TW201531550A - Film-like adhesive, dicing tape with film-like adhesive, method for manufacturing semiconductor device, and semiconductor device - Google Patents

Abstract

Provided are: a film-like adhesive which is capable of relaxing a stress that is caused by expansion difference; a dicing tape with a film-like adhesive; and a method for manufacturing a semiconductor device. The present invention relates to a thermosetting film-like adhesive which contains an acrylic resin, an epoxy resin and conductive particles. The conductive particles contain 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 5-100% by weight; and the thermosetting film-like adhesive has a storage elastic modulus of 5-100 MPa at 150 DEG C after thermal curing.

Description

Film-like adhesive, etched ribbon with film-like adhesive, method for manufacturing semiconductor device, and semiconductor device

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

In the manufacture of a semiconductor device, a method in which a semiconductor element is followed by a metal lead frame or the like (so-called die-bonding method) is developed from a conventional gold-ruthenium eutectic to a method using solder or a resin paste. At present, a method of using a conductive resin paste is applied.

However, the method of using the resin paste has a problem in that conductivity is lowered due to pores, or the thickness of the resin paste is not uniform, thereby contaminating the pad due to overflow of the resin paste. In order to solve such problems, a film-like adhesive containing a polyimide resin is used instead of the resin paste (for example, refer to Patent Document 1).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 6-145639

Therefore, semiconductor devices attach importance to reliability. As tests for evaluating reliability, there are, for example, a temperature cycle test, a pressure cooker test, a moisture absorption reflow test, and the like.

In recent years, a smart type of mobile phone or a laptop computer is often equipped with a thin semiconductor device in order to achieve both performance improvement and thinning of the device. However, semiconductor equipment The thinner the setting, the greater the influence of the stress generated by the difference in the linear expansion of the tantalum wafer and the metal lead frame in the temperature cycle test, and the increase in the adhesion of the bonding agent for bonding the tantalum wafer to the metal lead frame.

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

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

Since the film-like adhesive of the present invention has a storage elastic modulus of 100 MPa or less at 150 ° C after heat curing, the stress caused by the difference in linear expansion can be alleviated, and the defect in the temperature cycle test can be reduced. Further, since the plate-like particles having an aspect ratio of 5 or more are included, the conductive particles can be formed by the surface contact of the plate-like particles. Therefore, the film-like adhesive of the present invention can obtain excellent conductivity as compared with an adhesive containing only spherical particles which form conductive paths by point contact.

The epoxy resin having a bisphenol type skeleton is preferred because the epoxy groups are far apart from each other and the storage elastic modulus after thermal curing is lowered. The epoxy equivalent of the epoxy resin is preferably from 180 g/eq. to 3500 g/eq.

The film-like adhesive of the present invention preferably further contains a phenol resin, and the phenol resin has a hydroxyl equivalent of 200 g/eq. or more. Thereby, the storage elastic modulus after heat hardening can be easily lowered.

The film-like 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 thermal hardening can be lowered low.

The film-like adhesive of the present invention is preferably a low molecular weight acrylic resin containing a functional group reactive with an epoxy group. The weight average molecular weight of the low molecular weight acrylic resin is preferably from 500 to 100,000. The reason for this is that the low molecular weight acrylic resin can be cured, and the storage elastic modulus after heat curing can be lowered.

The film-like adhesive of the present invention preferably further contains a phosphorus-based catalyst. The reason is that the imidazole-based catalyst is introduced into the crosslinked structure, so that the storage elastic modulus after thermal hardening increases, but the phosphorus-based catalyst is not introduced into the crosslinked structure, so that the thermal hardening can be suppressed. Increase in storage elastic modulus.

Moreover, the present invention relates to a method of fabricating a semiconductor device comprising: a step of bonding a semiconductor wafer to a substrate via a film-like adhesive; and a step of adhering the semiconductor wafer to the object to be bonded a step of thermally hardening the film-like adhesive.

Further, the present invention relates to a dicing tape having a film-like adhesive comprising a dicing tape and a thermosetting film-like adhesive disposed on the dicing tape.

Moreover, the present invention relates to a method of fabricating a semiconductor device comprising: a step of disposing a semiconductor wafer on a film-like adhesive attached to a dicing tape of a film-like adhesive; and a semiconductor crystal disposed on a film-like adhesive a step of performing a dicing to form a semiconductor wafer; a step of picking up the semiconductor wafer together with the film-like adhesive; a step of splicing the semiconductor wafer on the adherend via a film-like adhesive; and bonding the semiconductor wafer After the step of crystallizing on the adherend, the step of thermally curing the film-like adhesive is carried out.

Further, the present invention relates to a semiconductor device.

According to the present invention, it is possible to provide a conductive film-like adhesive which can relieve stress caused by a difference in linear expansion, a dicing tape with a film-like adhesive, and a method for producing a semiconductor device.

1‧‧‧Cutting Tape

3‧‧‧membranous adhesive

4‧‧‧Semiconductor wafer

5‧‧‧Semiconductor wafer

6‧‧‧Exposed body

7‧‧‧bonding line

8‧‧‧ Sealing resin

10‧‧‧Cutting tape with film-like adhesive

11‧‧‧Substrate

12‧‧‧Adhesive layer

12a‧‧‧Parts of the adhesive layer corresponding to the attachment portion of the workpiece

12b‧‧‧Other parts of the adhesive layer

61‧‧‧ Attached body with semiconductor wafer

Fig. 1 is a schematic cross-sectional view showing a film-like adhesive.

Fig. 2 is a schematic cross-sectional view showing a dicing tape with a film-like adhesive.

Fig. 3 is a schematic cross-sectional view showing a cleavage zone of a film-like adhesive agent according to a modification.

4 is a schematic cross-sectional view showing a state in which a semiconductor wafer is placed on a dicing tape with a film-like adhesive.

Fig. 5 is a schematic cross-sectional view showing a state in which a semiconductor wafer is singulated.

Fig. 6 is a schematic cross-sectional view showing a member to be attached to a semiconductor wafer.

Fig. 7 is a schematic cross-sectional view showing a semiconductor device.

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

[Embodiment 1]

(membrane adhesive)

As shown in Fig. 1, the form of the film-like adhesive 3 of the first embodiment is a film. The film-like adhesive 3 has thermosetting properties.

Regarding the resin component, the film-like adhesive 3 contains an epoxy resin, a phenol resin, and a high molecular weight acrylic resin. In the first embodiment, the phenol resin functions as a curing agent for the epoxy resin.

The storage elastic modulus at 150 ° C after the film-like adhesive 3 is thermally cured is 5 MPa or more, preferably 20 MPa or more. Since the storage elastic modulus is 5 MPa or more, the wire bonding property can be ensured. On the other hand, the storage elastic modulus of the film-like adhesive 3 at 150 ° C after heat curing is 100 MPa or less. Since the storage elastic modulus is 100 MPa or less, the stress caused by the difference in linear expansion can be alleviated, and the defect in the temperature cycle test can be reduced.

