JP2000106372A - Both-sided adhesive film, organic board for mounting semiconductor and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low elasticity both-sided adhesive film for bonding a semiconductor chip to an organic board for mounting a semiconductor having significantly different coefficient of thermal expansion, and an organic board for mounting a semiconductor and a semiconductor device, in which adhesion between a core material and an adhesive layer, reliability and environmental safety, e.g. temperature cycle resistance and reflow resistance, are employed. SOLUTION: In a both-sided adhesive film for electronic part where adhesive layers 11 are formed on the opposite sides of a core material 12, the core material 12 is a porous film of heat resistant resin containing no halogen atom or a porous film of heat resistant resin having surface tension of 20 mN/m or above. The both-sided adhesive film is provide at the semiconductor chip mounting part of an organic board to produce an organic board for mounting a semiconductor. A semiconductor chip 2 is bonded to the organic board for mounting a semiconductor through the both-sided adhesive film thus obtaining a semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided adhesive film and a semiconductor mounting organic substrate suitably used for manufacturing a semiconductor device, and a semiconductor device using them.

[0002]

2. Description of the Related Art When a semiconductor chip is mounted on an organic substrate for mounting a semiconductor, an epoxy or polyimide adhesive called a die bonding paste is used.
However, a thermal stress is generated due to a mismatch in expansion coefficient between the semiconductor chip and the organic substrate for mounting the semiconductor, and furthermore, the motherboard on which the semiconductor device comprising the semiconductor chip is mounted. It causes defects such as cracks in the soldered part. To alleviate such thermal stress, a low elasticity adhesive is effective.

The thickness of the adhesive for relieving thermal stress must be an appropriate thickness designed by simulation or the like, and a film-like adhesive is used to secure the thickness accuracy. ing. In the assembly process of a semiconductor device, a film-like adhesive is used because of its easy handling and a dry process.

[0004] On the other hand, when the solder reflow treatment is performed in a state where the adhesive or the semiconductor mounting substrate has absorbed moisture, a so-called reflow crack that causes swelling due to the vapor pressure of the absorbed moisture is caused. In order to prevent reflow cracks, it is effective to reduce the amount of moisture absorbed by the adhesive, improve the adhesive strength at the reflow temperature, and reduce the generated vapor pressure.

[0005] Such an adhesive having low elasticity and excellent reflow crack resistance is disclosed in, for example, JP-A-4-363032.
JP, JP-A-9-321084, JP-A-10-210
No. 22325.

[0006]

The adhesives described in these publications use a stretched porous film of polytetrafluoroethylene as a core material in terms of heat resistance, hygroscopicity, elastic modulus and the like, and are bonded to both surfaces thereof. It is an adhesive film on which an agent layer is formed. However, since polytetrafluoroethylene has a remarkably low surface tension, it has poor adhesion to the adhesive layer. Therefore, it is necessary to impregnate the core material with an adhesive or to perform a surface treatment (hydrophilic treatment) on the core material. In addition, polytetrafluoroethylene may generate highly toxic hydrogen fluoride when thermally decomposed with other hydrocarbon compounds.

On the other hand, thermosetting resins such as epoxy resins, BT (bismaleimide triazine) resins, and cyanate ester resins are often used as the composition of the porous impregnable adhesive layer. However, an adhesive film using these resins has a stress relaxation effect as a whole adhesive film due to the low elasticity of the core material, but warp or crack of the semiconductor chip due to a high elastic modulus of the resin cured product of the adhesive layer. In addition, warping of a semiconductor mounting substrate, cracking of a solder joint, and the like are likely to occur.

As a composition of the low elasticity adhesive layer, a system mainly containing acrylonitrile-butadiene rubber is often used. However, there are drawbacks such as a large decrease in adhesive strength after long-time treatment at a high temperature and inferior electric corrosion resistance. In particular, when a moisture resistance test is performed under severe conditions such as a PCT (pressure cooker test) process used in reliability evaluation of semiconductor-related components, deterioration is large. Further, the acrylonitrile-butadiene rubber system has a high varnish viscosity so that it is difficult to impregnate the porous film, and even if the laminating method is used, the polytetrafluoroethylene porous film is inferior in adhesion for the above-mentioned reason.

