1-tris (4-hydroxyphenyl) ethane, trihydroxybenzophenone, trihydroxyacetophenone, and poly p-vinylphenol. Examples of the aromatic compound having two halomethyl groups, alkoxymethyl groups or hydroxylmethyl groups in the molecule include 1,2-bis (chloromethyl) benzene, 1,3-bis (chloromethyl) benzene, 1 , 4-bis (chloromethyl) benzene, 1,2-bis (methoxymethyl) benzene, 1,3-bis (methoxymethyl) benzene, 1,4-bis (methoxymethyl) benzene, 1,2-bis (hydroxy) And methyl) benzene, 1,3-bis (hydroxymethyl) benzene, 1,4-bis (hydroxymethyl) benzene, bis (chloromethyl) biphenyl, and bis (methoxymethyl) biphenyl. Examples of aldehydes include formaldehyde (formalin as an aqueous solution thereof), paraformaldehyde, trioxane, hexamethylenetetramine and the like. Examples of the polycondensate include a phenol novolac resin that is a polycondensate of phenol and formaldehyde, a cresol novolac resin that is a polycondensate of cresol and formaldehyde, a naphthol novolac resin that is a polycondensate of naphthols and formaldehyde, Phenol aralkyl resin, which is a polycondensation product of phenol and 1,4-bis (methoxymethyl) benzene, polycondensation product of bisphenol A and formaldehyde, polycondensation product of phenol and divinylbenzene, polycondensation of cresol, naphthol and formaldehyde These may be those obtained by modifying these polycondensates with rubber, or by introducing an aminotriazine skeleton or dicyclopentadiene skeleton into the molecular skeleton. Furthermore, examples of the compounds that have been liquefied by allylating these compounds having a phenolic hydroxyl group include allylated phenol novolac resins, diallyl bisphenol A, diallyl bisphenol F, diallyl biphenol, and the like. These compounds may be used alone or in combination of two or more.

  The carboxylic acids may be either aliphatic carboxylic acids or aromatic carboxylic acids. Examples of the aliphatic carboxylic acid include malonic acid, methylmalonic acid, dimethylmalonic acid, ethylmalonic acid, allylmalonic acid, 2,2′-thiodiacetic acid, 3,3′-thiodipropionic acid, 2,2′- (Ethylenedithio) diacetic acid, 3,3′-dithiodipropionic acid, 2-ethyl-2-hydroxybutyric acid, dithiodiglycolic acid, diglycolic acid, acetylenedicarboxylic acid, maleic acid, malic acid, 2-isopropylmalic acid , Tartaric acid, itaconic acid, 1,3-acetone dicarboxylic acid, tricarbaric acid, muconic acid, β-hydromuconic acid, succinic acid, methyl succinic acid, dimethyl succinic acid, glutaric acid, α-ketoglutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, 2,2-bis (hydroxymethyl) ) Propionic acid, citric acid, adipic acid, 3-tert-butyladipic acid, pimelic acid, phenyloxalic acid, phenylacetic acid, nitrophenylacetic acid, phenoxyacetic acid, nitrophenoxyacetic acid, phenylthioacetic acid, hydroxyphenylacetic acid, dihydroxyphenylacetic acid, Mandelic acid, hydroxymandelic acid, dihydroxymandelic acid, 1,2,3,4-butanetetracarboxylic acid, suberic acid, 4,4'-dithiodibutyric acid, cinnamic acid, nitrocinnamic acid, hydroxycinnamic acid, dihydroxy Cinnamic acid, coumaric acid, phenylpyruvic acid, hydroxyphenylpyruvic acid, caffeic acid, homophthalic acid, tolylacetic acid, phenoxypropionic acid, hydroxyphenylpropionic acid, benzyloxyacetic acid, phenyllactic acid, tropic acid, 3- (phenylsulfonyl) Lopionic acid, 3,3-tetramethylene glutaric acid, 5-oxoazelaic acid, azelaic acid, phenylsuccinic acid, 1,2-phenylenediacetic acid, 1,3-phenylenediacetic acid, 1,4-phenylenediacetic acid, benzyl Malonic acid, sebacic acid, dodecanedioic acid, undecanedioic acid, diphenylacetic acid, benzylic acid, dicyclohexylacetic acid, tetradecanedioic acid, 2,2-diphenylpropionic acid, 3,3-diphenylpropionic acid, 4,4-bis (4 -Hydroxyphenyl) valeric acid, pimaric acid, parastrinic acid, isopimaric acid, abietic acid, dehydroabietic acid, neoabietic acid, agatic acid and the like. Examples of the aromatic carboxylic acid include benzoic acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5- Dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 2,3,4-trihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid, 3,4,5-trihydroxy Benzoic acid, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2- [bis (4-hydroxyphenyl) methyl] benzoic acid, 1- Naphthoic acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 3-hydroxy-2-naphthoic acid, 6- Droxy-2-naphthoic acid, 1,4-dihydroxy-2-naphthoic acid, 3,5-dihydroxy-2-naphthoic acid, 3,7-dihydroxy-2-naphthoic acid, 2,3-naphthalenedicarboxylic acid, 2, Examples include 6-naphthalenedicarboxylic acid, 2-phenoxybenzoic acid, biphenyl-4-carboxylic acid, biphenyl-2-carboxylic acid, and 2-benzoylbenzoic acid. Among these, from the viewpoint of storage stability and availability, succinic acid, malic acid, itaconic acid, 2,2-bis (hydroxymethyl) propionic acid, adipic acid, 3,3′-thiodipropionic acid, 3 , 3′-dithiodipropionic acid, 1,2,3,4-butanetetracarboxylic acid, suberic acid, sebacic acid, phenylsuccinic acid, dodecanedioic acid, diphenylacetic acid, benzylic acid, 4,4-bis (4- Hydroxyphenyl) valeric acid, abietic acid, 2,5-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2- [Bis (4-hydroxyphenyl) methyl] benzoic acid or the like is preferably used. These compounds may be used alone or in combination of two or more.