The storage elastic modulus at 150 ° C after thermal hardening refers to the storage elastic modulus at 150 ° C for 1 hour, followed by heating at 200 ° C for 1 hour, thereby thermally hardening at 150 ° C. Specifically, the measurement can be carried out by the method described in the examples.

The storage elastic modulus at 150 ° C after heat hardening can be epoxy by epoxy The amount, the hydroxyl equivalent of the phenol resin, the acid value of the high molecular weight acrylic resin, the acid value of the low molecular weight acrylic resin, the particle diameter of the conductive particles, and the like are controlled. For example, by blending an epoxy resin having a large epoxy equivalent, a phenol resin having a large hydroxyl equivalent, a high molecular weight acrylic resin having a low acid value, and a low molecular weight acrylic resin having a low acid value, blending The conductive particles having a large particle diameter or the like have a reduced storage modulus at 150 ° C after the heat curing.

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 novolak type epoxy resin, and a naphthalene type epoxy resin. Among them, an epoxy resin having a bisphenol type skeleton is preferable because the epoxy groups are far apart from each other and the storage elastic modulus after thermal curing can be lowered. Examples of the epoxy resin having a bisphenol type skeleton include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a 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, still more preferably 400 g/eq. or more. On the other hand, the epoxy equivalent of the epoxy resin is preferably 3,500 g/eq. or less, more preferably 1,500 g/eq. or less, still more preferably 1,000 g/eq. or less, still more preferably 700 g/eq. or less.

Further, the epoxy equivalent of the epoxy resin can be measured by the method specified in JIS K 7236-2009.

The phenol resin functions as a curing agent for an epoxy resin, and examples thereof include a phenol novolak resin, a phenol aralkyl resin, a cresol novolak resin, a third butyl phenol novolak resin, and a nonylphenol system. A novolak type phenol resin such as a novolac resin, a novolac type phenol resin, or a polyoxystyrene such as polyparaxyl styrene.

The hydroxyl equivalent of the phenol resin is preferably 200 g/eq. or more. When it is 200 g/eq. or more, the storage elastic modulus after heat hardening can be easily lowered. On the other hand, the hydroxyl equivalent of the phenol resin is preferably 3,500 g/eq. or less, more preferably 1,500 g/eq. or less, still more preferably 1,000 g/eq. or less, still more preferably 700 g/eq. or less, and particularly preferably 300g/eq. or less.

The blending ratio of the epoxy resin and the phenol resin is preferably, for example, one equivalent of the epoxy group in the epoxy resin component and the hydroxyl group in the phenol resin being 0.5 to 2.0 equivalents. More preferably, the hydroxyl group is 0.8 to 1.2 equivalents. The reason for this is that if the blending ratio of the two is out of the above range, a sufficient hardening reaction is not performed, and the properties of the cured product are easily deteriorated.

The total content of the epoxy resin and the phenol resin in the film-like adhesive 3 is preferably 5% by weight or more, more preferably 8% by weight or more, still more preferably 10% by weight or more. When it is 5% by weight or more, the film-like adhesive 3 after curing can obtain a suitable hardness. Further, 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, still more preferably 15% by weight or less. If it is 30% by weight or less, appropriate conductivity can be obtained.

The weight average molecular weight of the high molecular weight acrylic resin is preferably 200,000 or more, more preferably 300,000 or more, still more preferably 500,000 or more. If it is 200,000 or more, the film-like adhesive 3 after hardening can obtain suitable toughness. 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 the amount is 1,000,000 or less, the solubility in an organic solvent and the workability of the dissolved polymer solution are excellent.

In addition, the weight average molecular weight is measured by GPC (gel permeation chromatography), and is calculated by polystyrene conversion.

The high molecular weight acrylic resin is not particularly limited, and one or two kinds of esters of acrylic acid or methacrylic acid having a linear or branched alkyl group having a carbon number of 30 or less, particularly a carbon number of 4 to 18, may be mentioned. A polymer (acrylic copolymer) or the like having the above composition. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, an isopentyl group, a hexyl group, a heptyl group, and a cyclohexyl group. 2-ethylhexyl, octyl, isooctyl, decyl, isodecyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, ten Octaalkyl, or dodecyl, and the like.

Further, the other monomer forming the polymer (acrylic copolymer) is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, carboxyethyl acrylate, and acrylic acid carboxylate. Various acid anhydride monomers such as valeryl ester, itaconic acid, maleic acid, fumaric acid or crotonic acid, maleic anhydride or itaconic anhydride, 2-hydroxyethyl (meth)acrylate , 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, (meth)acrylic acid Various hydroxyl group-containing monomers such as 10-hydroxydecyl ester, 12-hydroxylauryl (meth)acrylate or (4-hydroxymethylcyclohexyl)-methyl acrylate, styrenesulfonic acid, allylsulfonic acid, 2 -(meth)acrylamide-methyl-2-methylpropanesulfonic acid, (meth)acrylamide, propanesulfonic acid, sulfopropyl (meth)acrylate or (meth)acryloxynaphthalenesulfonic acid A monomer containing a sulfonic acid group or a monomer containing a phosphate group such as 2-hydroxyethyl propylene acrylate.

The high molecular weight acrylic resin preferably contains a functional group reactive with an epoxy group. Thereby, the high molecular weight acrylic resin can be crosslinked with the epoxy resin.

In the high molecular weight acrylic resin, examples of the functional group reactive with the epoxy group include a carboxyl group and a hydroxyl group. Among them, 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, still more preferably 4 mgKOH/g or more. When it is 1 mgKOH/g or more, the crosslinking of the high molecular weight acrylic resin and the epoxy resin becomes suitable, and the film-like adhesive 3 can obtain good cohesive force. 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, still more preferably 30 mgKOH/g or less. When it is 100 mgKOH/g or less, corrosion of the conductive particles can be prevented, and deterioration of conductivity can be prevented.

Further, the acid value can be measured by a titration method as defined in JIS K 0070-1992.

The acid equivalent of the high molecular weight acrylic resin is preferably 560 g/eq. or more, more preferably 1120 g/eq. or more, still more preferably 1870 g/eq. or more. When it is 560 g/eq. or more, corrosion of electroconductive particle can be prevented. On the other hand, the acid of high molecular weight acrylic resin The amount is preferably 56110 g/eq. or less, more preferably 18700 g/eq. or less, still more preferably 14030 g/eq. or less. If it is 56110 g/eq. or less, good cohesive force can be obtained.

Further, the acid equivalent can be obtained from the acid value.

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

In the low molecular weight acrylic resin, examples of the functional group reactive with the epoxy group include a carboxyl group and a hydroxyl group. Among them, 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 still more preferably 50 mgKOH/g or more. When it is 10 mgKOH/g or more, the storage elastic modulus after thermosetting can be easily adjusted to an appropriate range. 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, still more preferably 300 mgKOH/g or less. When it is 1000 mgKOH/g or less, corrosion of the conductive particles can be prevented, and deterioration of conductivity can be prevented.

The acid equivalent of the low molecular weight acrylic resin is preferably 56 g/eq. or more, more preferably 187 g/eq. or more. When it is 56 g/eq. or more, corrosion of the conductive particles can be prevented, and the decrease in conductivity can be prevented. 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. or less. If it is 5610 g/eq. or less, the storage elastic modulus after thermosetting can be easily adjusted to an appropriate range.

