JP2015129226A - Film type adhesive, dicing tape with film type adhesive, method for manufacturing semiconductor device, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film type adhesive capable of reducing a stress caused by a difference in linear thermal expansion, a dicing tape with a film type adhesive, and a method for manufacturing a semiconductor device.SOLUTION: A thermosetting film type adhesive 3 comprises an acrylic resin, an epoxy resin, and conductive particles. The conductive particles include plate type particles having an aspect ratio of 5 or more; and the content of the plate type conductive particles is 5 wt.% to 100 wt.% in 100 wt.% of the conductive particles. The adhesive after being thermally cured shows a storage modulus of 5 MPa to 100 MPa at 150°C.

Description

The present invention relates to a film adhesive, a dicing tape with a film adhesive, a method for manufacturing a semiconductor device, and a semiconductor device.

In the manufacture of semiconductor devices, a method of bonding a semiconductor element to a metal lead frame or the like (so-called die bonding method) has been changed from a conventional gold-silicon eutectic method to a solder or resin paste method. At present, a method using a conductive resin paste is used.

However, the method using a resin paste has a problem that the conductivity is reduced by voids, the thickness of the resin paste is non-uniform, and the pad is contaminated by the protrusion of the resin paste. In order to solve these problems, a film-like adhesive containing a polyimide resin may be used instead of the resin paste (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 6-145639

By the way, in a semiconductor device, reliability is important. Examples of the test for evaluating reliability include a temperature cycle test, a pressure cooker test, and a moisture absorption reflow test.

In recent years, many thin semiconductor devices are mounted on smartphones and laptop computers in order to achieve both performance improvement and thinning of devices. However, the thinner the semiconductor device, the greater the influence of stress generated by the difference in linear expansion between the silicon chip and the metal lead frame in the temperature cycle test, and the failure of the adhesive joining the silicon chip and the metal lead frame increases. .

An object of the present invention is to solve the above-mentioned problems and to provide a film adhesive, a dicing tape with a film adhesive, and a method for manufacturing a semiconductor device that can relieve stress caused by a difference in linear expansion. .

The present invention includes an acrylic resin, an epoxy resin, and conductive particles. The conductive particles include plate-like particles having an aspect ratio of 5 or more, and the content of the plate-like particles in 100% by weight of the conductive particles is 5%. It relates to a thermosetting film-like adhesive having a storage elastic modulus at 150 ° C. of 5 to 100 MPa after thermosetting.

Since the film-like adhesive of the present invention has a storage elastic modulus at 150 ° C. after thermosetting of 100 MPa or less, it is possible to relieve the stress caused by the difference in linear expansion and reduce defects in the temperature cycle test. . Further, since the plate-like particles having an aspect ratio of 5 or more are included, it is possible to form a conductive path by surface contact between the plate-like particles. For this reason, compared with the adhesive agent which contains only the spherical particle in which a conductive path is formed by point contact, the electroconductivity excellent in the film adhesive of this invention is acquired.

An epoxy resin having a bisphenol type skeleton is preferable because the distance between the epoxy groups is long and the storage elastic modulus after thermosetting can be reduced. The epoxy equivalent of the epoxy resin is 180 g / eq. ~ 3500 g / eq. It is preferable that

The film adhesive of the present invention further contains a phenol resin, and the hydroxyl equivalent of the phenol resin is 200 g / eq. The above is preferable. Thereby, the storage elastic modulus after thermosetting can be reduced easily.

The film adhesive of the present invention preferably contains a high molecular weight acrylic resin having a weight average molecular weight of 200,000 to 1,000,000. Thereby, the storage elastic modulus after thermosetting can be reduced.

It is preferable that the film adhesive of this invention contains the low molecular weight acrylic resin containing the functional group which reacts with an epoxy group. The low molecular weight acrylic resin preferably has a weight average molecular weight of 500 to 100,000. This is because the low molecular weight acrylic resin can be cured and the storage elastic modulus after thermosetting can be reduced.

The film adhesive of the present invention preferably further contains a phosphorus catalyst. Since imidazole catalysts are incorporated into the cross-linked structure, they may cause an increase in storage modulus after thermosetting, but phosphorus catalysts are not incorporated into the cross-linked structure, so increase the storage elastic modulus after thermosetting. This is because it can be suppressed.

The present invention also includes a step of die-bonding the semiconductor chip on the adherend via the film-like adhesive, and a step of thermosetting the film-like adhesive after the step of die-bonding the semiconductor chip on the adherend. The present invention relates to a method for manufacturing a semiconductor device including:

The present invention also relates to a dicing tape and a dicing tape with a film adhesive provided with a thermosetting film adhesive disposed on the dicing tape.

The present invention also includes a step of disposing a semiconductor wafer on the film adhesive of the dicing tape with a film adhesive, a step of dicing the semiconductor wafer disposed on the film adhesive to form a semiconductor chip, After the step of picking up the semiconductor chip together with the film-like adhesive, the step of die-bonding the semiconductor chip on the adherend through the film-like adhesive, and the step of die-bonding the semiconductor chip on the adherend, the film-like The present invention relates to a method for manufacturing a semiconductor device including a step of thermally curing an adhesive.

The present invention also relates to a semiconductor device.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electroconductive film adhesive which can relieve the stress resulting from the difference of linear expansion, the dicing tape with a film adhesive, and a semiconductor device can be provided.

It is a schematic sectional drawing of a film adhesive. It is a schematic sectional drawing of a dicing tape with a film adhesive. It is a schematic sectional drawing of the dicing tape with a film adhesive which concerns on a modification. It is sectional drawing which shows the outline of a mode that the semiconductor wafer has been arrange | positioned on the dicing tape with a film adhesive. It is sectional drawing which shows the outline of a mode that the semiconductor wafer was separated into pieces. It is a schematic sectional drawing of a to-be-adhered body with a semiconductor chip. It is a schematic sectional drawing of a semiconductor device.

The present invention will be described in detail below with reference to embodiments, but the present invention is not limited only to these embodiments.

[Embodiment 1]
(Film adhesive)
As shown in FIG. 1, the form of the film adhesive 3 of Embodiment 1 is a film form. The film adhesive 3 has thermosetting properties.

About the resin component, the film adhesive 3 contains an epoxy resin, a phenol resin, and a high molecular weight acrylic resin. In the first embodiment, the phenol resin can function as a curing agent for the epoxy resin.

The storage elastic modulus at 150 ° C. after thermally curing the film adhesive 3 is 5 MPa or more, preferably 20 MPa or more. Since it is 5 MPa or more, wire bondability can be secured. On the other hand, the storage elastic modulus at 150 ° C. after thermosetting is 100 MPa or less. Since it is 100 MPa or less, it is possible to relieve the stress caused by the difference in linear expansion, and it is possible to reduce defects in the temperature cycle test.
The storage elastic modulus at 150 ° C. after thermosetting refers to the storage elastic modulus at 150 ° C. after thermosetting by heating at 140 ° C. for 1 hour and then at 200 ° C. for 1 hour. Specifically, it can be measured by the method described in the examples.

The storage elastic modulus at 150 ° C. after thermosetting can be controlled by the epoxy equivalent of epoxy resin, the hydroxyl equivalent of phenol resin, the acid value of high molecular weight acrylic resin, the acid value of low molecular weight acrylic resin, the particle size of conductive particles, etc. . For example, blending an epoxy resin having a large epoxy equivalent, blending a phenol resin having a large hydroxyl equivalent, blending a high molecular weight acrylic resin having a low acid value, blending a low molecular weight acrylic resin having a low acid value, By blending conductive particles having a large particle diameter, the storage elastic modulus at 150 ° C. after thermosetting can be lowered.