  The liquid photosensitive adhesive of the present embodiment preferably has a viscosity at 25 ° C. of 10 to 30000 mPa · s, more preferably 30 to 20000 mPa · s from the viewpoint of improving the dischargeability of the adhesive and reducing the film thickness. Preferably, it is further more preferably 50 to 10000 mPa · s, and most preferably 100 to 5000 mPa · s from the viewpoints of heat resistance of the adhesive, adhesiveness after curing, and film thickness uniformity at the time of application. When the viscosity is less than 10 mPa · s, there is a tendency that the storage stability and heat resistance of the adhesive are lowered and pinholes are likely to occur when the adhesive is applied. In addition, it tends to be difficult to make a B stage by exposure. When the viscosity exceeds 30000 mPa · s, there is a tendency that it is difficult to make a thin film at the time of coating, and it is difficult to discharge from the nozzle. The viscosity here is a value of viscosity measured at 25 ° C. under the conditions of a sample volume of 0.4 mL and a 3 ° cone using an EHD type rotational viscometer manufactured by Tokyo Keiki Seisakusho.

  In the liquid photosensitive adhesive of this embodiment, the 5% weight reduction temperature of the adhesive that has been B-staged by light irradiation is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, and 200 ° C. or higher. Most preferably. When the 5% weight reduction temperature is lower than 150 ° C., the adherend tends to peel off at the time of thermosetting after the adherend is bonded or at the time of heat history such as reflow, and heat drying is required before the thermocompression. In addition, from the viewpoints of lowering the adhesive viscosity, suppressing surface irregularities after coating, and thermal fluidity after B-stage, a material design mainly composed of organic compounds is preferable, so the 5% weight loss temperature is 500 ° C. or less. It is preferable that In order to set the 5% weight loss temperature in such a range, the amount of the solvent contained in the adhesive is preferably 5% by mass or less, more preferably 3% by mass or less, and 1% by mass or less. Most preferably it is.