The weight average molecular weight of the low molecular weight acrylic resin is preferably 500 or more, more preferably 1,000 or more, still more preferably 1,500 or more. When it is 500 or more, the cohesiveness of the film-like adhesive 3 before hardening can be improved. 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, still more preferably 30,000 or less. If it is 100,000 or less, the storage elastic modulus before curing of the film-like adhesive 3 can be suppressed. l, and get good grain adhesion.

The low molecular weight acrylic resin may, for example, be a structural unit containing a monomer derived from a carboxyl group. Examples of the monomer containing a carboxyl group include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, and maleic acid. Among them, acrylic acid is preferred because of the ease of introduction into the polymer in polymer synthesis.

The low molecular weight acrylic resin may contain other structural units than the structural unit derived from the monomer containing a carboxyl group. As another structural unit, a structural unit derived from styrene, etc. are mentioned, for example. By containing a structural unit derived from styrene, the dispersibility with other compounding ingredients becomes good.

The content of the acrylic resin in the film-like adhesive 3 is preferably 1% by weight or more, more preferably 2% by weight or more, and still more 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, still more preferably 7% by weight or less. If it is 20% by weight or less, appropriate conductivity can be obtained.

When the film-like 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, further preferably 85% by 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, 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 a grain adhesion temperature to obtain good grain adhesion.

The film-like adhesive 3 preferably contains a hardening catalyst. Thereby, thermal hardening can be promoted. The curing catalyst is not particularly limited, and examples thereof include a phosphorus-based catalyst and an imidazole-based catalyst. Among them, a phosphorus-based catalyst is preferred. The reason is that the imidazole-based catalyst is introduced into the cross-linking junction. Therefore, there is a case where the storage elastic modulus after thermal hardening is increased. However, since the phosphorus-based catalyst is not caused to crosslink, the increase in the storage elastic modulus after thermal hardening can be suppressed.

The phosphorus-based catalyst is not particularly limited, and tetraphenylphosphonium tetraphenylphosphonate or tetraphenylphosphonium tetra-p-tolylborate is preferred for reasons of storage stability.

The content of the curing catalyst is preferably 0.1 part by weight or more, more preferably 0.5 part by weight or more, and still more preferably 1 part by weight or more based on 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 based on 100 parts by weight of the epoxy resin. When it is 10 parts by weight or less, appropriate storage stability can be obtained.

The film-like adhesive 3 contains conductive particles. Thereby, conductivity can be imparted. Examples of the conductive particles include gold particles, silver particles, copper particles, and coated particles.

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

The average particle diameter of the conductive particles is not particularly limited, and is preferably 0.001 times or more (thickness of the film-like adhesive 3 × 0.001 or more), more preferably 0.1 times or more, with respect to the thickness of the film-like adhesive 3 . If it is less than 0.001 times, it is difficult to form a conductive path, and the conductivity tends to be unstable. In addition, the average particle diameter of the conductive particles is preferably 1 or less (the thickness of the film-like adhesive 3 or less), more preferably 0.8 times or less, with respect to the thickness of the film-like adhesive 3. If it exceeds 1 time, there is a risk of causing the wafer to rupture.

Further, the average particle diameter of the conductive particles is a value obtained by a photometric particle size distribution meter (manufactured by HORIBA, device name; LA-910).

The specific gravity of the conductive particles is preferably 0.7 or more, and more preferably 1 or more. When it is less than 0.7, the electroconductive particle floats at the time of preparation of an adhesive composition solution (varnish), and the dispersion of electroconductive particle becomes uneven. Further, the specific gravity of the conductive particles is preferably 22 or less, more preferably 21 or less. If it exceeds 22, the conductive particles are likely to sink and the conductive particles are divided. The scatter becomes uneven.

The conductive particles contain plate-like particles.

Examples of the plate-like particles include plate-shaped particles having an aspect ratio of 5 or more. When the aspect ratio is 5 or more, the plate-like particles are easily brought into surface contact with each other to easily form a conductive path. 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, further preferably 70 or less, and particularly preferably 50 or less.

The aspect ratio of the plate-like particles is the ratio of the average long diameter to the average thickness (average long diameter / average thickness).

In the present specification, the average long diameter of the plate-like particles is obtained by observing the cross section of the film-like adhesive 3 by a scanning electron microscope (SEM), and measuring the long diameter of 100 randomly selected plate-like particles. The average value.

Further, the average thickness of the plate-like particles was obtained by observing the cross section of the film-like adhesive 3 by a scanning electron microscope (SEM), and measuring the thickness of 100 randomly selected plate-like particles to obtain an average value.

The average long diameter of the plate-like particles is preferably 0.5 μm or more, and more preferably 1.0 μm or more. When it is 0.5 μm or more, the contact probability of the plate-like particles becomes high and it is easy to conduct.

On the other hand, the average long diameter of the plate-like particles is preferably 50 μm or less, more preferably 30 μm or less. When it is 50 μm or less, it is difficult to cause precipitation of particles in the varnish coating 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 still more 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, preferably 90% by weight or less, more preferably 85% by weight or less.

The conductive particles preferably contain spherical spherical particles.

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

The conductive particles may also contain acicular particles, filamentous particles, or the like.

The content of the conductive particles in the film-like 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, and particularly preferably 80% by weight. More than weight%. If it is less than 30% by weight, there is a tendency that it is difficult to form a conductive path. Further, the content of the conductive particles is preferably 95% by weight or less, more preferably 90% by weight or less, still more preferably 88% by weight or less. If it exceeds 95% by weight, there is a tendency that it is difficult to form a film.

The film-like adhesive 3 may contain, in addition to the above components, a formulation which is usually used for film production, for example, a crosslinking agent.

The film-like adhesive 3 can be produced by a usual method. For example, a solution of an adhesive composition containing the above components is prepared, and a solution of the adhesive composition is applied onto a substrate separator so as to have a specific thickness to form a coating film, and then the coating film is dried. A film-like adhesive 3 can be produced.

The solvent used for the adhesive composition solution is not particularly limited, and is preferably an organic solvent which can uniformly dissolve, knead or disperse the above components. For example, a ketone solvent such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, acetone, methyl ethyl ketone or cyclohexanone, toluene or xylene may be mentioned. The coating method is not particularly limited. Examples of the method of solvent coating include a die coater, a gravure coater, a roll coater, a reverse coater, a notch coater, a tube coater, and screen printing. Wait. Among them, a die coater is preferred in terms of a high uniformity of coating thickness.

As the substrate separator, surface coating can be carried out using a release agent such as polyethylene terephthalate (PET), polyethylene, polypropylene, or a fluorine-based release agent or an acrylic long-chain alkyl ester release agent. Plastic film or paper. Examples of the coating method of the adhesive composition solution include roll coating, screen coating, gravure coating, and the like. Moreover, the drying conditions of the coated film There is no particular limitation. For example, it can be dried at a drying temperature of 70 to 160 ° C for 1 to 5 minutes.