The present invention relates to a low-elastic double-sided adhesive film for bonding a semiconductor chip and an organic substrate for mounting semiconductors having significantly different coefficients of thermal expansion, and a semiconductor mounting organic substrate and a semiconductor device using the same. An object of the present invention was to improve the adhesion between the core material and the adhesive layer, and to improve the reliability such as temperature cycle resistance and reflow resistance and environmental safety.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a double-sided adhesive film for electronic parts having an adhesive layer formed on both surfaces of a core material, wherein the core material is a porous film made of a heat-resistant resin containing no halogen atoms. And a double-sided adhesive film having an adhesive layer formed on both sides thereof. Further, the present invention is a double-sided adhesive film, wherein a porous film made of a heat-resistant resin having a critical surface tension of 20 mN / m or more is used as a core material, and adhesive layers are formed on both surfaces thereof.

The moisture permeability coefficient of the porous film is 500 g / m
It is preferably at least ² / day. Further, the porosity of the porous film is preferably 5 to 95%. From the viewpoint of mass production and handling, the storage elastic modulus of the porous film is 25.
It is preferably 10 MPa or more at ℃. Further, from the viewpoint of reflow resistance, the water absorption of the heat-resistant resin is preferably 0.5 to 5% by weight. The heat-resistant resin forming these porous films is any of polyethersulfone, polyimide, polyamide, polyamideimide, polyetherimide, polyester, polysulfone, polyetheretherketone, epoxy resin, acrylic resin, and polyurethane resin. Is preferred.

The adhesive layer is made of a thermosetting resin composition and has a storage elastic modulus of 10 to 2000 MPa at 25 ° C. and a storage elastic modulus of 3 at 260 ° C. measured by a dynamic viscoelasticity measuring device of the cured product. Preferably it is ５０50 MPa. As the thermosetting resin composition, (1) 100 parts by weight of an epoxy resin and its curing agent, and (2) an epoxy equivalent of 2000
Glass transition temperature (Tg) at ~ 15000 g / mol-
100-300 parts by weight of an epoxy group-containing acrylic copolymer having a temperature of 10 ° C. or more and a weight average molecular weight of 800,000 or more,
(3) A composition containing 0.1 to 5 parts by weight of a curing accelerator is preferred. It is preferable that the surface of the double-sided adhesive film, that is, the surface of the adhesive layer has an uneven shape.

According to the present invention, there is provided an organic substrate for mounting a semiconductor, wherein the double-sided adhesive film is provided on a semiconductor chip mounting portion.

The present invention is also a semiconductor device in which a semiconductor chip and an organic substrate for mounting a semiconductor are bonded via the double-sided adhesive film.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The double-sided adhesive film of the present invention comprises a porous film made of a specific heat-resistant resin as a core material and adhesive layers formed on both sides thereof. By making the heat-resistant resin a resin containing no halogen, generation of toxic hydrogen halide during thermal decomposition can be eliminated. It is necessary that the critical surface tension of the heat-resistant resin is 20 mN / m or more. If it is less than 20 mN / m, the adhesiveness between the adhesive layer and the porous film formed from the heat-resistant resin is significantly reduced. In addition, when the composition forming the adhesive layer is used as a varnish and the varnish is applied to the surface of a porous film serving as a core material, poor coating such as "repelling" occurs. The method for producing the porous film made of the heat-resistant resin used in the present invention is not particularly limited, and a known method for producing a separation membrane such as a phase change method, a stretching method, a melting method, and a sintering method may be used. it can. Further, a nonwoven fabric or a woven fabric made of a fibrous resin can also be used as the porous film.

The moisture permeability coefficient of the porous film used in the present invention is preferably 500 g / m ² / day or more.
If the moisture permeability coefficient is less than 500 g / m ² / day, the absorbed moisture is less likely to be dehumidified during heating, which may cause a reflow crack. Conversely, by setting the moisture permeability coefficient to 500 g / m ² / day or more, a relatively large water absorption rate, for example, 3 to 5
By weight a porous film and / or adhesive layer can be used. The porosity of the porous film is 5
Preferably it is 95%. If it is less than 5%, it is difficult to obtain continuous pores, and the effect of reducing the vapor pressure during reflow is reduced. If it exceeds 95%, the mechanical strength of the porous film decreases.