The epoxy resin is not particularly limited, and examples thereof include an epoxy resin having a bisphenol type skeleton, a cresol novolac type epoxy resin, a phenol novolac type epoxy resin, and a naphthalene type epoxy resin. Among these, an epoxy resin having a bisphenol type skeleton is preferable because the distance between the epoxy groups is long and the storage elastic modulus after thermosetting can be reduced. Examples of the epoxy resin having a bisphenol type skeleton include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

The epoxy equivalent of the epoxy resin is preferably 180 g / eq. Or more, more preferably 300 g / eq. Or more, more preferably 400 g / eq. That's it. On the other hand, the epoxy equivalent of the epoxy resin is preferably 3500 g / eq. Or less, more preferably 1500 g / eq. Hereinafter, more preferably 1000 g / eq. Hereinafter, 700 g / eq. It is as follows.
In addition, the epoxy equivalent of an epoxy resin can be measured by the method prescribed | regulated to JISK7236-2009.

The phenol resin acts as a curing agent for the epoxy resin. For example, a novolak type phenol resin such as a phenol novolak resin, a phenol aralkyl resin, a cresol novolak resin, a tert-butylphenol novolak resin, a nonylphenol novolak resin, or a resol type phenol resin. And polyoxystyrene such as polyparaoxystyrene.

The hydroxyl equivalent of the phenol resin is preferably 200 g / eq. That's it. 200 g / eq. When it is above, the storage elastic modulus after thermosetting can be easily reduced. On the other hand, the hydroxyl group equivalent of the phenol resin is preferably 3500 g / eq. Or less, more preferably 1500 g / eq. Hereinafter, more preferably 1000 g / eq. Or less, more preferably 700 g / eq. In the following, particularly preferably 300 g / eq. It is as follows.

The blending ratio of the epoxy resin and the phenol resin is preferably blended so that the hydroxyl group in the phenol resin is 0.5 to 2.0 equivalents per equivalent of epoxy group in the epoxy resin component. More preferred is 0.8 to 1.2 equivalents. That is, if the blending ratio of both is out of the above range, sufficient curing reaction does not proceed and the properties of the cured product are likely to deteriorate.

The total content of the epoxy resin and the phenol resin in the film adhesive 3 is preferably 5% by weight or more, more preferably 8% by weight or more, and further preferably 10% by weight or more. Hardness suitable about the film adhesive 3 after hardening as it is 5 weight% or more is obtained. The total content of the epoxy resin and the phenol resin is preferably 30% by weight or less, more preferably 20% by weight or less, and still more preferably 15% by weight or less. Suitable electroconductivity is acquired as it is 30 weight% or less.

The weight average molecular weight of the high molecular weight acrylic resin is preferably 200,000 or more, more preferably 300,000 or more, and further preferably 500,000 or more. The toughness suitable about the film adhesive 3 after hardening as it is 200,000 or more is obtained. On the other hand, the weight average molecular weight of the high molecular weight acrylic resin is preferably 1,000,000 or less, more preferably 950,000 or less. When it is 1,000,000 or less, the solubility in an organic solvent and the workability of the dissolved polymer solution are excellent.
The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

The high molecular weight acrylic resin is not particularly limited, and one or more esters of acrylic acid or methacrylic acid having a linear or branched alkyl group having 30 or less carbon atoms, particularly 4 to 18 carbon atoms. The polymer (acrylic copolymer) etc. which contain as a component is mentioned. Examples of the alkyl group include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2- Examples include ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, lauryl group, tridecyl group, tetradecyl group, stearyl group, octadecyl group, and dodecyl group.

In addition, the other monomer forming the polymer (acrylic copolymer) is not particularly limited, and for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid Or a carboxyl group-containing monomer such as crotonic acid, an acid anhydride monomer such as maleic anhydride or itaconic anhydride, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth ) 4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate or (4 -Hydroxymethylcyclo Hydroxyl group-containing monomers such as (xyl) -methyl acrylate, styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate Alternatively, a sulfonic acid group-containing monomer such as (meth) acryloyloxynaphthalene sulfonic acid or the like, or a phosphoric acid group-containing monomer such as 2-hydroxyethylacryloyl phosphate may be used.

The high molecular weight acrylic resin preferably contains a functional group capable of reacting with an epoxy group. Thereby, a high molecular weight acrylic resin can be bridge | crosslinked with an epoxy resin.

In the high molecular weight acrylic resin, examples of the functional group capable of reacting with the epoxy group include a carboxyl group and a hydroxyl group. Of these, a carboxyl group is preferred because of its high reactivity with an epoxy group.

The acid value of the high molecular weight acrylic resin is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, and further preferably 4 mgKOH / g or more. When it is 1 mgKOH / g or more, crosslinking between the high molecular weight acrylic resin and the epoxy resin is suitable, and a good cohesive force can be obtained for the film adhesive 3. On the other hand, the acid value of the high molecular weight acrylic resin is preferably 100 mgKOH / g or less, more preferably 50 mgKOH / g or less, and further preferably 30 mgKOH / g or less. When it is 100 mgKOH / g or less, it is possible to prevent the conductive particles from being corroded and to prevent a decrease in conductivity.
In addition, an acid value can be measured by the neutralization titration method prescribed | regulated to JISK0070-1992.

The acid equivalent of the high molecular weight acrylic resin is preferably 560 g / eq. Or more, more preferably 1120 g / eq. Or more, more preferably 1870 g / eq. That's it. 560 g / eq. When it is above, corrosion of the conductive particles can be prevented. On the other hand, the acid equivalent of the high molecular weight acrylic resin is preferably 56110 g / eq. Or less, More preferably, 18700 g / eq. Hereinafter, more preferably 14030 g / eq. It is as follows. 56110 g / eq. When it is below, good cohesive force can be obtained.
In addition, an acid equivalent can be calculated | required from an acid value.

The film adhesive 3 preferably contains a low molecular weight acrylic resin in addition to the high molecular weight acrylic resin. Thereby, a low molecular weight acrylic resin can be bridge | crosslinked with an epoxy resin.

In the low molecular weight acrylic resin, examples of the functional group capable of reacting with an epoxy group include a carboxyl group and a hydroxyl group. Of these, a carboxyl group is preferred because of its high reactivity with an epoxy group.

The acid value of the low molecular weight acrylic resin is preferably 10 mgKOH / g or more, more preferably 30 mgKOH / g or more, and further preferably 50 mgKOH / g or more. The storage elastic modulus after thermosetting can be easily adjusted to a suitable range as it is 10 mgKOH / g or more. On the other hand, the acid value of the low molecular weight acrylic resin is preferably 1000 mgKOH / g or less, more preferably 500 mgKOH / g or less, and still more preferably 300 mgKOH / g or less. When it is 1000 mgKOH / g or less, it is possible to prevent the conductive particles from being corroded and to prevent a decrease in conductivity.

The acid equivalent of the low molecular weight acrylic resin is preferably 56 g / eq. Or more, more preferably 187 g / eq. That's it. 56 g / eq. When it is as described above, it is possible to prevent the conductive particles from being corroded and to prevent a decrease in conductivity. On the other hand, the acid equivalent of the low molecular weight acrylic resin is preferably 5610 g / eq. Or less, more preferably 1120 g / eq. It is as follows. 5610 g / eq. The storage elastic modulus after thermosetting can be easily adjusted to a suitable range as it is below.

