JP3872466B2 - Semiconductor device, method for manufacturing the same, and display device - Google Patents

Description

  The present invention relates to a semiconductor device having a structure in which a semiconductor element is incorporated into a flexible tape base material on which a metal thin film wiring layer is formed, and more particularly to a semiconductor device with improved bendability and a method for manufacturing the same.

  In a thin display device typified by a liquid crystal display, a driving semiconductor device for inputting a display signal is used. There is a strong demand for such a semiconductor device such as thinness and multiple outputs, and a tape carrier package (hereinafter referred to as TCP) corresponding to this is conventionally known. Among them, as shown in FIGS. 11 and 12, there are no device holes or bending slits, and the inner leads 4 a connected to the metal protrusions 6 formed on the metal electrodes 8 of the semiconductor element 5 are in close contact with the film substrate 2. What is known is a TCP having a chip-on-film (hereinafter referred to as COF) structure (see, for example, Patent Document 1).

  Since the COF has no device hole and the inner lead 4a is in close contact with the film base 2, there is no flying lead that tends to bend, and the conductor lead 4 can be made thin. Thereby, the etching property of the conductor lead 4 is improved and a finer conductor pattern 4 can be formed as compared with the conventional TCP having a device hole. Further, by reducing the thickness of the film substrate 2, it can be easily bent without forming a slit (through hole).

  Hereinafter, an example of a conventional semiconductor device having a general COF structure will be described with reference to FIGS. FIG. 11 is a plan view of a semiconductor device having a COF structure. 12 is a cross-sectional view taken along the line F-F ′ of FIG. 11. FIG. 13 is an enlarged view of part G in FIG.

  The film carrier 1 is composed of a film base 2 formed of a resin such as polyimide having insulation and flexibility, and a conductor lead 4 formed of a metal foil such as copper. A region of the conductor lead 4 that is not covered with the solder resist 3 from the tip of the portion connected to the metal electrode 8 of the semiconductor element 5 to the periphery of the solder resist 3 is referred to as an inner lead 4a. Of the conductor leads 4 extended on the film base 2 outward from the inner leads 4a, the region connected to the external circuit is called an outer lead 4b. The conductor lead 4 is usually plated. On the metal electrode 8 of the semiconductor element 5, a metal protrusion 6 for connecting to the inner lead 4a is formed. The height of the metal protrusion 6 varies, and there is a configuration without the metal protrusion 6. The region around the inner lead 4a is covered with a sealing resin 7 for protecting the surface of the semiconductor element 5 and ensuring the strength of the semiconductor device itself. As shown in FIG. 13, the sealing resin 7 forms a resin fillet 7a between the side surface of the semiconductor element 5 and the film carrier 1 positioned perpendicular to the side surface by the surface tension.

  A conventional mounting state of a COF type driving semiconductor device will be described by taking as an example a liquid crystal display on which the semiconductor device having the above configuration is mounted. FIG. 14 is a cross-sectional view of a state in which a driving semiconductor device and a PCB substrate 14 for power supply / signal supply are mounted on a conventional general liquid crystal display. The liquid crystal panel has a structure in which a glass substrate 11 and a display glass 9 are bonded together, and a backlight 10 is disposed on the back surface of the glass substrate 11. The glass substrate 11 is provided with a semiconductor device mounting region protruding from the display glass 9. A transparent electrode 12 is formed in the mounting area. On the back surface of the glass substrate 11, a PCB substrate 14 for supplying power and signals is disposed adjacent to the backlight 10. The output outer leads 4b-b of the COF type semiconductor device are connected via an anisotropic conductive film 13 on the transparent electrode 12 formed at the end of the glass substrate 11. On the other hand, the input outer lead 4b-a bends the film base 2 and winds the end of the glass substrate 11 and folds it back to the back surface of the liquid crystal display. Connected through. As described above, the semiconductor device is mounted on the device in a bent state by taking advantage of the flexibility provided by the film carrier 1.