In the double-sided adhesive film of the present invention, since the adhesive layer has low elasticity, the thermal stress can be alleviated. Therefore, the porous film as the core material does not need to have low elasticity.
Therefore, in consideration of workability and mass productivity in the process of manufacturing a double-sided adhesive film and the process of assembling a semiconductor device, the storage elastic modulus of the porous film is preferably 10 MPa or more at 25 ° C.

From the viewpoint of reflow resistance, the water absorption of the heat-resistant resin forming the porous film according to JIS-K-7209 is preferably 0.5 to 5% by weight. Water absorption is 0.
Less than 5% of the heat-resistant resin may have low adhesion to the adhesive layer. If the water absorption exceeds 5%, the amount of dehumidification when heated in the reflow step exceeds the above-mentioned moisture permeability, and there is a possibility of causing reflow cracks.

The heat-resistant resin used in the present invention is a heat history (eg, chip bonding, lead or wire bonding, sealing work, soldering, etc.) received in a process of assembling a semiconductor device or assembling the device into an electronic device.
A resin that can withstand at least one of physical heat resistance for maintaining a shape and chemical heat resistance for heat stability of molecular bonds. Such heat-resistant resins are commercially available as (super) engineering plastics. In particular, polyethersulfone, polyimide, polyamide, polyamideimide, polyetherimide, polyester, polysulfone, polyetheretherketone, epoxy resin, acrylic resin And a polyurethane resin.

The adhesive layer used in the present invention is preferably a thermosetting resin composition, and the cured product has a storage modulus of 10 to 2,000 at 25 ° C. measured by a dynamic viscoelasticity measuring apparatus.
It is preferably 3 MPa to 50 MPa at 260 ° C. When the storage elastic modulus exceeds 2,000 MPa at 25 ° C. and exceeds 50 MPa at 260 ° C., the effect of relieving the thermal stress caused by the difference in the coefficient of thermal expansion between the semiconductor chip and the organic substrate for mounting a semiconductor becomes small. , Peeling and cracking may occur. On the other hand, if the storage elastic modulus is less than 10 MPa at 25 ° C., the handleability of the double-sided adhesive film and the accuracy of the thickness of the adhesive layer are deteriorated, and 3 MPa at 260 ° C.
If less than a, reflow cracks are likely to occur.

As such a thermosetting resin composition,
A composition containing an epoxy resin and its curing agent, an epoxy group-containing acrylic copolymer, and a curing accelerator is preferable.

The epoxy resin may be any resin as long as it hardens and exhibits an adhesive action. An epoxy resin having two or more functional groups, preferably having a molecular weight of less than 5,000, more preferably less than 3,000 can be used. Examples of the bifunctional epoxy resin include a bisphenol A type or bisphenol F type resin. The bisphenol A type or bisphenol F type liquid resin is commercially available from Yuka Shell Epoxy Co., Ltd. under the trade names of Epikote 807, Epikote 827 and Epikote 828. In addition, Dow Chemical Japan Co., Ltd. E. FIG. R. 330, D.I. E. FIG. R. 33
1, D. E. FIG. R. 361. Further, YD8125, Y
It is marketed under the trade name DF8170. As the epoxy resin, a polyfunctional epoxy resin may be added for the purpose of increasing the Tg. Examples of the polyfunctional epoxy resin include a phenol novolak epoxy resin and a cresol novolak epoxy resin. Phenol novolak type epoxy resin is available from Nippon Kayaku Co., Ltd.
It is marketed under the trade name 01. Cresol novolak type epoxy resin is available from Sumitomo Chemical Co., Ltd.
It is commercially available under the trade names SCN-190 and ESCN-195. In addition, EOC from Nippon Kayaku Co., Ltd.
It is commercially available under the trade names N1012, EOCN1025, and EOCN1027. Further, YDCN701, YDCN702, YDCN
703 and YDCN704.

As the curing agent, those commonly used as curing agents for epoxy resins can be used, and two or more amines, polyamides, acid anhydrides, polysulfides, boron trifluoride and phenolic hydroxyl groups per molecule are used. And bisphenol A, bisphenol F, bisphenol S, and the like. In particular, it is preferable to use a phenol resin such as a phenol novolak resin, a bisphenol novolak resin, or a cresol novolak resin because of excellent electric corrosion resistance during moisture absorption. Such preferred curing agents are available from Dainippon Ink and Chemicals, Inc., phenolite LF2882, phenolite LF2822,
Phenolite TD-2090, Phenolite TD-21
49, phenolite VH4150, phenolite VH4
It is marketed under the trade name of 170. The compounding amount is preferably a logical equivalent ratio according to the epoxy equivalent of the epoxy resin, but is not limited thereto.