The weight average molecular weight of the low molecular weight acrylic resin is preferably 500 or more, more preferably 1000 or more, and further preferably 1500 or more. When it is 500 or more, the cohesiveness before curing of the film adhesive 3 can be enhanced. On the other hand, the weight average molecular weight of the low molecular weight acrylic resin is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 30,000 or less. When it is 100,000 or less, it is possible to suppress an increase in storage elastic modulus of the film adhesive 3 before curing, and good die attachability is obtained.

Examples of the low molecular weight acrylic resin include those containing a structural unit derived from a monomer containing a carboxyl group. Examples of the monomer containing a carboxyl group include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid and the like. Of these, acrylic acid is preferable because it is easily introduced into the polymer during polymer synthesis.

The low molecular weight acrylic resin may contain other structural units other than the structural unit derived from the monomer containing a carboxyl group. Examples of other structural units include structural units derived from styrene. By including the structural unit derived from styrene, the dispersibility with other compounding components becomes good.

The content of the acrylic resin in the film adhesive 3 is preferably 1% by weight or more, more preferably 2% by weight or more, and further preferably 4% by weight or more. When it is 1% by weight or more, good film formability can be obtained. On the other hand, the content of the acrylic resin is preferably 20% by weight or less, more preferably 10% by weight or less, and still more preferably 7% by weight or less. Suitable electroconductivity is acquired as it is 20 weight% or less.

When the film adhesive 3 contains a high molecular weight acrylic resin and a low molecular weight acrylic resin, the content of the high molecular weight acrylic resin in 100% by weight of the acrylic resin is preferably 70% by weight or more, more preferably 80% by weight or more, More preferably, it is 85 weight% or more. When it is 70% by weight or more, good film formability can be obtained. On the other hand, the content of the high molecular weight acrylic resin in 100% by weight of the acrylic resin is preferably 97% by weight or less, more preferably 95% by weight or less, and still more preferably 93% by weight or less. If it is 97% by weight or less, it can be adjusted to a suitable melt viscosity at the die attach temperature, and good die attachability can be obtained.

The film adhesive 3 preferably contains a curing catalyst. Thereby, thermosetting can be accelerated | stimulated. It does not specifically limit as a curing catalyst, For example, a phosphorus catalyst, an imidazole catalyst, etc. are mentioned. Of these, phosphorus-based catalysts are preferred. Since imidazole catalysts are incorporated into the cross-linked structure, they may cause an increase in storage modulus after thermosetting, but phosphorus catalysts are not incorporated into the cross-linked structure, so increase the storage elastic modulus after thermosetting. This is because it can be suppressed.

The phosphorus catalyst is not particularly limited, but tetraphenylphosphonium tetraphenylborate and tetraphenylphosphonium tetra-p-tolylborate are preferred for reasons of storage stability.

The content of the curing catalyst is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, and further preferably 1 part by weight or more with respect to 100 parts by weight of the epoxy resin. On the other hand, the content of the curing catalyst is preferably 10 parts by weight or less, more preferably 5 parts by weight or less with respect to 100 parts by weight of the epoxy resin. When it is 10 parts by weight or less, suitable storage stability can be obtained.

The film adhesive 3 includes conductive particles. Thereby, electroconductivity can be provided. Examples of the conductive particles include gold particles, silver particles, copper particles, and coated particles.

The coated particle includes a core particle and a coating film that coats the core particle. The core particles may be either conductive or non-conductive, and for example, glass particles can be used. Examples of the coating film include a film containing gold, a film containing silver, and a film containing copper.

The average particle diameter of the conductive particles is not particularly limited, but is preferably 0.001 times or more (thickness of the film adhesive 3 × 0.001 or more) with respect to the thickness of the film-like adhesive 3, and 0.1 times The above is more preferable. If it is less than 0.001, it is difficult to form a conductive path and the conductivity tends to be unstable. Further, the average particle diameter of the conductive particles is preferably 1 times or less (the thickness of the film adhesive 3 or less), more preferably 0.8 times or less with respect to the thickness of the film adhesive 3. If it exceeds 1 time, there is a risk of cracking the chip.
In addition, the average particle diameter of electroconductive particle is the value calculated | required with the photometric type particle size distribution meter (The product made from HORIBA, apparatus name; LA-910).

The specific gravity of the conductive particles is preferably 0.7 or more, and more preferably 1 or more. If it is less than 0.7, the conductive particles float when the adhesive composition solution (varnish) is produced, and the dispersion of the conductive particles may be uneven. The specific gravity of the conductive particles is preferably 22 or less, and more preferably 21 or less. If it exceeds 22, the conductive particles are likely to sink, and the dispersion of the conductive particles may be uneven.

The conductive particles include plate-like particles.

Examples of the plate-like particles include plate-like particles having an aspect ratio of 5 or more. When it is 5 or more, the plate-like particles are easily brought into surface contact with each other, and a conductive path is easily formed.
The aspect ratio is preferably 8 or more, more preferably 10 or more. On the other hand, the aspect ratio is preferably 10,000 or less, more preferably 100 or less, still more preferably 70 or less, and particularly preferably 50 or less.

The aspect ratio of the plate-like particles is the ratio of the average major axis to the average thickness (average major axis / average thickness).
In this specification, the average major axis of the plate-like particles is obtained by observing the cross section of the film-like adhesive 3 with a scanning electron microscope (SEM) and measuring the major axis of 100 randomly selected plate-like particles. Is the average value.
The average thickness of the plate-like particles is an average value obtained by observing the cross section of the film adhesive 3 with a scanning electron microscope (SEM) and measuring the thickness of 100 randomly selected plate-like particles. It is.

The average major axis of the plate-like particles is preferably 0.5 μm or more, more preferably 1.0 μm or more. When the thickness is 0.5 μm or more, the contact probability of the plate-like particles is increased, and conduction is easily obtained.
On the other hand, the average major axis of the plate-like particles is preferably 50 μm or less, more preferably 30 μm or less. When the thickness is 50 μm or less, particles are hardly precipitated at the coating varnish stage, and a stable coating varnish can be produced.

The content of the plate-like particles in 100% by weight of the conductive particles is 5% by weight or more, preferably 40% by weight or more, more preferably 60% by weight or more, and further preferably 70% by weight or more. The content of the plate-like particles in 100% by weight of the conductive particles may be 100% by weight, but is preferably 90% by weight or less, more preferably 85% by weight or less.

The conductive particles preferably include spherical spherical particles.

The content of spherical particles in 100% by weight of the conductive particles is preferably 10% by weight or more, more preferably 15% by weight or more. The content of spherical particles in 100% by weight of the conductive particles is preferably 95% by weight or less, more preferably 60% by weight or less, still more preferably 40% by weight or less, and particularly preferably 30% by weight or less.

The conductive particles may include acicular particles, filament particles, and the like.

The content of the conductive particles in the film adhesive 3 is preferably 30% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, still more preferably 75% by weight or more, particularly preferably. 80% by weight or more. If it is less than 30% by weight, it tends to be difficult to form a conductive path. The content of the conductive particles is preferably 95% by weight or less, more preferably 90% by weight or less, and still more preferably 88% by weight or less. If it exceeds 95% by weight, film formation tends to be difficult.

In addition to the above components, the film adhesive 3 may appropriately contain a compounding agent generally used for film production, for example, a crosslinking agent.

The film adhesive 3 can be manufactured by a normal method. For example, an adhesive composition solution containing each of the above components is prepared, and the adhesive composition solution is applied on a base separator so as to have a predetermined thickness to form a coating film, and then the coating film is dried. Thereby, the film adhesive 3 can be manufactured.