  Next, referring to FIG. 15, a general method is used in which the metal protrusion 6 formed on the inner lead 4a of the film carrier 1 and the metal electrode 8 of the semiconductor element 5 is bonded by intermetallic bonding such as eutectic. The assembly process of the COF will be described.

  As shown in FIG. 15A, the inner lead 4 a of the film carrier 1 is formed on the film base 2 in accordance with the position of the metal protrusion 6 of the semiconductor element 5. The surface of the inner lead 4a is plated with tin or gold. The film substrate 2 has a thickness of 38 μm, 25 μm, etc., and is considerably thinner than the conventional general TCP thickness of 75 μm. The metal protrusion 6 of the semiconductor element 5 is disposed along the outer periphery of the semiconductor element 5 or on the entire surface of the semiconductor element 5. The metal protrusion 6 has a height of about 10 μm to 30 μm, which is equivalent to that used in the conventional TCP.

  As shown in FIG. 15B, the metal protrusion 6 on the semiconductor element 5 and the inner lead 4a of the film carrier 1 are aligned in a predetermined state and bonded by a thermocompression bonding method. With the thermocompression bonding method, while applying a temperature (about 300 ° C. to 500 ° C.) and a load necessary for eutectic fusion or solid phase diffusion of the plating material applied to the inner lead 4a and the material of the metal protrusion 6, In this method, the inner lead 4a and the metal protrusion 6 are joined. The film is pressed from the film base 2 side by the bonding tool 16 and the semiconductor element 5 side is supported by the chip stage 17.

  After the thermocompression bonding, as shown in FIG. 15C, the sealing resin 7 is injected into the gap between the film carrier 1 and the semiconductor element 5 using the resin supply nozzle 18. This protects the joint portion between the inner lead 4a and the metal protrusion 6 and the surface portion where the circuit of the semiconductor element 5 exists, and ensures the mechanical strength of the entire semiconductor device. At this time, an appropriate amount of the sealing resin 7 can be supplied to the whole by discharging the sealing resin 7 while drawing a locus on the outer periphery of the semiconductor element 5 by the resin supply nozzle 18. The liquid sealing resin 7 is formed on the side surface when the circuit formation surface of the semiconductor element 5 is a main surface, the surface on which the semiconductor element 5 of the film carrier 1 is mounted, the side surface of the semiconductor element 5 and the surface of the film carrier 1. The resin fillet 7-a (see FIG. 13) is formed with the surface tension for each. After sealing, stamping and inspection are performed to complete the COF product.

The step of joining the inner lead 4a and the metal protrusion 6 is called an ILB (inner lead bonding) step, and the step of sealing the inner lead 4a and the surface of the semiconductor element 5 with the sealing resin 7 is called a sealing step.
JP 2001-203302 A

  As shown in FIG. 14, when a semiconductor device having a COF structure is mounted, the outer lead 4b-b on the output side is connected to the surface of the glass substrate 11, and the film carrier 1 (see FIG. 12) is bent to display. In the display device having a structure in which the input outer lead 4b-a is connected to the PCB substrate 14 by winding the end surface of the film and connecting the input outer lead 4b-a to the PCB substrate 14, the length of the film carrier 1 to be bent is large and the film cost increases. is there.

  Therefore, the film carrier 1 is efficiently used by being bent as close to the side surface of the glass substrate 11 as possible. At this time, the film carrier 1 is strongly bent at the end of the glass substrate 11. When the periphery of the sealing resin 7 is close to the bent portion, a sharp change in the bending curvature is caused by the difference in elastic modulus due to the presence or absence of the sealing resin 7 at the edge of the sealing resin 7. A point is formed. There is an example in which the transparent electrode 12 of the glass substrate 11 is bent at 90 degrees or more from the portion where the semiconductor element 5 is disposed. A sudden change in the curvature may damage the conductor lead 4 and eventually lead to the occurrence of disconnection.

In the semiconductor device according to the present invention, a semiconductor element is mounted on a flexible tape base material on which conductor leads are formed, and a sealing resin is filled in a gap between the tape base material and the semiconductor element. A resin fillet is formed by the sealing resin on the side surface of the main surface that is the formation surface and on the semiconductor element mounting surface of the tape base material. In order to solve the above problems , a solder resist is formed on the tape base material, and the portion of the resin fillet formed on the solder resist is continuously reduced in thickness in a direction away from the semiconductor element. It has the resin thin film area | region which does not carry out.