It is preferable to use a curing accelerator together with the curing agent, and it is preferable to use various imidazoles as the curing accelerator. Examples of imidazole include 2-methylimidazole, 2-ethyl-4-methylimidazole,
Examples thereof include 1-cyanoethyl-2-phenylimidazole and 1-cyanoethyl-2-phenylimidazolium trimellitate. Imidazoles were obtained from Shikoku Chemicals Corporation, 2E4MZ, 2PZ-CN, 2PZ-CN.
It is marketed under the trade name S. The blending amount needs to be adjusted to control the curing speed and the B-stage state, but is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the epoxy resin and its curing agent.

The epoxy group-containing acrylic copolymer has an epoxy equivalent of 2000 to 15000 g / mol and a Tg of-
A copolymer having a temperature of 10 ° C. or more and a weight average molecular weight of 800,000 or more is preferable. In a copolymer containing a carboxylic acid group or a hydroxyl group, a crosslinking reaction when the adhesive composition is formed is apt to proceed, and problems such as a decrease in the fluidity of the adhesive layer and a decrease in the adhesive force are likely to occur. . The epoxy equivalent is preferably in the range of 2000 to 15000 g / mol.
If it is less than 000 g / mol, the copolymer tends to gel, and if it exceeds 15000 g / mol, the adhesive strength is reduced.
The method for introducing an epoxy group is not particularly limited. For example, a method of copolymerizing a monomer having an epoxy group such as glycidyl (meth) acrylate, a method of copolymerizing a monomer having a hydroxyl group and then adding epichlorohydrin And a method of copolymerizing a monomer having a hydroxyl group and then adding glycidol using diisocyanate. Ethyl (meth) acrylate, butyl (meth) acrylate, acrylonitrile or a mixture thereof can be used for the remainder of the copolymer, but the mixing ratio can be determined in consideration of the Tg of the copolymer. Known methods such as pearl polymerization and solution polymerization can be used as a polymerization method for obtaining a copolymer from these monomers. If the Tg of the epoxy group-containing acrylic copolymer is lower than −10 ° C., the tackiness of the adhesive layer in the B-stage state may increase, and the handleability may deteriorate. Further, the weight average molecular weight is preferably 800,000 or more, and a good composition can be obtained in terms of the strength, flexibility, tackiness and the like of the adhesive layer. Such an epoxy group-containing acrylic copolymer is HTR-860P-
3 is commercially available from Teikoku Chemical Industry Co., Ltd. The addition amount of the epoxy group-containing acrylic copolymer is
In consideration of the storage elastic modulus of the adhesive layer, the fluidity at the time of adhesion, and the adhesiveness, 100 to 300 parts by weight is preferable for 100 parts by weight of the epoxy resin and its curing agent.

An inorganic filler can be added to the adhesive layer for the purpose of improving the handleability of the adhesive layer, improving the thermal conductivity, adjusting the melt viscosity, imparting thixotropic properties, and the like. As inorganic fillers, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina powder, aluminum nitride powder, aluminum borate whisker, boron nitride powder, crystalline Silica and amorphous silica. Alumina, aluminum nitride,
Boron nitride, crystalline silica, amorphous silica and the like are preferred. For the purpose of adjusting melt viscosity and imparting thixotropic properties, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, crystalline silica, Crystalline silica and the like are preferred.

In order to improve the interfacial bonding between different kinds of materials, a coupling agent can be blended, and a silane coupling agent is particularly preferable. As the silane coupling agent, γ-glycidoxypropyltrimethoxysilane, γ
-Mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane and the like. γ-glycidoxypropyltrimethoxysilane is NUCA-18
7. γ-mercaptopropyltrimethoxysilane is NU
CA-189, γ-aminopropyltriethoxysilane is NUC A-1100, γ-ureidopropyltriethoxysilane is NUC A-1160, N-β-aminoethyl-γ-aminopropyltrimethoxysilane is N
All are commercially available from Nippon Unicar Ltd. under the trade name UC A-1120.