Although it does not specifically limit as a solvent used for adhesive composition solution, The organic solvent which can melt | dissolve, knead | mix or disperse | distribute each said component uniformly is preferable. Examples thereof include ketone solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, acetone, methyl ethyl ketone, and cyclohexanone, toluene, xylene, and the like. The application method is not particularly limited. Examples of the solvent coating method include a die coater, a gravure coater, a roll coater, a reverse coater, a comma coater, a pipe doctor coater, and screen printing. Of these, a die coater is preferable in terms of high uniformity of coating thickness.

As the base material separator, polyethylene terephthalate (PET), polyethylene, polypropylene, a plastic film or paper whose surface is coated with a release agent such as a fluorine-type release agent or a long-chain alkyl acrylate release agent can be used. Examples of the method for applying the adhesive composition solution include roll coating, screen coating, and gravure coating. Moreover, the drying conditions of a coating film are not specifically limited, For example, it can carry out in drying temperature 70-160 degreeC and drying time 1-5 minutes.

As a method for producing the film adhesive 3, for example, a method of producing the film adhesive 3 by mixing the respective components with a mixer and press-molding the obtained mixture is also suitable. A planetary mixer etc. are mentioned as a mixer.

Although the thickness of the film adhesive 3 is not specifically limited, 5 micrometers or more are preferable and 15 micrometers or more are more preferable. When the thickness is less than 5 μm, a portion where the warped semiconductor wafer or the semiconductor chip does not adhere may occur, and the adhesion area may become unstable. The thickness of the film adhesive 3 is preferably 100 μm or less, and more preferably 50 μm or less. If it exceeds 100 μm, the film adhesive 3 may protrude excessively due to the load of die attachment, and the pad may be contaminated.

The surface roughness (Ra) of the film adhesive 3 is preferably 0.1 to 5000 nm. If it is less than 0.1 nm, it is difficult to blend. On the other hand, if it exceeds 5000 nm, the adherence to the adherend during die attachment may be reduced.

The electrical resistivity of the film adhesive 3 is preferably as low as possible, for example, 9 × 10 ⁻² Ω · m or less. When it is 9 × 10 ⁻² Ω · m or less, the electroconductivity is good and it is possible to cope with small size and high density mounting. On the other hand, the electrical resistivity is preferably 1 × 10 ⁻⁶ Ω · m or more.

The higher the thermal conductivity of the film adhesive 3 is, the more preferable, for example, 0.5 W / m · K or more. When it is 0.5 W / m · K or more, the heat dissipation is good, and it is possible to cope with small and high-density mounting. On the other hand, if it is less than 0.5 W / m · K, heat dissipation is poor, heat is accumulated, and the conductivity may be deteriorated.

The tensile storage elastic modulus at 120 ° C. of the film adhesive 3 is preferably 10 MPa or less, more preferably 5 MPa or less. When it is 10 MPa or less, the fluidity of the film adhesive 3 in the vicinity of the thermosetting temperature is high, and it is easy to eliminate voids by heating under pressure. The tensile storage modulus at 120 ° C. is preferably 0.01 MPa or more, more preferably 0.05 MPa or more. When it is 0.01 MPa or more, the film adhesive 3 is difficult to protrude.
The tensile storage elastic modulus at 120 ° C. can be measured by the following method.

Measurement of tensile storage modulus at 120 ° C. A strip-shaped measurement piece having a length of 30 mm, a width of 10 mm, and a thickness of 400 μm is cut out from the film-like adhesive 3. About the measurement piece, using a fixed viscoelasticity measuring device (RSA-II, manufactured by Rheometric Scientific), the chuck storage width is 22.6 mm, the tensile storage elastic modulus at 0 ° C. to 200 ° C. is a frequency of 1 Hz, and the heating rate is 10 Measure under conditions of ° C / min.

The tensile storage modulus at 120 ° C. can be controlled by the glass transition temperature of the thermoplastic resin, the blending amount of conductive particles, and the like. For example, by blending a thermoplastic resin having a low glass transition temperature, the tensile storage elastic modulus at 120 ° C. can be lowered.

The film adhesive 3 is used for manufacturing a semiconductor device. Especially, it can be used especially suitably for manufacture of a power semiconductor device. Specifically, it is used as a die attach film that adheres (die attaches) an adherend such as a lead frame and a semiconductor chip. Examples of the adherend include a lead frame, an interposer, and a semiconductor chip. Of these, a lead frame is preferable.

The film adhesive 3 is preferably used in the form of a dicing tape with a film adhesive. When used in this form, the semiconductor wafer in a state of being attached to the dicing tape with a film adhesive can be handled, so that the opportunity to handle the semiconductor wafer alone can be reduced and the handling property is good. Therefore, even a recent thin semiconductor wafer can be handled well.

[Dicing tape with film adhesive]
The dicing tape with a film adhesive will be described.

As shown in FIG. 2, the dicing tape 10 with a film adhesive includes a dicing tape 1 and a film adhesive 3 disposed on the dicing tape 1. The dicing tape 1 includes a base material 11 and an adhesive layer 12 arranged on the base material 11. The film adhesive 3 is disposed on the pressure-sensitive adhesive layer 12.

As shown in FIG. 3, the dicing tape 10 with a film adhesive may have a configuration in which the film adhesive 3 is formed only on a work (semiconductor wafer 4 or the like) affixed portion.

The base material 11 serves as a strength matrix of the dicing tape 10 with a film adhesive, and preferably has ultraviolet transparency. Examples of the base material 11 include low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolyprolene, polybutene, and polymethylpentene. Polyolefin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, ethylene -Hexene copolymers, polyesters such as polyurethane, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyetheretherketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamid , Polyphenyl sulphates id, aramid (paper), glass, glass cloth, fluorine resin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, silicone resin, metal (foil), and paper.

The surface of the base material 11 is chemically treated by conventional surface treatments such as chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation treatment, etc. in order to improve adhesion and retention with adjacent layers. Alternatively, a physical treatment or a coating treatment with a primer (for example, an adhesive substance described later) can be performed.

The thickness of the substrate 11 is not particularly limited and can be determined as appropriate, but is generally about 5 to 200 μm.

It does not restrict | limit especially as an adhesive used for formation of the adhesive layer 12, For example, common pressure sensitive adhesives, such as an acrylic adhesive and a rubber adhesive, can be used. As pressure-sensitive adhesives, acrylic adhesives based on acrylic polymers are used as the base polymer from the standpoint of cleanability of electronic components that are difficult to contaminate such as semiconductor wafers and glass with organic solvents such as ultrapure water and alcohol. preferable.

Examples of the acrylic polymer include (meth) acrylic acid alkyl esters (for example, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopropyl ester). Pentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, tridecyl ester, tetradecyl ester, hexadecyl ester, C1-C30, especially C4-C18 linear or branched alkyl esters of alkyl groups such as octadecyl ester and eicosyl ester) and Meth) acrylic acid cycloalkyl esters (e.g., cyclopentyl ester, etc. One or acrylic polymer using two or more of the monomer component cyclohexyl ester etc.). In addition, (meth) acrylic acid ester means acrylic acid ester and / or methacrylic acid ester, and (meth) of the present invention has the same meaning.

The acrylic polymer contains units corresponding to other monomer components copolymerizable with the (meth) acrylic acid alkyl ester or cycloalkyl ester, if necessary, for the purpose of modifying cohesive force, heat resistance and the like. May be. Examples of such monomer components include, for example, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; maleic anhydride Acid anhydride monomers such as itaconic anhydride; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate Hydroxyl group-containing monomers such as 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate; Sti Contains sulfonic acid groups such as sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid Monomers; Phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate; acrylamide, acrylonitrile and the like. One or more of these copolymerizable monomer components can be used. The amount of these copolymerizable monomers used is preferably 40% by weight or less based on the total monomer components.