Here, the 5% weight loss temperature is a value measured as follows. A liquid photosensitive adhesive was applied onto a silicon wafer by spin coating so that the film thickness after B-stage was 35 μm, and the resulting coating film was coated with a high-precision parallel exposure machine ((Co., Ltd.) at 25 ° C. under air. ) Exposure is carried out at 1000 mJ / cm ^{2 according} to product name: EXM-1172-B-∞ manufactured by Oak Seisakusho. Thereafter, the B-staged adhesive was measured using a differential thermothermal gravimetric simultaneous measurement device (product name: TG / DTA6300, manufactured by SII Nano Technology Co., Ltd.), with a heating rate of 10 ° C./min, nitrogen flow ( The 5% weight loss temperature is measured under 400 ml / min).

  The liquid photosensitive adhesive of this embodiment preferably has a minimum melt viscosity of 30000 Pa · s or less at 60 ° C. to 200 ° C. after exposure using a high precision parallel exposure machine.

The minimum melt viscosity here is a value obtained by measuring a sample after exposure with a light amount of 1000 mJ / cm ² using a viscoelasticity measuring device ARES (manufactured by Rheometrics Scientific F.E.). The minimum value of melt viscosity at 20 ° C to 300 ° C is shown. The measurement plate is a parallel plate having a diameter of 8 mm, the measurement conditions are a temperature increase of 5 ° C./min, the measurement temperature is 20 ° C. to 300 ° C., and the frequency is 1 Hz.

  The minimum melt viscosity is more preferably 10000 Pa · s or less from the viewpoint of thermocompression bonding, more preferably 5000 Pa · s or less from the viewpoint that thermocompression bonding can be performed when forming a thin film, and thermocompression bonding at a lower temperature and in a shorter time. It is particularly preferable that the pressure is 3000 Pa · s or less. By having the minimum melt viscosity within the above range, sufficient low-temperature thermocompression bonding property can be ensured, and good adhesion can be imparted even to a substrate having irregularities. The lower limit of the minimum melt viscosity is not particularly provided, but is preferably 10 Pa · s or more from the viewpoint of handling property and imparting adhesiveness when heated.

  The liquid photosensitive adhesive of this embodiment is B-staged by light irradiation, and the 5% weight reduction temperature after further heat-curing is 260 ° C. or higher in terms of suppressing peeling due to thermal history. The temperature is preferably 280 ° C. or higher in terms of suppressing voids due to thermal history, and most preferably 300 ° C. or higher from the viewpoint of moisture absorption reflow resistance. If the 5% weight loss temperature is less than 260 ° C., peeling tends to occur due to a thermal history such as a reflow process.

  In addition, the liquid photosensitive adhesive according to the present embodiment can suppress delamination by the amount of outgas when heated in an oven at 140 ° C. for 1 hour and then at 180 ° C. for 3 hours (at the time of heat curing) after the B stage. Is preferably 10% or less, more preferably 7% or less in terms of suppressing voids, and most preferably 5% or less in terms of further suppressing voids and peeling due to thermal history after curing. . When the amount of outgas exceeds 10%, voids and separation tend to occur during heat curing.

The outgas amount here is a value measured as follows. A liquid photosensitive adhesive was applied onto a silicon wafer so that the film thickness after B-stage was 35 μm, and the obtained coating film was laminated with a hand roller at room temperature using a hand-roller. Exposure is performed at 1000 mJ / cm ² with a precision parallel exposure machine. Thereafter, the B-staged adhesive was heated to 140 ° C. at a rate of temperature increase of 50 ° C./min under a nitrogen flow (400 ml / min) using a differential thermothermal gravimetric simultaneous measurement device, and then at 140 ° C. for 1 hour. This is the value of the 5% weight loss temperature when the program is held, further heated to 180 ° C. at a heating rate of 50 ° C./min, and held at 180 ° C. for 3 hours.