Further, an ion scavenger can be blended for the purpose of adsorbing ionic impurities and improving insulation reliability during moisture absorption. Examples of the ion scavenger include compounds known as copper damage inhibitors for preventing copper from being ionized and dissolved, such as triazine thiol compounds and bisphenol-based reducing agents. As the bisphenol-based reducing agent, 2,2′-methylene-bis (4-methyl-6-third
-Butylphenol), 4,4'-thio-bis (3-methyl-6-tert-butylphenol) and the like.
Examples of the inorganic ion adsorbent include a zirconium compound, an antimony bismuth compound, and a magnesium aluminum compound. A copper damage inhibitor containing a triazine thiol compound as a component is commercially available from Sankyo Pharmaceutical Co., Ltd. under the trade name Disnet DB. A copper damage inhibitor containing a bisphenol-based reducing agent as a component is commercially available from Yoshitomi Pharmaceutical Co., Ltd. under the trade name Yoshinox BB. Various inorganic ion adsorbents are commercially available from Toa Gosei Chemical Industry Co., Ltd. under the trade name IXE.

The method for forming an adhesive layer on both sides of a porous film as a core material is not particularly limited. For example, it can be formed by a known method such as lamination, coating, and dipping. However, for the purpose of the present invention, it is necessary to form the adhesive composition so as not to fill all the pores of the porous film. Preferred methods are lamination and coating, and it is possible to precisely control the thickness of the double-sided adhesive film. In particular, the laminate is excellent in mass productivity because only the adhesive layer can be formed in advance. At this time, the thicknesses of the porous film and the adhesive layer are not particularly limited, but the total thickness of the double-sided adhesive film including these is 10%.
~ 500 µm is preferred. If it is 10 μm or less, the effect of relaxing the thermal stress is reduced, and there is a possibility that peeling or cracking may occur. If the thickness exceeds 500 μm, lead or wire bonding becomes difficult, and the thickness of the semiconductor device increases. From these, it is more preferably 50 to 250 μm.

When the adhesive layer is formed by laminating the adhesive layer on both sides of the porous film, the components of the adhesive composition are dissolved or dispersed in a solvent in advance to form a varnish, which is coated on a carrier film and heated. It is obtained by removing the solvent. As the carrier film, a plastic film such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a release-treated polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, and a polyimide film can be used. The carrier film may be peeled off before lamination to the core material,
It can also be laminated on a core material together with a carrier film and peeled off at the time of use. As an example of the carrier film, a polyimide film is commercially available from Dupont Toray under the trade name Kapton and from Kanegafuchi Chemical Co., Ltd. under the trade name Apical. Polyethylene terephthalate film is commercially available under the trade name Lumirror from Toray Industries, Inc. and under the trade name Purex from Teijin Limited.

Solvents for varnishing include relatively low boiling methyl ethyl ketone, acetone, methyl isobutyl ketone,
It is preferable to use 2-ethoxyethanol, toluene, butyl cellosolve, methanol, ethanol, 2-methoxyethanol and the like. Further, a high boiling point solvent may be added for the purpose of improving the coating properties. Examples of the high boiling point solvent include dimethylacetamide, dimethylformamide, methylpyrrolidone, cyclohexanone and the like. The production of the varnish can be carried out by a mill, a three-roll mill, a bead mill or the like, or a combination thereof, in consideration of the dispersion of the inorganic filler.
By mixing the filler and the low molecular weight material in advance and then blending the high molecular weight material, the time required for mixing can also be reduced. After the varnish is formed, it is preferable to remove bubbles in the varnish by vacuum degassing. When an adhesive layer is formed on both surfaces of the porous film by coating, the varnish can be used as it is.

It is preferable that the surface of the double-sided adhesive film, that is, the surface of the adhesive layer has an uneven shape. If the surface is uneven, air bubbles (voids) due to entrainment of air can be reduced when affixed to a semiconductor chip or a semiconductor mounting organic substrate. The method of forming such an uneven shape on the surface of the adhesive layer is not particularly limited.For example, by forming the adhesive layer on a film having an uneven shape as the carrier film, the adhesive layer having the unevenness as a replica thereof is formed. Obtainable.