Furthermore, since the acrylic polymer is cross-linked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization as necessary. Examples of such polyfunctional monomers include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) An acrylate etc. are mentioned. These polyfunctional monomers can also be used alone or in combination of two or more. The amount of the polyfunctional monomer used is preferably 30% by weight or less of the total monomer components from the viewpoint of adhesive properties and the like.

The acrylic polymer can be obtained by subjecting a single monomer or a mixture of two or more monomers to polymerization. The polymerization can be carried out by any method such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization and the like. From the viewpoint of preventing contamination of a clean adherend, it is preferable that the content of the low molecular weight substance is small. From this point, the number average molecular weight of the acrylic polymer is preferably 300,000 or more, more preferably about 400,000 to 3,000,000.

In addition, an external cross-linking agent can be appropriately employed for the pressure-sensitive adhesive in order to increase the number average molecular weight of an acrylic polymer as a base polymer. Specific examples of the external crosslinking method include a method of adding a so-called crosslinking agent such as a polyisocyanate compound, an epoxy compound, an aziridine compound, or a melamine crosslinking agent and reacting them. When using an external cross-linking agent, the amount used is appropriately determined depending on the balance with the base polymer to be cross-linked and further depending on the intended use as an adhesive. Generally, it is preferable to add about 5 parts by weight or less, and further 0.1 to 5 parts by weight with respect to 100 parts by weight of the base polymer. Furthermore, additives such as various conventionally known tackifiers and anti-aging agents may be used for the pressure-sensitive adhesive, if necessary, in addition to the above components.

The pressure-sensitive adhesive layer 12 can be formed of a radiation curable pressure-sensitive adhesive. The radiation curable pressure-sensitive adhesive can easily reduce its adhesive strength by increasing the degree of crosslinking by irradiation with radiation such as ultraviolet rays.

By irradiating only the part 12a corresponding to the work pasting part of the pressure-sensitive adhesive layer 12 shown in FIG. 2, a difference in adhesive strength with the other part 12b can be provided. In this case, the portion 12b formed of the uncured radiation curable pressure-sensitive adhesive sticks to the film adhesive 3 and can secure a holding force when dicing.

Moreover, the said part 12a in which adhesive force fell remarkably can be formed by hardening the radiation-curing-type adhesive layer 12 according to the film adhesive 3 shown in FIG. In this case, the wafer ring can be fixed to the portion 12b formed of an uncured radiation curable adhesive.

That is, when the pressure-sensitive adhesive layer 12 is formed of a radiation curable pressure-sensitive adhesive, the portion 12a is irradiated with radiation so that the pressure-sensitive adhesive force of the portion 12a in the pressure-sensitive adhesive layer 12 <the pressure-sensitive adhesive strength of the other portion 12b. It is preferable.

As the radiation curable pressure-sensitive adhesive, those having a radiation curable functional group such as a carbon-carbon double bond and exhibiting adhesiveness can be used without particular limitation. Examples of the radiation curable pressure-sensitive adhesive include an addition-type radiation curable pressure-sensitive adhesive in which a radiation-curable monomer component or oligomer component is blended with a general pressure-sensitive pressure-sensitive adhesive such as the acrylic pressure-sensitive adhesive or rubber-based pressure-sensitive adhesive. An agent can be illustrated.

Examples of the radiation curable monomer component to be blended include urethane oligomer, urethane (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol. Examples include stall tetra (meth) acrylate, dipentaerystol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, and the like. Examples of the radiation curable oligomer component include various oligomers such as urethane, polyether, polyester, polycarbonate, and polybutadiene, and those having a molecular weight in the range of about 100 to 30000 are suitable. The compounding amount of the radiation-curable monomer component or oligomer component can be appropriately determined in accordance with the type of the pressure-sensitive adhesive layer, and the amount capable of reducing the adhesive strength of the pressure-sensitive adhesive layer. Generally, the amount is, for example, about 5 to 500 parts by weight, preferably about 40 to 150 parts by weight with respect to 100 parts by weight of a base polymer such as an acrylic polymer constituting the pressure-sensitive adhesive.

In addition to the additive-type radiation curable adhesive described above, the radiation curable pressure-sensitive adhesive has a carbon-carbon double bond in the polymer side chain or main chain or at the main chain terminal as a base polymer. Intrinsic radiation curable pressure sensitive adhesives using Intrinsic radiation curable adhesives do not need to contain oligomer components, which are low molecular components, or do not contain many, so the oligomer components do not move through the adhesive over time and are stable. It is preferable because an adhesive layer having a layered structure can be formed.

As the base polymer having a carbon-carbon double bond, those having a carbon-carbon double bond and having adhesiveness can be used without particular limitation. As such a base polymer, those having an acrylic polymer as a basic skeleton are preferable. Examples of the basic skeleton of the acrylic polymer include the acrylic polymers exemplified above.

The method for introducing the carbon-carbon double bond into the acrylic polymer is not particularly limited, and various methods can be adopted. However, the carbon-carbon double bond can be easily introduced into the polymer side chain for easy molecular design. . For example, after a monomer having a functional group is previously copolymerized with an acrylic polymer, a compound having a functional group capable of reacting with the functional group and a carbon-carbon double bond is converted into a radiation curable carbon-carbon double bond. A method of performing condensation or addition reaction while maintaining the above.

Examples of combinations of these functional groups include carboxylic acid groups and epoxy groups, carboxylic acid groups and aziridyl groups, hydroxyl groups and isocyanate groups. Among these combinations of functional groups, a combination of a hydroxyl group and an isocyanate group is preferable because of easy tracking of the reaction. Moreover, the functional group may be on either side of the acrylic polymer and the compound as long as the acrylic polymer having the carbon-carbon double bond is generated by a combination of these functional groups. In the preferable combination, it is preferable that the acrylic polymer has a hydroxyl group and the compound has an isocyanate group. In this case, examples of the isocyanate compound having a carbon-carbon double bond include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, and the like. Further, as the acrylic polymer, those obtained by copolymerizing the above-exemplified hydroxy group-containing monomers, ether compounds of 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, or the like are used.

As the intrinsic radiation curable pressure-sensitive adhesive, the base polymer (particularly acrylic polymer) having the carbon-carbon double bond can be used alone, but the radiation curable monomer does not deteriorate the characteristics. Components and oligomer components can also be blended. The radiation-curable oligomer component or the like is usually in the range of 30 parts by weight, preferably in the range of 0 to 10 parts by weight with respect to 100 parts by weight of the base polymer.

The radiation curable pressure-sensitive adhesive contains a photopolymerization initiator when cured by ultraviolet rays or the like. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, 2-methyl-2-hydroxypropio Α-ketol compounds such as phenone and 1-hydroxycyclohexyl phenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- ( Acetophenone compounds such as methylthio) -phenyl] -2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether and anisoin methyl ether; ketal compounds such as benzyldimethyl ketal; 2-naphthalenesulfo Aromatic sulfonyl chloride compounds such as luchloride; Photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; benzophenone, benzoylbenzoic acid, 3,3′-dimethyl Benzophenone compounds such as -4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2 Thioxanthone compounds such as 1,4-diethylthioxanthone and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketone; acyl phosphinoxide; acyl phosphonate. The compounding quantity of a photoinitiator is about 0.05-20 weight part with respect to 100 weight part of base polymers, such as an acryl-type polymer which comprises an adhesive.