  In the liquid photosensitive adhesive of this embodiment, an adhesive layer made of the adhesive is formed on an adherend, and the shear adhesive strength at 260 ° C. at the stage where the semiconductor element is bonded suppresses peeling due to thermal history. In view of the above, it is preferably 0.2 MPa or more, more preferably 0.5 MPa or more, and most preferably 1.0 MPa or more from the viewpoint of moisture absorption reflow resistance. The shear adhesive strength is preferably 50 MPa or less. In order to set the shear bond strength at 260 ° C. to 50 MPa or more, it is necessary to blend a large amount of thermosetting components and inorganic particles, and the film thickness uniformity after coating and the storage stability of the adhesive composition are impaired, In addition, the stress after thermosetting tends to increase.

    The shear adhesive strength here refers to applying a liquid photosensitive adhesive to a thickness of 35 μm on a silicon wafer by spin coating (for example, 2000 rpm / 10 s, 4000 rpm / 20 s). The obtained coating film is laminated with a release-treated PET film and exposed at 1000 mJ / cm 2 with a high-precision parallel exposure machine (“EXM-1172-B-∞” (trade name) manufactured by Oak Seisakusho). Thereafter, a silicon wafer is cut into a 3 × 3 mm square. The cut silicon chip with adhesive is placed on a silicon chip that has been cut into 5 × 5 mm squares, and pressed with pressure of 200 gf for 2 seconds at 120 ° C. Thereafter, it is heated in an oven at 140 ° C. for 1 hour and then at 180 ° C. for 3 hours to obtain an adhesive sample. About the obtained sample, the shear adhesive strength in 260 degreeC was measured using the shear adhesive strength tester "Dage-4000" (product name), and let this be a value of shear adhesive strength.

  The liquid photosensitive adhesive preferably has a visible light transmittance of 10% or more when the adhesive layer is B-staged by light irradiation. If the visible light transmittance is less than 10%, the recognition mark cannot be identified by the flip chip bonder, and there is a tendency that the alignment operation cannot be performed. Moreover, since the wavelength relative intensity of the halogen light source and light guide used in the flip chip bonder is strongest at 550 nm to 600 nm, the liquid photosensitive adhesive may have a visible light transmittance of 550 nm of 10 to 100%. Preferably, it is 18 to 100%, more preferably 25 to 100%.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<Preparation of Liquid Photosensitive Adhesives of Examples 1-3>
Each component was mix | blended with the composition ratio (unit: mass part) shown in following Table 1, and the liquid photosensitive adhesive of Examples 1-3 was obtained.

  The liquid photosensitive adhesive of Example 1 was prepared by the following procedure. First, “M-140” and “AMP-20GY” which are radiation polymerizable compounds, “1032H60” which is an epoxy resin, “I-379EG” and “EAB” which are photoinitiators, and adipine which is a flux component The acid was added and stirred and dispersed using an oil bath at 60 ° C. After returning the obtained mixture to 25 ° C., 1B2PZ as a curing agent and Parkmill D as a thermal radical generator were added and stirred.

  The liquid photosensitive adhesives of Examples 2 and 3 were prepared by the following procedure. First, a filler component was added to “M-140” and “AMP-20GY” which are radiation polymerizable compounds, and the mixture was stirred and dispersed. To the obtained dispersion, add “1032H60” which is an epoxy resin, “I-379EG” and “EAB” which are photoinitiators, and adipic acid which is a flux component, and stir using an oil bath at 60 ° C. , Dispersed. After returning the obtained mixture to 25 ° C., “1B2PZ” which is a curing accelerator and park mill D which is a thermal radical generator were added and stirred.