  According to the said structure, a softness | flexibility with respect to the bending of the thickness direction can be ensured by providing the resin thin film area | region. Thereby, when the semiconductor device is bent and mounted, a sudden change in the bending curvature that occurs at the outer end of the sealing resin can be suppressed, and problems such as disconnection of the wiring can be prevented.

  In the semiconductor device of the present invention, the resin thin film region may be formed only on part of the outer periphery of the four sides of the semiconductor element.

Moreover, it is preferable that the resin thin film region is formed so as to cover the entire region where the tape base material is bent to form a curvature in a state where the tape substrate is bent and mounted on the display device.
Further, in the semiconductor device of another configuration of the present invention, a semiconductor element is mounted on a flexible tape substrate on which conductor leads are formed, and a sealing resin is filled in a gap between the tape substrate and the semiconductor element. The semiconductor element has a configuration in which a resin fillet is formed of the sealing resin on a side surface of the semiconductor element with respect to a main surface which is a circuit forming surface and on the semiconductor element mounting surface of the tape base material. A resin thin film formed of a resin different from the sealing resin extending from the front end of the resin fillet on the solder resist, the resist having a thickness that does not continuously decrease in a direction away from the semiconductor element. It has a region.

In the method of manufacturing a semiconductor device according to the present invention, in order to manufacture the semiconductor device having the above configuration, after forming the conductor leads on the tape base material, a solder resist is formed, and the semiconductor element is formed on the solder resist. Forming a resin thin film region in which the thickness does not continuously decrease toward the direction away from the semiconductor substrate, then mounting the semiconductor element on the tape base material and overlapping the end of the resin thin film region The sealing resin is filled.

  A display device comprising the semiconductor device having any one of the above configurations, wherein the semiconductor device is mounted in a state where both the tape base material and the resin layer of the resin thin film region formed on the surface of the tape base material are curved. Can be configured.

  Hereinafter, a semiconductor device and a manufacturing method thereof according to embodiments of the present invention will be specifically described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a plan view of a semiconductor device having a COF structure according to the first embodiment. 2 is a cross-sectional view taken along the line AA ′ of FIG. FIG. 3 is an enlarged view of part B of FIG.

  The film carrier 1 is composed of a film base 2 formed of an insulating and flexible resin such as polyimide, and conductor leads 4 formed of a metal foil such as copper on the film base 2. Yes. The upper surface of the film carrier 1 is covered with the solder resist 3 leaving a partial area. A semiconductor element 5 is mounted in a region not covered with the solder resist 3 in the center, and the metal electrode 8 of the semiconductor element 5 is connected to the conductor lead 4. The conductor lead 4 is an area not covered by the solder resist 3, an inner lead 4 a from the tip of the portion connected to the metal electrode 8 of the semiconductor element 5 to the inner edge of the solder resist 3, and an outer side from the inner lead 4 a. Of the conductor leads 4 extended in the direction, the outer leads 4b are exposed from the outer edge of the solder resist 3 and connected to an external circuit.

  The conductor lead 4 is usually plated. On the metal electrode 8 of the semiconductor element 5, a metal protrusion 6 necessary for connecting the metal electrode 8 and the inner lead 4 a is formed. The height of the metal protrusion 6 varies, and the metal protrusion 6 may not be provided. The region around the inner lead 4a is covered with a sealing resin 7 for protecting the surface of the semiconductor element 5 and ensuring the strength of the semiconductor device itself. As shown in FIG. 3, the sealing resin 7 forms a resin fillet 7 a between the side surface of the semiconductor element 5 and the film carrier 1 positioned perpendicular to the side surface due to surface tension.