Examples of the radiation curable pressure-sensitive adhesive include photopolymerizable compounds such as an addition polymerizable compound having two or more unsaturated bonds and an alkoxysilane having an epoxy group disclosed in JP-A-60-196956. And rubber-based pressure-sensitive adhesives and acrylic pressure-sensitive adhesives containing photopolymerization initiators such as carbonyl compounds, organic sulfur compounds, peroxides, amines, and onium salt-based compounds.

The radiation curable pressure-sensitive adhesive layer 12 may contain a compound that is colored by radiation irradiation, if necessary. By including a compound to be colored in the pressure-sensitive adhesive layer 12 by irradiation with radiation, only the irradiated portion can be colored. The compound that is colored by irradiation with radiation is a colorless or light color compound before irradiation with radiation, but becomes a color by irradiation with radiation, and examples thereof include leuco dyes. The use ratio of the compound colored by radiation irradiation can be set as appropriate.

The thickness of the pressure-sensitive adhesive layer 12 is not particularly limited, but is preferably about 1 to 50 μm from the viewpoint of preventing chipping of the chip cut surface and compatibility of fixing and holding the film adhesive 3. Preferably it is 2-30 micrometers, Furthermore, 5-25 micrometers is preferable.

The film adhesive 3 of the dicing tape 10 with a film adhesive is preferably protected by a separator (not shown). The separator has a function as a protective material for protecting the film adhesive 3 until it is put into practical use. The separator is peeled off when the workpiece is stuck on the film adhesive 3. As the separator, it is also possible to use polyethylene terephthalate (PET), polyethylene, polypropylene, a plastic film or paper whose surface is coated with a release agent such as a fluorine release agent or a long-chain alkyl acrylate release agent.

The dicing tape 10 with a film adhesive can be manufactured by a normal method. For example, the dicing tape 10 with a film adhesive can be manufactured by bonding the adhesive layer 12 of the dicing tape 1 and the film adhesive 3 together.

It is preferable that the peeling force when the film-like adhesive 3 is peeled off from the dicing tape 1 is 0.01 to 3.00 N / 20 mm under the conditions of a peeling temperature of 25 ° C. and a peeling speed of 300 mm / min. If it is less than 0.01 N / 20 mm, there is a risk of chip jumping during dicing. On the other hand, if it exceeds 3.00 N / 20 mm, the pickup tends to be difficult.

[Method for Manufacturing Semiconductor Device]
A method for manufacturing a semiconductor device will be described.

As shown in FIG. 4, a dicing tape 10 with a film adhesive is pressure-bonded to the semiconductor wafer 4. Examples of the semiconductor wafer 4 include a silicon wafer, a silicon carbide wafer, and a compound semiconductor wafer. Examples of compound semiconductor wafers include gallium nitride wafers.

Examples of the crimping method include a method of pressing with a pressing means such as a crimping roll.

The pressing temperature (sticking temperature) is preferably 35 ° C. or higher, and more preferably 50 ° C. or higher. The upper limit of the pressure bonding temperature is preferably lower, preferably 80 ° C. or lower, more preferably 50 ° C. or lower, and further preferably 45 ° C. or lower. By crimping at a low temperature, it is possible to prevent the thermal effect on the semiconductor wafer 4 and to suppress warping of the semiconductor wafer 4.

Moreover, it is preferable that it is 1 * 10 < ⁵ > Pa-1 * 10 < ⁷ > Pa, and it is more preferable that a pressure is 2 * 10 < ⁵ > Pa-8 * 10 < ⁶ > Pa.

Next, as shown in FIG. 5, the semiconductor wafer 4 is diced. That is, the semiconductor wafer 4 is cut into a predetermined size and separated into pieces, and the semiconductor chip 5 is cut out. Dicing is performed according to a conventional method. Further, in this step, for example, a cutting method called full cut in which cutting is performed up to the dicing tape 10 with a film adhesive can be employed. It does not specifically limit as a dicing apparatus used at this process, A conventionally well-known thing can be used. Moreover, since the semiconductor wafer 4 is bonded and fixed by the dicing tape 10 with a film adhesive, chip chipping and chip jump can be suppressed, and damage to the semiconductor wafer 4 can also be suppressed.

The semiconductor chip 5 is picked up in order to peel off the semiconductor chip 5 bonded and fixed to the dicing tape with film adhesive 10. The pickup method is not particularly limited, and various conventionally known methods can be employed. For example, there is a method in which each semiconductor chip 5 is pushed up by a needle from the dicing tape 10 with film adhesive, and the pushed-up semiconductor chip 5 is picked up by a pickup device.

Here, when the pressure-sensitive adhesive layer 12 is an ultraviolet curable type, the pickup is performed after the pressure-sensitive adhesive layer 12 is irradiated with ultraviolet rays. Thereby, the adhesive force with respect to the film adhesive 3 of the adhesive layer 12 falls, and peeling of the semiconductor chip 5 becomes easy. As a result, the pickup can be performed without damaging the semiconductor chip 5. Conditions such as irradiation intensity and irradiation time at the time of ultraviolet irradiation are not particularly limited, and may be set as necessary.

As shown in FIG. 6, the picked-up semiconductor chip 5 is bonded and fixed to the adherend 6 via the film adhesive 3 to obtain an adherend 61 with a semiconductor chip. The adherend 61 with a semiconductor chip includes an adherend 6, a film adhesive 3 disposed on the adherend 6, and a semiconductor chip 5 disposed on the film adhesive 3.

The die attach temperature is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 130 ° C. or higher. The die attach temperature is preferably 170 ° C. or lower, more preferably 160 ° C. or lower. By setting the temperature to 170 ° C. or lower, it is possible to prevent warping after die attachment.

Subsequently, by heating the adherend 61 with a semiconductor chip, the film adhesive 3 is thermally cured, and the semiconductor chip 5 and the adherend 6 are fixed. It is preferable to thermally cure the film adhesive 3 by heating the adherend 61 with a semiconductor chip under pressure. By thermally curing the film adhesive 3 under pressure, voids existing between the film adhesive 3 and the adherend 6 can be eliminated, and the film adhesive 3 is adhered to the adherend 6. The area in contact with can be secured.

Examples of a method of heating under pressure include a method of heating the adherend 61 with a semiconductor chip disposed in a chamber filled with an inert gas.
The pressure of the pressurized atmosphere is preferably 0.5 kg / cm ² (4.9 × 10 ⁻² MPa) or more, more preferably 1 kg / cm ² (9.8 × 10 ⁻² MPa) or more, and further preferably 5 kg. / Cm ² (4.9 × 10 ⁻¹ MPa) or more. If it is 0.5 kg / cm ² or more, voids existing between the film adhesive 3 and the adherend 6 can be easily eliminated. The pressure of the pressurized atmosphere is preferably 20kg ^/ cm 2 (1.96MPa), more preferably 18kg ^/ cm 2 (1.77MPa) or less, more preferably not more than 15kg ^/ cm 2 (1.47MPa). The protrusion of the film adhesive 3 due to excessive pressurization can be suppressed as it is 20 kg / cm ² or less.

The heating temperature when heating under pressure is preferably 80 ° C or higher, more preferably 100 ° C or higher, still more preferably 120 ° C or higher, and particularly preferably 170 ° C or higher. When the temperature is 80 ° C. or higher, the film-like adhesive 3 can have an appropriate hardness, and voids can be effectively eliminated by pressure curing.
The heating temperature is preferably 260 ° C. or lower, more preferably 200 ° C. or lower, more preferably 180 ° C. or lower. It can prevent decomposition | disassembly of the film adhesive 3 before hardening as it is 260 degrees C or less.