In Table 1, each symbol means the following.
M-140: manufactured by Toagosei Co., Ltd., 2- (1,2-cyclohexacarboximide) ethyl acrylate (imide functional monofunctional acrylate, 5% weight loss temperature: 200 ° C., viscosity at 25 ° C .: 450 mPa · s) .
AMP-20GY: manufactured by Shin-Nakamura Chemical Co., Ltd., phenoxydiethylene glycol acrylate (monofunctional acrylate, 5% weight loss temperature: 175 ° C., viscosity at 25 ° C .: 16 mPa · s).
I-379EG: Ciba Japan, 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (5% weight loss temperature: 260 ° C., i-ray absorption coefficient: 8000 ml / gcm).
EAB: 4,4′-bisdiethylaminobenzophenone manufactured by Tokyo Chemical Industry Co., Ltd.
1032H60: manufactured by Japan Epoxy Resin Co., Ltd., tris (hydroxyphenyl) methane type solid epoxy resin (5% weight loss temperature: 350 ° C., solid, melting point 60 ° C.).
1B2PZ: 1-benzyl-2-phenylimidazole manufactured by Shikoku Kasei Co., Ltd.
Park mill D: Dicumyl peroxide (manufactured by NOF Corporation, 1 minute half-life temperature: 175 ° C.)
SE1050-SPP: manufactured by Admatechs, phenylsilane surface-treated silica (average particle size: 0.2 to 0.3 μm).
X52-7030: Shin-Etsu Silicone Co., Ltd. silicone composite powder (average particle size: 0.8 μm).
Adipic acid: Wako Pure Chemical Industries, Ltd.

  The viscosity of the component (A) is a value measured at 25 ° C. under the conditions of a sample amount of 0.4 mL and a 3 ° cone using an EHD type rotational viscometer manufactured by Tokyo Keiki Seisakusho.

<Preparation of adhesive for connecting circuit members of Comparative Examples 1 and 2>
(Comparative Examples 1 and 2)
20 parts by mass of a phenoxy resin “FX293” (product name, manufactured by Toto Kasei Co., Ltd.) as a thermoplastic resin, 20 parts by mass of “1032H60” (product name: epoxy equivalent 170, manufactured by Japan Epoxy Resin Co., Ltd.) and “YL” -983U "(manufactured by Japan Epoxy Resin Co., Ltd., product name: epoxy equivalent 184), 10 parts by mass," EXA-4850-1000 "(DIC Corporation, product name: epoxy equivalent 350), 5 parts by mass, microcapsule type curing A mixture obtained by mixing 30 parts by mass of “HX-3941HP” (product name, manufactured by Asahi Kasei Chemicals Corporation) as an accelerator was dissolved in a mixed solvent of toluene and ethyl acetate to obtain a varnish of an adhesive composition. After weighing the resulting varnish, silica particles “SE2050” (manufactured by Admatechs Co., Ltd., product name, average particle size 0.5 μm) as a filler were added in an amount of 75 parts by mass with respect to 85 parts by mass of the varnish. In addition, organic fine particles “EXL-2655” (product name, core shell type organic fine particles, manufactured by Rohm and Haas Japan Co., Ltd.) are added at a ratio of 15 parts by mass with respect to 85 parts by mass of the varnish, and further, a flux component As, 5 parts by weight of “adipic acid” (Wako Pure Chemical Industries, Ltd.) was added, stirred and dispersed. The obtained dispersion was applied on a separator film (PET film, thickness 38 μm) as a supporting substrate using a roll coater, and then dried in an oven at 70 ° C. for 10 minutes. Thus, an adhesive for connecting a circuit member was obtained, in which an adhesive layer having a thickness of 35 μm was formed on the support substrate.

<Preparation of Resin Paste of Comparative Example 3>
(Comparative Example 3)
Phenoxy resin "FX293" (product name, manufactured by Toto Kasei Co., Ltd., product name) 20 parts by mass as a thermoplastic resin, and "1032H60" (product name: epoxy equivalent 170, manufactured by Japan Epoxy Resin Co., Ltd.) 20 masses as an epoxy resin Part, “YL-983U” (manufactured by Japan Epoxy Resin Co., Ltd., product name: epoxy equivalent 184), 10 parts by mass, and “EXA-4850-1000” (manufactured by DIC Corporation, product name: epoxy equivalent 350) 5 As a microcapsule type curing accelerator, a mixture of 30 parts by mass of “HX-3941HP” (product name, manufactured by Asahi Kasei Chemicals Co., Ltd.) is dissolved in a mixed solvent of toluene and ethyl acetate to form an adhesive. A varnish of the composition was obtained. After the obtained varnish was weighed, silica particles “SE2050” (manufactured by Admatechs Co., Ltd., product name, average particle size 0.5 μm) as a filler were added to 75 parts by mass with respect to 85 parts by mass of the varnish. In addition, organic fine particles “EXL-2655” (Rohm and Haas Japan Co., Ltd., product name, core-shell type organic fine particles) were added at a rate of 15 parts by mass with respect to 85 parts by mass of varnish, As a flux component, 5 parts by mass of “adipic acid” (Wako Pure Chemical Industries, Ltd.) was added, stirred and dispersed. Thus, a resin paste was obtained.