As a method of producing the film-like adhesive 3, for example, a method in which the above components are mixed by a stirrer, and the obtained mixture is subjected to press molding to produce a film-like adhesive 3 is also preferable. Examples of the agitator include a planetary mixer and the like.

The thickness of the film-like adhesive 3 is not particularly limited, but is preferably 5 μm or more, and more preferably 15 μm or more. If it is less than 5 μm, there is a case where a warped semiconductor wafer or a portion which is not in contact with the semiconductor wafer is generated, and the area becomes unstable. Further, the thickness of the film-like adhesive 3 is preferably 100 μm or less, and more preferably 50 μm or less. If it exceeds 100 μm, there is a case where the film-like adhesive excessively overflows due to the load of the die adhesion, thereby contaminating the pad.

The surface roughness (Ra) of the film-like adhesive 3 is preferably from 0.1 to 5,000 nm. If it is less than 0.1 nm, it is difficult to mix. On the other hand, when it exceeds 5000 nm, there is a possibility that the adhesion to the adherend is lowered when the crystal grains are adhered.

The lower the specific resistance of the film-like adhesive 3, the better, for example, 9 × 10 ^-2 Ω ‧ m or less. When it is 9 × 10 ^-2 Ω ‧ m or less, the conductivity is good and it can correspond to a small ‧ high-density package. On the other hand, the specific resistance is preferably 1 × 10 ^-6 Ω ‧ m or more.

The higher the thermal conductivity of the film-like adhesive 3, the better, for example, 0.5 W/m‧K or more. When it is 0.5 W/m‧K or more, heat dissipation is good and it can respond to a small ‧ high-density package. On the other hand, if it is less than 0.5 W/m‧K, heat dissipation is inferior, and heat accumulation causes deterioration of electrical conductivity.

The tensile storage elastic modulus at 120 ° C of the film-like adhesive 3 is preferably 10 MPa or less, more preferably 5 MPa or less. When the pressure is 10 MPa or less, the fluidity of the film-like adhesive 3 in the vicinity of the heat curing temperature is high, and it is easy to cause the pores to disappear by heating under pressure. The tensile storage elastic 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, it is difficult for the film-like adhesive 3 to overflow.

The tensile storage elastic modulus at 120 ° C can be measured by the following method.

Determination of tensile storage elastic modulus at 120 ° C

A strip of a measuring piece having a length of 30 mm, a width of 10 mm, and a thickness of 400 μm was cut out from the film-like adhesive 3. For the measurement piece, a fixed viscoelasticity measuring apparatus (RSA-II, manufactured by Rheometric Scientific Co., Ltd.) was used to stretch the chuck width of 22.6 mm and 0 ° C to 200 ° C at a frequency of 1 Hz and a temperature increase rate of 10 ° C/min. The elastic modulus was stored for measurement.

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

The film-like adhesive 3 is used for the manufacture of a semiconductor device. Among them, it can be particularly preferably used for the manufacture of power semiconductor devices. Specifically, it is used as a module adhesive film for adhering (die bonding) a semiconductor substrate such as a lead frame to a semiconductor wafer. Examples of the adherend include a lead frame, an interposer, and a semiconductor wafer. Among them, a lead frame is preferred.

The film-like adhesive 3 is preferably used in the form of a dicing tape with a film-like adhesive. When it is used in this form, the semiconductor wafer attached to the state of the dicing tape with the film-like adhesive can be operated. Therefore, the chance of operating the semiconductor wafer alone can be reduced, and the operability is good. Therefore, even in the case of a thin semiconductor wafer in recent years, it is possible to operate satisfactorily.

[Cutting tape with film-like adhesive]

The dicing tape with a film-like adhesive will be described.

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

As shown in FIG. 3, the dicing tape 10 with a film-like adhesive may have a film-like adhesive 3 formed only on a portion where the workpiece (semiconductor wafer 4 or the like) is attached.

The base material 11 is a strength matrix of the dicing tape 10 with a film-like adhesive, and is preferably one having ultraviolet ray permeability. Examples of the substrate 11 include low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, and block copolymer polypropylene. Polyolefins such as polypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionic polymer resin, ethylene-(meth)acrylic copolymer, ethylene-(meth)acrylate (none , alternating) copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, polyurethane, polyethylene terephthalate, polyethylene naphthalate and other polyester, polycarbonate Esters, polyimine, polyetheretherketone, polyimine, polyetherimine, polyamine, wholly aromatic polyamine, polyphenylene sulfide, aromatic polyamine (paper), glass, Glass cloth, fluororesin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, polyoxyxylene resin, metal (foil), paper, and the like.

The surface of the substrate 11 may be subjected to conventional surface treatment such as chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, ionizing radiation treatment, or the like in order to improve adhesion to the adjacent layer, retention, and the like. Physical treatment, coating treatment using a primer (for example, an adhesive substance described below).

The thickness of the substrate 11 is not particularly limited and can be appropriately determined, and is usually about 5 to 200 μm.

The adhesive to be used for the formation of the adhesive layer 12 is not particularly limited, and for example, a usual pressure-sensitive adhesive such as an acrylic adhesive or a rubber-based adhesive can be used. As a pressure-sensitive adhesive, it is preferable to use a polymer based on an acrylic polymer in terms of avoiding the cleansing property of an organic solvent such as ultrapure water or alcohol by using a contaminated electronic component such as a semiconductor wafer or glass. Acrylic adhesive for the substance.

Examples of the acrylic polymer include alkyl (meth)acrylate (for example, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, second butyl ester, and third butyl group). Ester, amyl ester, isoamyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, decyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester , tridecyl ester, fourteen Alkyl esters having a carbon number of from 1 to 30, especially a linear or branched alkyl ester having from 4 to 18 carbon atoms, such as an alkyl ester, a hexadecyl ester, an octadecyl ester or an eicosyl ester. One or two or more kinds of acrylic polymers such as a cycloalkyl (meth)acrylate (for example, a cyclopentyl ester or a cyclohexyl ester) as a monomer component. In addition, the term "(meth)acrylate" means an acrylate and/or a methacrylate, and the (meth) of this invention is all the same meaning.

The acrylic polymer may also be modified for cohesive strength, heat resistance, etc., and optionally contains a unit corresponding to another monomer component copolymerizable with the above alkyl (meth)acrylate or cycloalkyl ester. Examples of the monomer component include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like. Carboxyl group-containing monomer; anhydride monomer such as maleic anhydride or itaconic anhydride; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate , 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (meth)acrylic acid a hydroxyl group-containing monomer such as (4-hydroxymethylcyclohexyl)methyl ester; styrenesulfonic acid, allylsulfonic acid, 2-(methyl)propenylamine-2-methylpropanesulfonic acid, (methyl a sulfonic acid group-containing monomer such as acrylamide propyl sulfonic acid, sulfopropyl (meth) acrylate, (meth) propylene phthaloxy naphthalene sulfonic acid, or phosphoric acid containing 2-hydroxyethyl propylene phthalate Base monomer; acrylamide, acrylonitrile, and the like. One or two or more kinds of these copolymerizable monomer components can be used. The amount of such copolymerizable monomers used is preferably 40% by weight or less based on the total monomer components.