The heating time is preferably 0.1 hour or longer, more preferably 0.2 hour or longer, and further preferably 0.5 hour or longer. When it is 0.1 hour or longer, the effect of pressurization can be sufficiently obtained. The heating time is preferably 24 hours or less, more preferably 3 hours or less, and even more preferably 1 hour or less.

Next, a wire bonding step of electrically connecting the tip of the terminal portion (inner lead) of the adherend 6 and an electrode pad (not shown) on the semiconductor chip 5 with the bonding wire 7 is performed. As the bonding wire 7, for example, a gold wire, an aluminum wire or a copper wire is used. The temperature during wire bonding is preferably 80 ° C. or higher, more preferably 120 ° C. or higher, and the temperature is preferably 250 ° C. or lower, more preferably 175 ° C. or lower. The heating time is several seconds to several minutes (for example, 1 second to 1 minute). The connection is performed by a combination of vibration energy by ultrasonic waves and pressure energy by pressurization while being heated so as to be within the temperature range.

Subsequently, a sealing step for sealing the semiconductor chip 5 with the sealing resin 8 is performed. This step is performed to protect the semiconductor chip 5 and the bonding wire 7 mounted on the adherend 6. This step is performed by molding a sealing resin with a mold. As the sealing resin 8, for example, an epoxy resin is used. The heating temperature at the time of resin sealing is preferably 165 ° C. or higher, more preferably 170 ° C. or higher, and the heating temperature is preferably 185 ° C. or lower, more preferably 180 ° C. or lower.

If necessary, the sealed material may be further heated (post-curing step). Thereby, the sealing resin 8 which is insufficiently cured in the sealing process can be completely cured. The heating temperature can be set as appropriate.

As described above, in the first embodiment, the film is formed after the step of die-bonding the semiconductor chip 5 on the adherend 6 and the step of die-bonding the semiconductor chip 5 on the adherend 6 via the film adhesive 3. A semiconductor device is manufactured by a method including a step of thermally curing the adhesive 3.

More specifically, the method of Embodiment 1 includes the steps of placing the semiconductor wafer 4 on the film adhesive 3 of the dicing tape 10 with film adhesive, and the semiconductor wafer disposed on the film adhesive 3. The semiconductor chip 5 is die-bonded onto the adherend 6 via the step of dicing 4 to form the semiconductor chip 5, the step of picking up the semiconductor chip 5 together with the film adhesive 3, and the film adhesive 3. After the step and the step of die-bonding the semiconductor chip 5 on the adherend 6, the step of thermally curing the film adhesive 3 is included.

The first embodiment has been described above.

[Embodiment 2]
(Film adhesive)
The second embodiment is different from the first embodiment in the composition of the film adhesive 3.

Regarding the resin component, the film adhesive 3 of Embodiment 2 includes an epoxy resin, a high molecular weight acrylic resin, and a low molecular weight acrylic resin containing a functional group capable of reacting with an epoxy group. In Embodiment 2, the low molecular weight acrylic resin can function as a curing agent for the epoxy resin. Therefore, in Embodiment 2, it is not necessary to add a phenol resin.

A suitable epoxy resin is the same as in the first embodiment.

The content of the epoxy resin in the film adhesive 3 is preferably 1% by weight or more, more preferably 2% by weight or more, and further preferably 3% by weight or more. A suitable hardened | cured material can be obtained as it is 1 weight% or more. The content of the epoxy resin is preferably 15% by weight or less, more preferably 10% by weight or less, and still more preferably 7% by weight or less. Suitable electroconductivity is acquired as it is 15 weight% or less.

A suitable high molecular weight acrylic resin is the same as in the first embodiment.

The low molecular weight acrylic resin contains a functional group capable of reacting with an epoxy group. Examples of the functional group capable of reacting with the epoxy group include a carboxyl group and a hydroxyl group. Of these, a carboxyl group is preferred because of its high reactivity with an epoxy group.

The suitable acid value, acid equivalent, weight average molecular weight, etc. of the low molecular weight acrylic resin are the same as those in the first embodiment.

The content of the acrylic resin in the film adhesive 3 is preferably 1% by weight or more, more preferably 5% by weight or more, still more preferably 10% by weight or more, and particularly preferably 12% by weight or more. When it is 1% by weight or more, good film formability can be obtained. On the other hand, the content of the acrylic resin is preferably 20% by weight or less, more preferably 17% by weight or less, and still more preferably 15% by weight or less. Suitable electroconductivity is acquired as it is 20 weight% or less.

The content of the high molecular weight acrylic resin in 100% by weight of the acrylic resin is preferably 20% by weight or more, more preferably 30% by weight or more, and further preferably 40% by weight or more. When it is 20% by weight or more, it is possible to prevent the film adhesive 3 from being excessively melted at the temperature at the time of die attachment, and the protrusion of the film adhesive 3 can be suppressed. On the other hand, the content of the high molecular weight acrylic resin in 100% by weight of the acrylic resin is preferably 98% by weight or less, more preferably 80% by weight or less, and still more preferably 60% by weight or less. Suitable electroconductivity is acquired as it is 98 weight% or less.

The film adhesive 3 preferably contains a curing catalyst. A suitable curing catalyst is the same as in the first embodiment. The preferred content of the curing catalyst is the same as in the first embodiment.

The film adhesive 3 preferably contains conductive particles. Suitable conductive particles are the same as those in the first embodiment. The preferred content of the conductive particles is the same as in the first embodiment.

The second embodiment has been described above.

EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

The components used in the examples will be described.
Teisan Resin SG-70L: Teisan Resin SG-70L manufactured by Nagase ChemteX Corporation (acrylic copolymer containing carboxyl group and hydroxyl group, Mw: 900,000, acid value: 5 mg KOH / g, acid equivalent: 11222 g / eq .)
Pararaclon W-248E: Paraclone W-248E manufactured by Negami Kogyo Co., Ltd. (acrylic resin containing hydroxyl group, Mw: 450,000, acid value: 8.5 mgKOH / g, acid equivalent: 6601 g / eq.)
Alfon UC-3510: Alfon UC-3510 manufactured by Toa Gosei Co., Ltd. (acrylic resin containing carboxyl group, Mw: 2000, acid value: 70 mg KOH / g, acid equivalent: 802 g / eq.)
Alfon UC-3080: Alfon UC-3080 manufactured by Toa Gosei Co., Ltd. (acrylic resin containing carboxyl group, Mw: 14000, acid value: 230 mgKOH / g, acid equivalent: 244 g / eq.)
JER828: JER828 manufactured by Mitsubishi Chemical Corporation (epoxy resin having a bisphenol type skeleton, Epokin equivalent 184 g / eq. To 194 g / eq.)
EXA-4850-150: EPICLON EXA-4850-150 (epoxy resin having a bisphenol type skeleton, epoxy equivalent 450 g / eq.) Manufactured by DIC Corporation
JER1001: JER1001 manufactured by Mitsubishi Chemical Corporation (epoxy resin having a bisphenol-type skeleton, epoxy equivalent of 450 g / eq. To 500 g / eq.)
JER1004: JER1004 manufactured by Mitsubishi Chemical Corporation (epoxy resin having a bisphenol-type skeleton, epoxy equivalent of 875 g / eq. To 975 g / eq.)
HP-4032D: EPICLON HP-4032D manufactured by DIC Corporation (epoxy resin having a naphthalene-type skeleton, epoxy equivalent: 136 g / eq. To 148 g / eq.)
EPPN-501HY: Nippon Kayaku Co., Ltd. EPPN-501HY (an epoxy resin having a polyfunctional skeleton, epoxy equivalent of 163 g / eq. To 175 g / eq.)
MEH-7851SS: MEH-7851SS (phenol resin, hydroxyl group equivalent 201 g / eq. To 205 g / eq.) Manufactured by Meiwa Kasei Co., Ltd.
MEH-7851-4H: MEH-7851-4H (phenol resin, hydroxyl group equivalent: 235 g / eq. To 245 g / eq.) Manufactured by Meiwa Kasei Co., Ltd.
MEH-8000H: MEH-8000H manufactured by Meiwa Kasei Co., Ltd. (phenol resin, hydroxyl group equivalent of 139 g / eq. To 143 g / eq.)
TPP-K: TPP-K (tetraphenylphosphonium tetraphenylborate) manufactured by Hokuko Chemical Co., Ltd.
1200YP: 1200YP manufactured by Mitsui Mining & Smelting Co., Ltd. (flaked copper powder, average particle size 3.5 μm, aspect ratio: 10, specific gravity 8.9)
EHD: EHD manufactured by Mitsui Mining & Smelting Co., Ltd. (silver powder, spherical, average particle size 0.7 μm, specific gravity 10.5)