The organic substrate for mounting a semiconductor chip having the above-mentioned double-sided adhesive film on the semiconductor chip mounting portion of the present invention includes an FR-4 substrate in which glass cloth is impregnated with an epoxy resin, a bismaleimide A BT substrate impregnated with a resin, a polyimide film substrate using a polyimide film as a base material, or the like can be used. The shape of the wiring may be any of single-sided wiring, double-sided wiring, and multi-layered wiring, and if necessary, a through-hole or a non-through-hole electrically connected may be provided. When the wiring appears on the outer surface of the semiconductor device, a protective resin layer may be provided. As a method of attaching the double-sided adhesive film to the semiconductor mounting organic substrate, a method of cutting the double-sided adhesive film into a predetermined shape and thermocompression bonding to a desired position on the semiconductor mounting organic substrate is generally used. There is no restriction.

The semiconductor device of the present invention has a semiconductor chip mounted on an organic substrate for mounting a semiconductor via the above-mentioned double-sided adhesive film. The method of mounting the semiconductor chip may be either face-down or face-up. As a method of mounting a semiconductor chip on an organic substrate for mounting a semiconductor, a double-sided adhesive film is cut into a predetermined shape, and is thermally bonded to a desired position on the organic substrate for mounting a semiconductor, and is permanently bonded or temporarily bonded. Is generally applied, but the method is not limited to this. The double-sided adhesive film may be bonded to the semiconductor chip first, and then bonded to the semiconductor mounting organic substrate. When a thermosetting resin composition is used for the adhesive layer, post-curing treatment may be performed after bonding the semiconductor chip and the organic substrate for mounting semiconductors.

[0035]

The present invention will be specifically described below with reference to examples.

Example 1 45 parts by weight of a bisphenol A type epoxy resin (Epicoat 828, trade name of Yuka Shell Epoxy Co., Ltd.) as an epoxy resin, a cresol novolak type epoxy resin (ESCN195, trade name of Sumitomo Chemical Co., Ltd.) ) 15 parts by weight, 40 parts by weight of a phenol novolak resin (Plyofen LF2882, trade name, manufactured by Dainippon Ink and Chemicals, Inc.) as a curing agent for an epoxy resin, and HTR-860P-3 (Eikoku) as an epoxy-containing acrylic copolymer Chemical Industry Co., Ltd., epoxy equivalent: 3500 g / mol, Tg: -5
° C, weight average molecular weight: 900,000) 150 parts by weight, 0.5 part by weight of 1-cyanoethyl-2-phenylimidazole (Curesol 2PZ-CN, trade name of Shikoku Chemicals Co., Ltd.) as a curing accelerator, γ-glycid Methyl ethyl ketone was added to 0.7 parts by weight of xypropyltrimethoxysilane (NUC A-187, trade name, manufactured by Nippon Unicar Co., Ltd.), followed by stirring and dissolution to obtain an adhesive varnish (resin solid content: 25% by weight). The adhesive varnish was applied on a release-treated polyethylene terephthalate film having a thickness of 75 μm, and dried by heating at 140 ° C. for 5 minutes to form a coating film having a thickness of 50 μm, thereby producing an adhesive film. The storage elastic modulus of the cured product of the adhesive film (heated at 170 ° C. for 60 minutes) was measured by a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology).
(Sample size: length 20mm, width 4m)
m, film thickness 50 μm, heating rate: 5 ° C./min, tensile mode, measurement frequency 10 Hz, automatic static load).
360 MPa at 260C and 4 MPa at 260C. This adhesive film is used as an adhesive layer and has a thickness of 50 as a core material.
Both sides of a μm porous polyether sulfone film (manufactured by Toyo Roshi Kaisha, Ltd.) were thermally laminated at 80 ° C. and 0.3 MPa to obtain a double-sided adhesive film.

Example 2 Double-sided adhesion in the same manner as in Example 1 except that a polyurethane resin varnish synthesized from a polyol and a diisocyanate was used as a core material and formed into a porous film having a thickness of 50 μm by a phase inversion method. A film was obtained.

Example 3 A double-sided adhesive film was obtained in the same manner as in Example 1 except that aramid paper (Nomex T410, trade name of DuPont Teijin Advanced Paper Co., Ltd.) having a thickness of 50 μm was used as a core material. .

Example 4 The procedure was carried out except that a polyetheramide resin varnish (Hymar HL1200, trade name of Hitachi Chemical Co., Ltd.) formed into a 50 μm thick porous film by a phase inversion method was used as the core material. A double-sided adhesive film was obtained in the same manner as in Example 1.