Further, the acrylic polymer may contain a polyfunctional monomer or the like as a monomer component for copolymerization as needed in order to carry out crosslinking. Examples of the polyfunctional monomer include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and new Pentandiol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate Ester, epoxy (meth) acrylate, (meth) acrylate polyester, (meth) acrylate urethane, and the like. Polyfunctional monomers One type or two or more types can also be used. The amount of the polyfunctional monomer to be used is preferably 30% by weight or less based on the total monomer component in terms of adhesion characteristics and the like.

The acrylic polymer can be obtained by supplying a single monomer or a mixture of two or more kinds of monomers to polymerization. The polymerization may also be carried out in any one of solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and the like. In terms of preventing contamination of the cleaned adherend, etc., it is preferred that the content of the low molecular weight substance is small. In this respect, the number average molecular weight of the acrylic polymer is preferably 300,000 or more, and more preferably about 400,000 to 3,000,000.

Further, in order to increase the number average molecular weight of the acrylic polymer or the like as the base polymer, the above-mentioned adhesive may suitably employ an external crosslinking agent. A specific method of the external crosslinking method is a method in which a reaction is carried out by adding a so-called crosslinking agent such as a polyisocyanate compound, an epoxy compound, an aziridine compound or a melamine-based crosslinking agent. In the case of using an external crosslinking agent, the amount of the external crosslinking agent to be used is appropriately determined depending on the balance with the base polymer to be crosslinked, and further depending on the use as the adhesive. In general, it is preferably formulated in an amount of about 5 parts by weight or less, and further preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the base polymer. Further, in the adhesive, in addition to the above components, additives such as various conventionally known adhesion-imparting agents and anti-aging agents may be used as needed.

The adhesive layer 12 can be formed by a radiation hardening type adhesive. The radiation-curable adhesive can increase the degree of crosslinking by irradiation with radiation such as ultraviolet rays, and it is easy to lower the adhesion.

The difference in adhesion to the other portions 12b can be set by irradiating only the portion 12a of the adhesive layer 12 shown in Fig. 2 corresponding to the attached portion of the workpiece. In this case, the portion 12b formed by the uncured radiation-curable adhesive adheres to the film-like adhesive 3, and the holding force at the time of crystal cutting can be ensured.

Further, the film-like adhesive 3 shown in Fig. 3 is superposed on the radiation-curable adhesive. The layer 12 is hardened, whereby the above-mentioned portion 12a in which the adhesive force is remarkably lowered can be formed. In this case, the wafer ring can be fixed to the portion 12b formed by the uncured radiation-curable adhesive.

That is, in the case where the adhesive layer 12 is formed by the radiation-curable adhesive, it is preferable to perform the above-described portion 12a such that the adhesive force of the portion 12a of the adhesive layer 12 is the adhesion of the other portion 12b. Radiation exposure.

The radiation-curable adhesive can be a functional group having a radiation curable property such as a carbon-carbon double bond, and is not particularly limited as long as it exhibits adhesiveness. The radiation-curable adhesive agent is, for example, an additive type in which a radiation-curable monomer component or an oligomer component is blended in a usual pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive. Radiation hardening adhesive.

Examples of the radiation curable monomer component to be blended include a urethane oligomer, a (meth)acrylic acid urethane, a trimethylolpropane tri(meth)acrylate, and the like. Methylol methane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexa(meth)acrylate, 1, 4-butanediol di(meth)acrylate or the like. In addition, examples of the radiation curable oligomer component include various oligomers such as a urethane type, a polyether type, a polyester type, a polycarbonate type, and a polybutadiene type, and the molecular weight thereof is 100. The range of ~30000 or so is suitable. The amount of the radioactive monomer component or the oligomer component can be appropriately determined depending on the type of the adhesive layer to reduce the adhesion of the adhesive layer. In general, it is, for example, 5 to 500 parts by weight, preferably 40 to 150 parts by weight, per 100 parts by weight of the base polymer such as the acrylic polymer constituting the pressure-sensitive adhesive.

Further, as the radiation-curable adhesive, in addition to the above-described added radiation-curable adhesive, it may be used in a polymer branch or a main chain or a carbon-carbon double bond at the end of the main chain. A type of radiation hardening type adhesive is used as a base polymer. About the intrinsic type of radiation hardening type adhesive, since it does not need to be contained as a low molecular weight Since the oligomer component or the like is not contained in a large amount, it is preferable since the oligomer component does not move in the adhesive over time, and an adhesive layer having a stable layer structure can be formed.

The base polymer having a carbon-carbon double bond may be a carbon-carbon double bond and has adhesiveness, and is not particularly limited. As such a base polymer, it is preferred to use an acrylic polymer as a basic skeleton. The basic skeleton of the acrylic polymer may, for example, be an acrylic polymer exemplified above.

The introduction method of the carbon-carbon double bond to the above acrylic polymer is not particularly limited, and various methods can be employed, and introduction of a carbon-carbon double bond into a polymer branch is easy in molecular design. For example, a method in which an acrylic polymer and a monomer having a functional group are copolymerized in advance and then reacts with the functional group while maintaining the radiation curability of the carbon-carbon double bond The compound having a functional group and a carbon-carbon double bond is subjected to a condensation or addition reaction.

Examples of the combination of the functional groups include a carboxylic acid group and an epoxy group, a carboxylic acid group and an aziridine group, a hydroxyl group and an isocyanate group. Among the combinations of these functional groups, in view of easiness of the reaction, a combination of a hydroxyl group and an isocyanate group is preferred. Further, as long as a combination of the above-mentioned acrylic polymer having a carbon-carbon double bond is produced by a combination of the functional groups, the functional group may be located on either side of the acrylic polymer and the above compound, Preferably, the acrylic polymer has a hydroxyl group, and the above compound has an isocyanate group. In this case, examples of the isocyanate compound having a carbon-carbon double bond include methacryl oxime isocyanate, 2-methacryloxyethyl isocyanate, m-isopropenyl-α, α-dimethyl Alkyl benzyl isocyanate or the like. Further, as the acrylic polymer, a monomer having a hydroxyl group as exemplified above, an ether compound of 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether or diethylene glycol monovinyl ether, or the like can be used. Aggregated.

The above-mentioned intrinsic type of radiation hardening type adhesive can be used alone for the above carbon-carbon double The base polymer (especially the acrylic polymer) of the bond may be blended with the radiation curable monomer component or oligomer component to the extent that the properties are deteriorated. The radiation curable oligomer component or the like is usually in the range of 30 parts by weight, preferably 0 to 10 parts by weight, per 100 parts by weight of the base polymer.