  The resin fillet 7a forms a resin thin film region 7b having a constant thickness of the sealing resin 7 at the end thereof. That is, the resin thin film region 7b has a substantially constant thickness of a certain level or less without continuously decreasing the resin thickness. The resin thin film region 7b is formed by maintaining a substantially constant thin film resin thickness 19 mainly on the formation region of the solder resist 3 as a cross-sectional structure. The planar configuration is formed along the outer periphery of the four sides of the semiconductor element 5 as shown in FIG.

  The resin thin film region 7b remains elastic because of its thinness even after the resin is cured, and is flexible with respect to bending in the thickness direction. Therefore, when the semiconductor device is bent and mounted, it is possible to suppress the occurrence of a sudden change point of the bending curvature due to the presence or absence of the sealing resin 7 at the outer end of the sealing resin 7. That is, since the resin thin film region 7b bends flexibly, the film carrier 1 is not locally bent sharply at the outer end of the sealing resin 7. Therefore, it is possible to prevent problems such as disconnection of wiring.

  If the resin thickness in the resin thin film region 7b is in the range of 1 μm to 10 μm, a practically sufficient effect can be obtained.

  FIG. 4 is a sectional view showing a state in which the semiconductor device of the present embodiment and the PCB substrate 14 for power supply / signal supply are mounted on a general liquid crystal display. The liquid crystal panel has a structure in which a glass substrate 11 and a display glass 9 are bonded together, and a backlight 10 is disposed on the back surface of the glass substrate 11. The glass substrate 11 has a semiconductor device mounting region protruding from the display glass 9, and a transparent electrode 12 is formed thereon. On the back surface of the glass substrate 11, a PCB substrate 14 for supplying power and signals is disposed adjacent to the backlight 10.

  The output outer leads 4b-b of the COF type semiconductor device are connected via an anisotropic conductive film 13 on the transparent electrode 12 formed at the end of the glass substrate 11. On the other hand, the input outer lead 4b-a bends the film base 2 and winds the end of the glass substrate 11 and folds it back to the back surface of the liquid crystal display. Connected through. As described above, the semiconductor device is mounted on the device in a bent state by taking advantage of the flexibility provided by the film carrier 1.

  In the semiconductor device of the present embodiment, the resin thin film region 7b of the sealing resin 7 is a film at the bent portion of the film carrier 1 from the transparent electrode 12 on the surface of the glass substrate 11 to the portion where the semiconductor element 5 is disposed. The carrier 1 has a structure that bends along the bending curvature of the carrier 1. Therefore, it is possible to suppress a sudden change in the bending curvature, and to obtain a gentle bending shape as a whole.

  Further, also in the bent portion from the PCB substrate 14 located on the back surface of the glass substrate 11 to the portion where the semiconductor element 5 is arranged, the resin thin film region 7b of the sealing resin 7 is in a form along the bending curvature of the film carrier 1. The structure may be bent. In addition, the resin thin film region 7b is formed regardless of the bending curvature of the film carrier 1 and for bending other than the cross section shown in FIG. 4, and the resin thin film region 7b follows the curvature of the film carrier 1. You may make it bend.

(Embodiment 2)
The semiconductor device in Embodiment 2 will be described with reference to FIGS. The basic configuration of the semiconductor device is the same as that of the first embodiment, and the planar shape is slightly different. The cross section along the line CC ′ in FIG. 5 and the line DD ′ in FIG. 6 is the same as that in FIG. 2 except for a part, so the cross sectional shape will be described with reference to FIGS. To do. The same elements are denoted by the same reference numerals to simplify the description.

  In the planar shape of the resin fillet 7 a in the configuration of FIG. 5, the resin thin film region 7 b is not formed over the entire outer periphery of the four sides of the semiconductor element 5. In the configuration of FIG. 5, resin thin film regions 7 b are formed only at four corner portions in the planar shape of the semiconductor element 5. When this semiconductor device is bent and mounted on a liquid crystal display in the same manner as in the first embodiment, the resin thin film region 7b is bent along the curvature of the film carrier 1 as in the first embodiment. Therefore, when this semiconductor device is bent and mounted on a liquid crystal display, the occurrence of a sharp change point of curvature is suppressed as in FIG.