[Production of film adhesive and dicing tape with film adhesive]
(Examples 1-7 and Comparative Example 1)
According to the mixing ratio shown in Table 1, each component and solvent (methyl ethyl ketone) shown in Table 1 were placed in a stirring vessel of a hybrid mixer (HM-500 manufactured by Keyence), and stirred and mixed in a stirring mode for 3 minutes. The obtained varnish was applied to a release treatment film (MRA50 manufactured by Mitsubishi Resin Co., Ltd.) with a die coater and then dried to produce a film adhesive having a thickness of 30 μm.

The obtained film adhesive was cut into a circle having a diameter of 230 mm and pasted on a pressure-sensitive adhesive layer of a dicing tape (P2130G manufactured by Nitto Denko Corporation) at 25 ° C. to prepare a dicing tape with a film adhesive. .

[Production of mirror silicon wafer]
Using a back grinder (DFG-8560 manufactured by DISCO Corporation), the silicon wafer (manufactured by Shin-Etsu Chemical Co., Ltd., thickness 0.6 mm) is ground so that the thickness becomes 0.1 mm. Produced.

[Evaluation]
The following evaluation was performed about the obtained film adhesive and the dicing tape with a film adhesive. The results are shown in Table 1.

(Storage modulus at 150 ° C after thermosetting)
The film adhesive was laminated until the thickness became 500 μm. Then, it heated at 140 degreeC for 1 hour, and also heat-cured by heating at 200 degreeC for 1 hour. Next, it is cut into a strip shape having a length of 22.5 mm (measurement length) and a width of 10 mm with a cutter knife, and using a solid viscoelasticity measuring device (RSAII, manufactured by Rheometric Scientific Co., Ltd.), -50 ° C The storage modulus at ˜300 ° C. was measured. The measurement conditions were a frequency of 1 Hz and a heating rate of 10 ° C./min. The value at 150 ° C. at that time was taken as the measured value of the storage elastic modulus at 150 ° C. after thermosetting.

(Temperature cycle evaluation)
A mirror silicon wafer was bonded to the film adhesive surface of the dicing tape with film adhesive. The bonding was performed using a wafer mounter (manufactured by Nitto Seiki) MA-3000III at a bonding speed of 10 mm / min and a bonding temperature of 70 ° C. Next, dicing was performed with a dicing machine to obtain a 5 mm × 5 mm chip with film adhesive. Thereafter, the chip with film adhesive was die-attached to a copper lead frame (Dai Nippon Printing Co., Ltd., product name: QFN32, 64) with a die bonder. The die attach conditions were as follows: temperature: 150 ° C., holding time: 0.5 seconds, pressure: 0.5 MPa. Then, after hold | maintaining at 140 degreeC for 1 hour, it heated at 200 degreeC for 1 hour, the film adhesive was thermosetted, and the package for temperature cycle evaluation was obtained. Ten packages were subjected to a heat cycle test of 1000 cycles at a temperature of −55 ° C. to 150 ° C. The test was conducted in accordance with JEDEC Standard 22-A104C Condition H.
After the thermal cycle test, 10 packages were observed with an ultrasonic microscope. When even one chip peeling was confirmed, it was judged as x, and when no peeling was confirmed in all 10 packages, Judged.

[Comprehensive judgment]
The case where all the following conditions were satisfied was determined as “good”, and the case where any one of the following conditions was not satisfied was determined as “poor”.
Condition (1): The storage elastic modulus at 150 ° C. after thermosetting is 5 MPa to 100 MPa.
Condition (2): The determination result of the temperature cycle evaluation is ◯.

DESCRIPTION OF SYMBOLS 10 Dicing tape 1 with a film adhesive Dicing tape 11 Base material 12 Adhesive layer 3 Film adhesive 4 Semiconductor wafer 5 Semiconductor chip 6 Adhering body 61 Adhering body with a semiconductor chip 7 Bonding wire 8 Sealing resin

Claims (12)

Including acrylic resin, epoxy resin and conductive particles,
The conductive particles include plate-like particles having an aspect ratio of 5 or more,
The content of the plate-like particles in 100% by weight of the conductive particles is 5% by weight to 100% by weight,
A thermosetting film adhesive having a storage elastic modulus at 150 ° C. of 5 to 100 MPa after thermosetting. The film adhesive according to claim 1, wherein the epoxy resin has a bisphenol type skeleton. The epoxy equivalent of the epoxy resin is 180 g / eq. ~ 3500 g / eq. The film adhesive according to claim 1 or 2. Further comprising a phenolic resin,
The phenol resin has a hydroxyl group equivalent of 200 g / eq. It is the above, The film adhesive in any one of Claims 1-3. The film adhesive according to any one of claims 1 to 4, wherein the acrylic resin contains a high molecular weight acrylic resin having a weight average molecular weight of 200,000 to 1,000,000. The acrylic resin includes a low molecular weight acrylic resin having a weight average molecular weight of 500 to 100,000,
The film adhesive in any one of Claims 1-5 in which the said low molecular weight acrylic resin contains the functional group which reacts with an epoxy group. The film adhesive according to any one of claims 1 to 6, further comprising a phosphorus catalyst. A step of die-bonding a semiconductor chip on an adherend through the film adhesive according to any one of claims 1 to 7,
And a step of thermosetting the film adhesive after the step of die-bonding the semiconductor chip onto an adherend. A semiconductor device obtained by the manufacturing method according to claim 8. A dicing tape, and a thermosetting film adhesive disposed on the dicing tape,
The film adhesive includes an acrylic resin, an epoxy resin and conductive particles,
The conductive particles include plate-like particles having an aspect ratio of 5 or more,
The content of the plate-like particles in 100% by weight of the conductive particles is 5% by weight to 100% by weight,
The said film adhesive is a dicing tape with a film adhesive whose storage elastic modulus in 150 degreeC after thermosetting is 5 MPa-100 MPa. Disposing a semiconductor wafer on the film adhesive of the dicing tape with a film adhesive according to claim 10;
Forming a semiconductor chip by dicing the semiconductor wafer disposed on the film adhesive;
Picking up the semiconductor chip together with the film adhesive;
A step of die-bonding the semiconductor chip on an adherend via the film adhesive;
And a step of thermosetting the film adhesive after the step of die-bonding the semiconductor chip onto an adherend. A semiconductor device obtained by the manufacturing method according to claim 11.

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