In the radiation curable adhesive, when it is cured by ultraviolet rays or the like, a photopolymerization initiator is contained. As the photopolymerization initiator, for example, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)one, α-hydroxy-α,α'-dimethylacetophenone can be exemplified. , an α-keto alcohol compound such as 2-methyl-2-hydroxypropiophenone or 1-hydroxycyclohexyl phenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylbenzene Ketone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2- An acetophenone-based compound such as phenylpropanol-1; a benzoin ether compound such as benzoin ethyl ether, benzoin isopropyl ether, and fennel methyl ether; a ketal compound such as benzoin dimethyl ketal; 2-naphthoquinone Aromatic sulfonium chloride compound such as chlorine; photoactive lanthanide compound such as 1-benzophenone-1,1-propanedione-2-(o-ethoxycarbonyl)anthracene; benzophenone, benzamidine benzoic acid a benzophenone compound such as 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4- Thioxanthone such as dimethyl thioxanthone, isopropyl thioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone a compound; camphorquinone; a halogenated ketone; a mercaptophosphine oxide; a mercapto phosphate. The amount of the photopolymerization initiator to be added is, for example, about 0.05 to 20 parts by weight based on 100 parts by weight of the base polymer such as the acrylic polymer constituting the pressure-sensitive adhesive.

In addition, as the radiation-curable adhesive, an addition polymerizable compound having two or more unsaturated bonds and an alkoxydecane having an epoxy group disclosed in JP-A-60-196956, for example, may be mentioned. A photopolymerizable compound, a rubber-based adhesive such as a photopolymerization initiator such as a carbonyl compound, an organic sulfur compound, a peroxide, an amine or a phosphonium salt compound, or an acrylic adhesive.

In the radiation-curable adhesive layer 12, a compound which is colored by radiation irradiation may be contained as needed. Coloring by radiation The compound is contained in the adhesive layer 12, whereby only the portion irradiated with radiation can be colored. The compound colored by radiation irradiation is a colorless or pale color before radiation irradiation, but a compound which becomes colored by radiation irradiation, and examples thereof include a leuco dye. The ratio of use of the compound colored by radiation irradiation can be appropriately set.

The thickness of the adhesive layer 12 is not particularly limited, and is preferably about 1 to 50 μm in terms of prevention of defects on the cut surface of the wafer or fixation of the film-like adhesive 3. It is preferably 2 to 30 μm, and more preferably 5 to 25 μm.

The film-like adhesive 3 of the dicing tape 10 with a film-like adhesive is preferably protected by a separator (not shown). The separator has a function as a protective film-like adhesive 3 up to a practical protective material. The separator is peeled off when the workpiece is attached to the film-like adhesive 3. As the separator, a plastic film coated with a release agent such as polyethylene terephthalate (PET), polyethylene, polypropylene, or a fluorine-based release agent or a long-chain alkyl acrylate release agent may be used. Or paper, etc.

The dicing tape 10 with a film-like adhesive can be produced by a usual method. For example, the dicing tape 10 with a film-like adhesive can be produced by laminating the adhesive layer 12 of the dicing tape 1 and the film-like adhesive 3.

The peeling force of the film-like adhesive 3 from the dicing tape 1 at a peeling temperature of 25 ° C and a peeling speed of 300 mm/min is preferably 0.01 to 3.00 N / 20 mm. If it is less than 0.01 N/20 mm, there is a flaw in wafer breakage during dicing. On the other hand, if it exceeds 3.00 N/20 mm, picking tends to be difficult.

[Method of Manufacturing Semiconductor Device]

A method of manufacturing a semiconductor device will be described.

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

Examples of the pressure bonding method include pushing by a pressing mechanism such as a pressure roller. The method of pressing, etc.

The crimping temperature (attachment temperature) is preferably 35 ° C or more, more preferably 50 ° C or more. The lower limit of the crimping temperature is preferably lower, preferably 80 ° C or lower, more preferably 50 ° C or lower, and still more preferably 45 ° C or lower. The thermal influence on the semiconductor wafer 4 can be prevented by the pressure bonding at a low temperature, and the warpage of the semiconductor wafer 4 can be suppressed.

Further, the pressure is preferably from 1 × 10 ⁵ Pa to 1 × 10 ⁷ Pa, more preferably from 2 × 10 ⁵ Pa to 8 × 10 ⁶ Pa.

Then, as shown in FIG. 5, dicing of the semiconductor wafer 4 is performed. That is, the semiconductor wafer 4 is cut into a specific size to be singulated to cut out the semiconductor wafer 5. The dicing system is carried out according to the usual method. Further, in this step, for example, a cutting method called a full cut which cuts into the film-forming adhesive tape 10 may be employed. The dicing apparatus used in this step is not particularly limited, and those known in the art can be used. Further, since the semiconductor wafer 4 is subsequently fixed by the dicing tape 10 with a film-like adhesive, it is possible to suppress wafer defects or wafer breakage, and to suppress breakage of the semiconductor wafer 4.

In order to peel off the semiconductor wafer 5 which is subsequently fixed to the dicing tape 10 with the film-like adhesive, the semiconductor wafer 5 is picked up. The method of picking up is not particularly limited, and various methods known in the prior art can be employed. For example, a method in which the semiconductor wafer 5 is topped by a needle and the semiconductor wafer 5 is picked up by a pick-up device by a needle is attached to the side of the dicing tape 10 of the film-like adhesive.

Here, in the case where the adhesive layer 12 is of an ultraviolet curing type, the pickup is performed by irradiating the adhesive layer 12 with ultraviolet rays. Thereby, the adhesive force of the adhesive layer 12 to the film-like adhesive 3 is lowered, and peeling of the semiconductor wafer 5 becomes easy. As a result, it is possible to pick up without damaging the semiconductor wafer 5. The conditions such as the irradiation intensity and the irradiation time at the time of ultraviolet irradiation are not particularly limited, and may be appropriately set as necessary.

As shown in FIG. 6, the semiconductor wafer 5 picked up is then fixed to the adherend 6 via the film-like adhesive 3, and the adherend 61 with the semiconductor wafer is obtained. Semiconductor wafer The adherend 61 includes a bonded body 6, a film-like adhesive 3 disposed on the adherend 6, and a semiconductor wafer 5 disposed on the film-like adhesive 3.

The die adhesion temperature is preferably 80 ° C or more, more preferably 100 ° C or more, and still more preferably 130 ° C or more. Further, the die adhesion temperature is preferably 170 ° C or lower, more preferably 160 ° C or lower. The warpage after the adhesion of the crystal grains can be prevented by setting it to 170 ° C or lower.

Then, the film-like adhesive 3 is thermally cured by heating the adherend 61 with the semiconductor wafer, and the semiconductor wafer 5 and the adherend 6 are adhered. It is preferable that the film-like adhesive 3 is thermally cured by heating the adherend 61 with a semiconductor wafer under pressure. By thermally curing the film-like adhesive 3 under pressure, the pores existing between the film-like adhesive 3 and the adherend 6 can be eliminated, and the film-like adhesive 3 can be ensured to be in contact with the adherend 6. The area.

As a method of heating under pressure, for example, a method of heating the adherend 61 attached to the semiconductor wafer attached to the chamber filled with the inert gas may be mentioned.