  Further, as shown in FIGS. 6 and 7, the resin thin film region 7 b may be formed along only one side of the semiconductor element 5. That is, the resin thin film region 7b is formed only on the side where the bending curvature of the film carrier 1 is smaller and the degree of bending is higher when the semiconductor device is mounted with the liquid crystal display folded. As a result, the function of suppressing a rapid change in curvature is exhibited in the main region, so that a practically sufficient effect can be obtained.

(Embodiment 3)
A semiconductor device in Embodiment 3 will be described with reference to FIG. FIG. 8 is an enlarged view of a portion E in FIG. In the present embodiment, the range in which the resin thin film region 7b is to be formed is specified.

  Although the film carrier 1 is bent and the resin thin film region 7b is also bent along this, a rapid change in curvature is suppressed, but at the boundary between the thin film region 7b and the region where the sealing resin 7 is not attached, The bending curvature of the film carrier 1 may suddenly change due to the bending elastic force that tends to repel the bending of the sealing resin 7.

 On the other hand, by forming the resin thin film region 7b so as to cover all the regions where the film carrier 1 is bent to form the curvature, it is possible to avoid the occurrence of a sudden change point of the bending curvature. For example, in the bent state as shown in FIG. 8, the width W μm of the resin thin film region 7b required in this configuration, the bending curvature R μm of the film carrier 1 in the bent state, and the bending angle α ° of the film carrier 1 The following relationship holds.

W μm ≧ (α ° / 360 °) × (2 × R μm) π π: Circumferential ratio If the resin thin film region 7b is provided according to this equation, the film carrier in the laminated structure composed of the film carrier 1 and the resin thin film region 7b It is possible to avoid the occurrence of a sharp curvature change point in which stress concentrates on one bent portion.

(Embodiment 4)
A semiconductor device in Embodiment 4 will be described with reference to FIG. FIG. 9 is an enlarged view of a portion corresponding to portion B in FIG. The basic configuration of the semiconductor device is the same as that of the first embodiment.

  In this embodiment, before the resin fillet 7a is formed by the sealing resin 7, the pre-formed resin thin film region is formed on the solder resist 3 in the region where the resin thin film region 7b in each of the above embodiments is formed. 20 is formed. By forming the pre-formed resin thin film region 20 separately from the resin fillet 7a, resins having different physical properties can be used. Therefore, it is possible to improve the degree of freedom of the process, such as selection of resin physical properties dedicated to the resin thin film region and setting of dedicated liquid resin application conditions, and to form the resin thin film region stably and accurately.

(Embodiment 5)
A semiconductor device in Embodiment 5 will be described with reference to FIG. FIG. 10 is a cross-sectional view showing an example of the film carrier 1 used in the semiconductor device of FIG.

  In the present embodiment, the pre-formed resin thin film region 20 in the fourth embodiment is formed not in the semiconductor device assembly step but in the manufacturing process of the film carrier 1. In the film carrier 1 shown in FIG. 10, the conductor leads 4 are formed on the surface of the film base 2, and the surface of the necessary parts is protected with the solder resist 3, and then the resin or the resin is formed in a desired region corresponding to the outer periphery of the semiconductor element. The pre-formed resin thin film region 20 is formed by a tape or the like.

  Thereby, in the sealing process of the semiconductor device, it is not necessary to form the resin thin film region 7b with the sealing resin 7, and the sealing process is simplified as compared with the case where the resin thin film region 7b is formed in the sealing process. Is done. Moreover, since the element of thin film formation property can be suppressed also about the resin material, the freedom degree of material selection can be improved. The material and configuration of the pre-formed resin thin film region 20 have a bending elastic force located between the bending elastic force of the film carrier 1 and the bending elastic force of the sealing resin 7 in a state completed as a semiconductor device. Consideration is made so that when the carrier 1 is bent, it is continuously bent and a sharp change point does not occur in the curvature.

  The semiconductor device of the present invention suppresses a sudden change in the bending curvature that occurs at the outer end of the sealing resin when mounted by bending, and can prevent the occurrence of wire breakage, It is suitable as a semiconductor device used for a display device typified by a liquid crystal display.