  About the liquid photosensitive adhesive of Examples 1-3, the adhesive for circuit member connection of Comparative Examples 1-2, and the resin paste of Comparative Example 3, according to the following method, viscosity, tack after light irradiation, after light irradiation The 5% weight loss temperature, bump voids at the time of forming the adhesive layer, warpage after grinding, visible light transmittance, and connectivity were evaluated. The results are shown in Tables 1 and 2.

<Viscosity>
For the liquid photosensitive adhesives of Examples 1 to 3 and the resin paste of Comparative Example 3, using an EHD type rotational viscometer manufactured by Tokyo Keiki Seisakusho, the sample amount was 0.4 mL, and the condition was 25 ° C. under conditions of 3 ° cone. The viscosity was measured.

<Tack after light irradiation (surface tack force)>
Each of the liquid photosensitive adhesives of Examples 1 to 3 was spin-coated on the circuit surface of a silicon wafer on which metal bumps were formed so that the film thickness after B-stage formation was 35 μm. The obtained coating film was exposed at 1000 mJ / cm ² with a high-precision parallel exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name: EXM-1172-B-∞) at 25 ° C. in the air. Thereafter, using a probe tacking tester manufactured by Reska Co., Ltd., a probe diameter: 5.1 mm, peeling speed: 10 mm / s, contact load: 100 gf / cm ² , contact time: 1 s, adhesive layer at 25 ° C. The surface tack strength was measured 5 times, the average value was calculated, A was 200 gf or less, and B was more than 200 gf.

<5% weight loss temperature after light irradiation>
Each of the liquid photosensitive adhesives of Examples 1 to 3 was spin-coated on the circuit surface of a silicon wafer on which metal bumps were formed so that the film thickness after B-stage formation was 35 μm. The obtained coating film was exposed at 1000 mJ / cm ² with a high-precision parallel exposure machine at 25 ° C. under air. Then, using the differential thermal thermogravimetric simultaneous measuring device (product name: TG / DTA6300, manufactured by SII Nano Technology Co., Ltd.), the obtained adhesive was heated at a rate of 10 ° C./min and nitrogen flow (400 ml). The 5% weight loss temperature was measured under

  The silicon wafer used for the evaluation is a wafer with protruding electrodes having a configuration in which copper bumps are formed on the wafer and solder balls are further placed thereon. Specifically, an 8-inch size (thickness: 725 μm), with a bump having a structure having a lead-free solder layer (Sn-3.5Ag: melting point 221 ° C.) at the tip of the copper pillar, manufactured by Hitachi VLSI Systems, JTEG PHASE11_80 (size 7.3 mm × 7.3 mm, bump pitch 80 μm, copper bump 20 μm, lead-free solder 20 μm, bump number 328, thickness 0.55 mm, product name) was used.

<Void when forming adhesive layer>
For Examples 1 to 3, the adhesive was spin-coated on the circuit surface of the silicon wafer so as to have a film thickness of 35 μm, and a high-precision parallel exposure machine (Oak Manufacturing Co., Ltd.) at 25 ° C. in the air. (Product name: EXM-1172-B-∞) manufactured by the company, exposure was performed at 1000 mJ / cm ² . In Comparative Example 1, an adhesive for connecting circuit members was attached on the circuit surface of the silicon wafer using a laminator at 80 ° C., a linear pressure of 1.0 kgf / cm, and a feed rate of 0.5 mm / min. In Comparative Example 2, the adhesive for connecting circuit members was placed on the circuit surface of the silicon wafer using a vacuum laminator (product name: V130 manufactured by Nichigo Morton Co., Ltd.), stage temperature 40 ° C., diaphragm temperature 80 The paste was applied under the conditions of C, degassing time 20 seconds, pressurization time 20 seconds, and pressurization 0.5 MPa. In Comparative Example 3, the resin paste was spin-coated on the circuit surface of the silicon wafer so that the film thickness after heating and drying was 35 μm, and dried on a hot plate at 70 ° C. for 10 minutes.