The pressure in the pressurized environment 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. When it is 0.5 kg/cm ² or more, the pores existing between the film-like adhesive 3 and the adherend 6 can be easily eliminated. Pressurized environment of the pressure is preferably 20kg / cm ² (1.96MPa) or less, more preferably 18kg / cm (1.77MPa) ² or less, and further preferably 15kg / cm (1.47MPa) ² or less. When it is 20 kg/cm ² or less, the overflow of the film-like adhesive 3 caused by excessive pressurization can be suppressed.

The heating temperature at the time of heating under pressure is preferably 80 ° C or higher, more preferably 100 ° C or higher, further preferably 120 ° C or higher, and particularly preferably 170 ° C or higher. When it is 80 ° C or more, the film-like adhesive 3 can be made to have an appropriate hardness, and the pores can be effectively eliminated by press curing.

The heating temperature is preferably 260 ° C or lower, more preferably 200 ° C or lower, more preferably 180 ° C or lower. When it is 260 ° C or less, decomposition of the film-like adhesive 3 before hardening can be prevented.

The heating time is preferably 0.1 hour or longer, more preferably 0.2 hour or longer, and still more preferably 0.5 hour or longer. If it is 0.1 hour or more, the effect of pressurization can be fully obtained. The heating time is preferably 24 hours or shorter, more preferably 3 hours or shorter, and still more preferably 1 hour or shorter.

Then, a wire bonding step of electrically connecting the front end of the terminal portion (internal lead) of the adherend 6 to the electrode pad (not shown) on the semiconductor wafer 5 by the bonding wire 7 is performed. As the bonding wire 7, for example, a gold wire, an aluminum wire, a copper wire, or the like can be used. The temperature at the time of 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. Further, the heating time is performed for several seconds to several minutes (for example, one second to one minute). The wiring is performed by using the vibration energy of the ultrasonic waves and the pressure-bonding energy by applying pressure in a state where the wiring is heated so as to be within the above temperature range.

Then, a sealing step of sealing the semiconductor wafer 5 by the sealing resin 8 is performed. This step is performed to protect the semiconductor wafer 5 or the bonding wires 7 mounted on the bonding body 6. This step is carried out by molding the resin for sealing in 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.

The seal may be further heated (post hardening step) as needed. Thereby, the sealing resin 8 which is insufficiently hardened can be completely hardened in the sealing step. The heating temperature can be set as appropriate.

As described above, in the first embodiment, the semiconductor wafer 5 is bonded to the adherend 6 via the film-like adhesive 3, and the semiconductor wafer 5 is bonded to the adherend 6. After the step, a semiconductor device is manufactured by the method of the step of thermally curing the film-like adhesive 3.

More specifically, the method of the first embodiment includes a step of disposing the semiconductor wafer 4 on the film-like adhesive 3 of the dicing tape 10 with a film-like adhesive; and disposing the film-like adhesive 3 a step of forming a semiconductor wafer 5 by dicing the semiconductor wafer 4 thereon; a step of picking up the semiconductor wafer 5 together with the film-like adhesive 3; and bonding the semiconductor wafer 5 to the adherend via the film-like adhesive 3 The step of 6; and the step of thermally hardening the film-like adhesive 3 after the step of bonding the semiconductor wafer 5 to the adherend 6 is performed.

The first embodiment has been described above.

[Embodiment 2]

(membrane adhesive)

The second embodiment differs from the first embodiment in the composition of the film-like adhesive 3.

The film-like adhesive 3 of the second embodiment includes an epoxy resin, a high molecular weight acrylic resin, and a low molecular weight acrylic resin containing a functional group reactive with an epoxy group. In the second embodiment, the low molecular weight acrylic resin functions as a curing agent for the epoxy resin. Therefore, in the second embodiment, the phenol resin may not be formulated.

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

The content of the epoxy resin in the film-like adhesive 3 is preferably 1% by weight or more, more preferably 2% by weight or more, still more preferably 3% by weight or more. When it is 1% by weight or more, a suitable cured product can be obtained. Further, the content of the epoxy resin is preferably 15% by weight or less, more preferably 10% by weight or less, still more preferably 7% by weight or less. If it is 15% by weight or less, appropriate conductivity can be obtained.

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 reactive with an epoxy group. Examples of the functional group reactive with the epoxy group include a carboxyl group and a hydroxyl group. Among them, a carboxyl group is preferred because of its high reactivity with an epoxy group.

A suitable acid value, acid equivalent weight, weight average molecular weight, and the like 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-like adhesive 3 is preferably 1% by weight or more, more preferably It is 5% by weight or more, 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, still more preferably 15% by weight or less. If it is 20% by weight or less, appropriate conductivity can be obtained.

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, still more preferably 40% by weight or more. When it is 20% by weight or more, it is possible to prevent the film-like adhesive 3 from being excessively melted at the temperature at the time of die adhesion, and it is possible to suppress the overflow of the film-like adhesive 3. 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, still more preferably 60% by weight or less. When it is 98% by weight or less, appropriate conductivity can be obtained.

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

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

The second embodiment has been described above.

[Examples]

Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the following examples as long as the scope of the invention is not exceeded.

The components used in the examples will be described.

Teisan resin SG-70L: Teisan resin SG-70L manufactured by Nagase chemteX (stock) (acrylic copolymer containing carboxyl group and hydroxyl group, Mw: 900,000, acid value: 5 mgKOH/g, acid equivalent: 11222 g/eq.)

Paracron W-248E: Paracron W-248E manufactured by Kokusai Industrial Co., Ltd. (Acrylic resin containing hydroxyl group, Mw: 450,000, acid value: 8.5 mgKOH/g, acid equivalent: 6601 g/eq.)

ARUFON UC-3510: ARUFON UC-3510 manufactured by East Asia Synthetic Co., Ltd. (acrylic resin containing carboxyl group, Mw: 2000, acid value: 70 mgKOH/g, acid equivalent: 802 g/eq.)

ARUFON UC-3080: ARUFON UC-3080 manufactured by East Asia Synthetic 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 Co., Ltd. (epoxy resin with bisphenol type skeleton, epoxy equivalent 184g/eq.~194g/eq.)

EXA-4850-150: EPICLON EXA-4850-150 manufactured by DIC Co., Ltd. (epoxy resin with bisphenol type skeleton, epoxy equivalent 450 g/eq.)

JER1001: JER1001 manufactured by Mitsubishi Chemical Co., Ltd. (epoxy resin with bisphenol type skeleton, epoxy equivalent 450g/eq.~500g/eq.)

JER1004: JER1004 manufactured by Mitsubishi Chemical Co., Ltd. (epoxy resin with bisphenol type skeleton, epoxy equivalent 875g/eq.~975g/eq.)

HP-4032D: EPICLON HP-4032D manufactured by DIC (Epoxy resin with naphthalene type skeleton, epoxy equivalent 136g/eq.~148g/eq.)

EPPN-501HY: EPPN-501HY of Nippon Chemical Co., Ltd. (epoxy resin with polyfunctional backbone, epoxy equivalent 163g/eq.~175g/eq.)

MEH-7851SS: MEH-7851SS manufactured by Minghe Chemical Co., Ltd. (phenol resin, hydroxyl equivalent: 201g/eq.~205g/eq.)