Plan view showing the semiconductor device in the first embodiment Sectional view along the line AA 'in FIG. Enlarged sectional view of part B in FIG. Sectional drawing which shows the liquid crystal display with which the semiconductor device in Embodiment 1 was mounted A plan view showing a semiconductor device in a second embodiment FIG. 7 is a plan view illustrating another example of the semiconductor device in Embodiment 2. Sectional drawing which shows the liquid crystal display with which the semiconductor device of FIG. 6 was mounted. The expanded sectional view of the part corresponding to the E section of Drawing 4 of the semiconductor device in Embodiment 3. The expanded sectional view of the part corresponding to the B section of Drawing 2 of a semiconductor device in Embodiment 4. Sectional drawing which shows the film carrier used for the semiconductor device in Embodiment 5 Plan view showing a conventional semiconductor device having a COF structure Sectional view along line FF 'in FIG. FIG. 12 is an enlarged sectional view of a portion G. Sectional drawing which shows the liquid crystal display with which the semiconductor device of FIG. 11 was mounted. Sectional drawing which shows the manufacturing method of the semiconductor device of the COF structure of a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film carrier 2 Film base material 3 Solder resist 4 Conductor lead 4a Inner lead 4b Outer lead 4b-a Input outer lead 4b-b Output outer lead 5 Semiconductor device 6 Metal protrusion 7 Sealing resin 7a Resin fillet 7b Resin thin film area 8 Metal Electrode 9 Display glass 10 Backlight 11 Glass substrate 12 Transparent electrode 13 Anisotropic conductive film 14 PCB substrate 15 Electrode 16 Bonding tool 17 Chip stage 18 Resin supply nozzle 19 Thin film resin thickness 20 Preformed resin thin film area W Thin film resin width R Resin Bending curvature α of thin film region Film folding angle

Claims (6)

A semiconductor element is mounted on a flexible tape base material on which a conductor lead is formed, and a sealing resin is filled in a gap between the tape base material and the semiconductor element. In the semiconductor device having a configuration in which a resin fillet is formed of the sealing resin on the side and the semiconductor element mounting surface of the tape base material,
A solder resist is formed on the tape base material, and a portion of the resin fillet formed on the solder resist has a resin thin film region in which a thickness does not continuously decrease in a direction away from the semiconductor element. A featured semiconductor device.   The semiconductor device according to claim 1, wherein the resin thin film region is formed only at a part of an outer periphery of four sides of the semiconductor element.   3. The semiconductor device according to claim 1, wherein the resin thin film region is formed so as to cover the entire region where the tape base material is bent to form a curvature in a state where the tape substrate is bent and mounted on the display device. A semiconductor element is mounted on a flexible tape base material on which a conductor lead is formed, and a sealing resin is filled in a gap between the tape base material and the semiconductor element. In the semiconductor device having a configuration in which a resin fillet is formed of the sealing resin on the side and the semiconductor element mounting surface of the tape base material,
A solder resist is formed on the tape base material, and the thickness is formed in a direction away from the semiconductor element, which is formed of a resin different from the sealing resin extending on the solder resist from the tip of the resin fillet. A semiconductor device having a resin thin film region which does not continuously decrease . After the semiconductor element is mounted on the flexible tape base material on which the conductor leads are formed, the gap between the tape base material and the semiconductor element is filled with a sealing resin, and the main surface that is the circuit forming surface of the semiconductor element In the method for manufacturing a semiconductor device, in which a resin fillet is formed with the sealing resin on the side surface and the semiconductor element mounting surface of the tape base material,
After forming the conductor lead on the tape substrate, forming a solder resist , on the solder resist, forming a resin thin film region in which the thickness does not continuously decrease toward the direction away from the semiconductor element ,
Thereafter, the semiconductor element is mounted on the tape base material, and the sealing resin is filled so as to have an overlap with an end portion of the resin thin film region .   5. The semiconductor device according to claim 1, wherein the tape substrate and the resin layer in the resin thin film region formed on the surface of the tape substrate are both curved. Display device implemented in the state.

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