The voids around the protruding electrode on which the adhesive layer was formed were confirmed visually and with a microscope and evaluated according to the following criteria.
A: There is no void around the bump.
B: A small amount of void exists around the bump.
C: A large amount of voids exist around the bumps.

<Warpage after grinding>
The following back grind tape A is pasted on a 6-inch wafer (thickness: 625 μm) on which an adhesive layer has been formed in the same manner as described above, and thickened with a back grinder (manufactured by Disco Corporation, product name: DBG8540). Grinded to a thickness of 50 μm. The ground wafer was placed on a flat table, the height at which the wafer was most warped was measured, and evaluated according to the following criteria.
A: The warpage of the wafer was less than 10 mm.
B: The warpage of the wafer was 10 mm or more.

(Back grind tape A)
An acrylic copolymer using 2-ethylhexyl acrylate and methyl methacrylate as main monomers and hydroxyethyl acrylate and acrylic acid as functional group monomers was obtained by a solution polymerization method. The synthesized acrylic copolymer had a weight average molecular weight of 400,000 and a glass transition point of -38 ° C. A pressure-sensitive adhesive solution containing 10 parts by mass of a polyfunctional isocyanate cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., product name: Coronate HL) was prepared with respect to 100 parts by mass of this acrylic copolymer, and a polyolefin film (thickness) 150 μm) and dried so that the thickness of the pressure-sensitive adhesive when dried was 10 μm. Further, a biaxially stretched polyester film separator (thickness 25 μm) coated with a silicone release agent was laminated on the pressure-sensitive adhesive surface. The pressure-sensitive adhesive film was allowed to stand at room temperature for 1 week and sufficiently aged. This was used as a back grind tape A in the test.

<Visible light transmission>
Each of the liquid photosensitive adhesives of Examples 1 to 3 was applied on a PET (polyethylene terephthalate) film so as to have a film thickness of 35 μm, and this coating film was 1000 mJ with a high-precision parallel exposure machine at 25 ° C. under air. A film for measurement was obtained by exposure at / cm ² . The obtained film for measurement was peeled off from PET, and the transmittance at 555 nm was measured using a spectrophotometer (manufactured by Hitachi High-Technologies Corporation, product name: U-3310). A having a transmittance of 10% or more was designated as A, and B being less than 10%.

  About the adhesive for circuit member connection of Comparative Examples 1-2, the support base material was peeled and visible light transmittance | permeability was evaluated similarly to the above. About the resin paste of the comparative example 3, the resin paste was apply | coated so that it might become a film thickness of 35 micrometers on a PET (polyethylene terephthalate) film | membrane, and it was made to dry for 10 minutes with a 70 degreeC hotplate, and the film for a measurement was obtained. The obtained film for measurement was peeled from PET, and the visible light transmittance was evaluated in the same manner as described above.

<Connectivity>
A support member for mounting a semiconductor element was prepared by applying SR-AUS308 to the pattern surface of a glass epoxy substrate having a copper wiring pattern having a rust preventive film formed thereon by preflux treatment.

  In Examples 1 to 3 and Comparative Example 3, a wafer with an adhesive layer was prepared in the same manner as in the evaluation of “Void at the time of forming an adhesive layer”, and this was diced into 7.3 mm × 7.3 mm according to a dicing line. Thus, a semiconductor chip with an adhesive layer was obtained. Next, as a first step, flip chip bonder (manufactured by Panasonic Factory Solutions Co., Ltd., product name) so that the temperature of the connecting portion is 180 ° C. which is higher than the melting point of the solid flux agent and lower than the melting point of lead-free solder. FCB3) head temperature was set (stage temperature: 40 ° C.), and the semiconductor element mounting support member and the semiconductor chip with an adhesive layer were pressure-bonded at a load of 25 N for 10 seconds. Next, as the second step, the head temperature of the flip chip bonder was set so that the temperature of the connecting portion was 250 ° C. higher than the melting point of the lead-free solder, and a pressure was applied at 25 N for 10 seconds to prepare a sample. The temperature of the connection portion was measured by separately manufacturing a K-type thermocouple sandwiched between the semiconductor chip and the substrate.