MEH-7851-4H: MEH-7851-4H manufactured by Minghe Chemical Co., Ltd. (phenol resin, hydroxyl equivalent 235g/eq.~245g/eq.)

MEH-8000H: MEH-8000H manufactured by Minghe Chemical Co., Ltd. (phenol resin, hydroxyl equivalent weight 139g/eq.~143g/eq.)

TPP-K: TPP-K (tetraphenylphosphonium tetraphenylborate) manufactured by Beixing Chemical Co., Ltd.

1200YP: 1200YP (flaky copper powder, average grain) manufactured by Mitsui Mining & Mining Co., Ltd. 3.5μm diameter, aspect ratio: 10, specific gravity 8.9)

EHD: EHD manufactured by Mitsui Mining & Mining Co., Ltd. (silver powder, spherical, average particle size 0.7 μm, specific gravity 10.5)

[Production of film-like adhesive and etched tape with film-like adhesive]

(Examples 1 to 7 and Comparative Example 1)

The components and the solvent (methyl ethyl ketone) described in Table 1 were placed in a stirred tank of a mixing stirrer (HM-500 manufactured by KEYENCE) according to the mixing ratio described in Table 1, and stirred in a stirring mode. minute. The obtained varnish was applied to a release-treated film (MRA50 manufactured by Mitsubishi Resin Co., Ltd.) by a die coater, and then dried to prepare a film-like adhesive having a thickness of 30 μm.

The film-like adhesive obtained was cut into a circular shape having a diameter of 230 mm, and attached to an adhesive layer of a dicing tape (P2130G manufactured by Nitto Denko Co., Ltd.) at 25 ° C to form a film. The cleavage zone of the agent.

[Mirror 矽 wafer fabrication]

A mirror-finished wafer was produced by polishing using a back grinder (DFG-8560 manufactured by DISCO) and a thickness of 0.1 mm in a silicon wafer (manufactured by Shin-Etsu Chemical Co., Ltd., thickness: 0.6 mm).

[Evaluation]

The following evaluation was performed about the obtained film-like adhesive and the film-forming adhesive film-forming adhesive. The results are shown in Table 1.

(Storage modulus of elasticity at 150 ° C after thermal hardening)

The film-like adhesive was superposed until the thickness of the film-like adhesive became 500 μm. Thereafter, the mixture was heated at 140 ° C for 1 hour, and further heated at 200 ° C for 1 hour to be thermally hardened. Then, it was cut into a short strip having a length of 22.5 mm (measured length) and a width of 10 mm by a cutting knife, and was measured at a temperature of -50 ° C to 300 ° C using a solid viscoelasticity measuring apparatus (RSAII, manufactured by Rheometric Scientific Co., Ltd.). Store the elastic modulus. The measurement condition is set to frequency 1 Hz, heating rate 10 ° C / min. The value at 150 ° C at this time was taken as the measured value of the storage elastic modulus at 150 ° C after the heat curing.

(temperature cycle evaluation)

The mirror-like wafer is bonded to the film-like adhesive surface of the dicing tape with a film-like adhesive. The bonding system was carried out using a wafer bonding machine (manufactured by Nitto Seiki Co., Ltd.) MA-3000III at a bonding speed of 10 mm/min and a bonding temperature of 70 °C. Then, the crystal was cut by a crystal cutter to obtain a film of 5 mm × 5 mm film-like adhesive. Thereafter, the wafer die with the film-like adhesive was adhered to a copper lead frame (manufactured by Dainippon Printing Co., Ltd., product name: QFN32, 64) by a die bonder. The grain adhesion conditions were set to temperature: 150 ° C, holding time: 0.5 seconds, and pressure: 0.5 MPa. Thereafter, the film was kept at 140 ° C for 1 hour, and then heated at 200 ° C for 1 hour to thermally cure the film-like adhesive to obtain a package for temperature cycle evaluation. For 10 packages, a 1000 cycle thermal cycle test was performed at a temperature of -55 ° C to 150 ° C. The test was carried out in accordance with JEDEC Standard 22-A104C Condition H.

After the thermal cycle test, 10 packages were observed by an ultrasonic microscope, and it was judged that the peeling of the wafer was confirmed to be ×, and the case where all of the 10 packages were not confirmed to be peeled off was judged as ○.

[Comprehensive judgment]

The case where all of the following conditions are satisfied is judged as ○, and the case where any one is not satisfied is judged as ×.

Condition (1): The storage elastic modulus at 150 ° C after thermal hardening is 5 MPa to 100 MPa.

Condition (2): The result of the temperature cycle evaluation was ○.

3‧‧‧membranous adhesive

Claims (12)

A thermosetting type film-like adhesive comprising an acrylic resin, an epoxy resin, and conductive particles, wherein the conductive particles include plate-like particles having an aspect ratio of 5 or more, and the plate is 100% by weight of the conductive particles. The content of the particles is 5% by weight to 100% by weight, and the storage elastic modulus of the film-like adhesive at 150 ° C after heat curing is 5 MPa to 100 MPa. The film-like adhesive of claim 1, wherein the epoxy resin has a bisphenol type skeleton. The film-like adhesive of claim 1, wherein the epoxy resin has an epoxy equivalent of from 180 g/eq. to 3500 g/eq. The film-like adhesive of claim 1, which further comprises a phenol resin, and the phenol resin has a hydroxyl equivalent of 200 g/eq. or more. The film-like adhesive agent of claim 1, wherein the acrylic resin comprises a high molecular weight acrylic resin having a weight average molecular weight of 200,000 to 1,000,000. The film-like adhesive according to claim 1, wherein the acrylic resin comprises a low molecular weight acrylic resin having a weight average molecular weight of 500 to 100,000, and the low molecular weight acrylic resin contains a functional group reactive with an epoxy group. The film-like adhesive of claim 1, which further comprises a phosphorus-based catalyst. A method of manufacturing a semiconductor device, comprising: a step of adhering a semiconductor wafer to a substrate via a film-like adhesive according to any one of claims 1 to 7; and bonding the semiconductor wafer to the semiconductor substrate After the step on the body, the step of thermally curing the film-like adhesive is carried out. A semiconductor device obtained by the manufacturing method of claim 8. A dicing tape with a film-like adhesive comprising a dicing tape and a thermosetting film-like adhesive disposed on the dicing tape, wherein the film-like adhesive comprises an acrylic resin, an epoxy resin, and a conductive film 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% by weight to 100% by weight, and the film-like adhesive is thermally hardened. The storage elastic modulus at 150 ° C is 5 MPa to 100 MPa. A method of manufacturing a semiconductor device, comprising: arranging a semiconductor wafer on the film-like adhesive of a dicing tape attached to a film-like adhesive of claim 10; and arranging the above-mentioned film-like adhesive a step of dicing a semiconductor wafer to form a semiconductor wafer; a step of picking up the semiconductor wafer together with the film-like adhesive; and a step of adhering the semiconductor wafer to the adherend via the film-like adhesive; and After the step of adhering the semiconductor wafer to the adherend, the step of thermally curing the film-like adhesive is performed. A semiconductor device obtained by the manufacturing method of claim 11.