  In Comparative Examples 1 and 2, the adhesive for connecting circuit members was cut out to 9 mm × 9 mm and pasted on the region where the semiconductor chip of the semiconductor element mounting support member is mounted under the condition of 80 ° C./0.5 MPa / 5 seconds. After that, the support film was peeled off. The substrate on which the circuit member connecting adhesive was adhered and the semiconductor chip were pressure-bonded with a flip chip bonder at a load of 25 N and a temperature of 100 ° C. for 5 seconds to temporarily fix the semiconductor chip on the substrate. Next, the same operation as in the first step and the second step was performed to prepare a sample.

About the sample after crimping | bonding, the conduction | electrical_connection by the daisy chain connection of 328 bump was confirmed, and the connectivity was evaluated by the following criteria.
A: Conductivity was confirmed.
B: A location with poor conduction was present.

DESCRIPTION OF SYMBOLS 4 ... Adhesive tape, 5 ... Liquid photosensitive adhesive, 6, 6a, 6b ... Adhesive layer, 9 ... Exposure apparatus, 10 ... Semiconductor wafer, 10a ... Semiconductor chip, 12 ... Metal bump, 14 ... Solder ball, 15 ... Support member, 30 ... Adhesive tape (back grind tape), 34 ... Grinding device, 36 ... Adhesive tape (dicing tape), 40 ... Semiconductor element with adhesive layer, 54 ... Semiconductor wafer, 70 ... Semiconductor wafer with semiconductor element, 80 , 100, 110... Semiconductor devices.

Claims (4)

A liquid photosensitive adhesive for forming a photosensitive adhesive layer on the circuit surface of a semiconductor wafer having a circuit surface on which metal bumps are formed,
(A) a radiation polymerizable compound, (B) a photoinitiator, and (C) a thermosetting resin,
The liquid photosensitive adhesive in which the said (A) component contains the imide group containing (meth) acrylate which has one carbon-carbon double bond in a molecule | numerator. Applying a liquid photosensitive adhesive to form a photosensitive adhesive layer on the circuit surface of the semiconductor wafer having a circuit surface on which metal bumps are formed;
Forming the photosensitive adhesive layer into a B-stage by light irradiation to obtain a semiconductor wafer with an adhesive layer;
Cutting the semiconductor wafer of the semiconductor wafer with the adhesive layer together with the adhesive layer and cutting it into a plurality of semiconductor elements to obtain a semiconductor element with the adhesive layer;
A step of crimping the semiconductor element with an adhesive layer and another semiconductor element or a semiconductor element mounting support member with the adhesive layer of the semiconductor element with the adhesive layer sandwiched therebetween, . Applying a liquid photosensitive adhesive to form a photosensitive adhesive layer on the circuit surface of the semiconductor wafer having a circuit surface on which metal bumps are formed;
Forming the photosensitive adhesive layer into a B-stage by light irradiation to obtain a semiconductor wafer with an adhesive layer;
Cutting the semiconductor wafer of the semiconductor wafer with the adhesive layer together with the adhesive layer and cutting it into a plurality of semiconductor elements to obtain a semiconductor element with the adhesive layer;
A method of manufacturing a semiconductor wafer with a semiconductor element, comprising: a second semiconductor wafer and a step of pressure-bonding the semiconductor element with an adhesive layer with the adhesive layer of the semiconductor element with an adhesive layer interposed therebetween. Applying a liquid photosensitive adhesive to form a photosensitive adhesive layer on the circuit surface of the semiconductor wafer having a circuit surface on which metal bumps are formed;
And a step of converting the photosensitive adhesive layer into a B-stage by light irradiation. A method for producing a semiconductor wafer with an adhesive layer.

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