(Comparative Example 1) 100 μm thick core material
A double-sided adhesive film was obtained in the same manner as in Example 1 except that the polyimide film (UPILEX S, trade name of Ube Industries, Ltd.) was used.

(Comparative Example 2) Thickness 100 μm as core material
A double-sided adhesive film was obtained in the same manner as in Example 1, except that the polytetrafluoroethylene porous film (Poreflon WP-100, trade name, manufactured by Sumitomo Electric Industries, Ltd.) was used.

Comparative Example 3 100 parts by weight of bisphenol A type epoxy resin (Epicoat 828, trade name of Yuka Shell Epoxy Co., Ltd.), 3 parts by weight of dicyandiamide,
To 0.5 parts by weight of a curing accelerator (Epicure P-200, trade name of Yuka Shell Epoxy Co., Ltd.) is added methyl ethyl ketone / N, N-dimethylformamide (3/1 weight ratio).
In addition, the mixture was stirred and dissolved to form an adhesive varnish (resin solid content: 60% by weight). The adhesive varnish was heated and dried at 140 ° C. for 5 minutes to obtain a resin powder. The resin varnish was pressed into a plate at 170 ° C. for 1 hour, and the storage elastic modulus was measured using a dynamic viscoelasticity measuring apparatus (DVE, manufactured by Rheology Co., Ltd.). -V4) (sample size: length 20 mm, width 4 mm, film thickness 1 mm,
As a result of a temperature rising rate of 5 ° C./min, a measurement frequency of 10 Hz, a tension mode, and an automatic static load), 2500 MPa at 25 ° C.
It was 25 MPa at 260 ° C. This adhesive varnish was coated on both sides of the porous film used in Example 1 and dried to form an adhesive layer having a thickness of 25 μm, thereby obtaining a double-sided adhesive film.

A method for assembling a semiconductor device using the obtained double-sided adhesive film will be described with reference to FIG. 1, but the present invention is not limited to this. The double-sided adhesive film (1) comprises an adhesive layer (11) and a core material (12).
First, a double-sided adhesive film (1) cut into a predetermined size was thermocompression-bonded to the wiring side of the polyimide film substrate (3) on which the wiring (4) was formed at 140 ° C., 0.5 MPa, and 5 seconds. Next, the semiconductor chip (2) was thermocompression-bonded to the opposite side of the double-sided adhesive film from the substrate under the conditions of 170 ° C., 0.5 MPa, and 5 seconds. This was heated at 170 ° C. for 1 hour to cure the adhesive layer of the double-sided adhesive film.
1A, a pad of a semiconductor chip is connected to a wiring on a substrate by a bonding wire (51), and in FIG. 1B, an inner lead (52) of the substrate is bonded to a pad of the semiconductor chip to obtain a semiconductor device. Was. This semiconductor device is generally mounted on a substrate via solder balls (6).

Using the semiconductor device obtained in FIG. 1A, adhesion, temperature cycle resistance, and reflow resistance were examined. The adhesion was measured by measuring the 90-degree peel strength when the semiconductor chip was fixed and the polyimide film substrate was pulled.
The temperature cycling resistance is as follows.
A process in which the sample was left for 0 minutes and then left in an atmosphere at 125 ° C. for 30 minutes was defined as one cycle. Reflow resistance is 1 at 85 ° C and 85% RH.
The semiconductor device that had been absorbed for 68 hours was passed through an IR reflow furnace at 240 ° C. for 20 seconds and observed for peeling and cracking. X. The results are shown in Table 1.

[0045]

[Table 1] Item Example Example Example Example Example Comparative example Comparative example Comparative example Comparative example 1 2 3 4 1 2 3 Core material * 1 PES PU PA PEA PI PTFE PES Halogen No presence / absence / absence / absence / absence Critical surface tension (mN / m ) 41 45 36 43 23 18 41 Porosity (%) 60 50 35 50 0 80 60 Moisture permeability (g / m ² / day) 4000 5000 3000 5000-8000 4000 360 360 360 360 360 360 2500 Elasticity of adhesive layer Rate (MPa) (25 ° C) Adhesive force (kN / m) 1.5 1.8 1.5
1.8 1.3 0.2 1.8 Temperature cycle resistance ○ ○ ○ ○ ○ ×
× Reflow resistance ○ ○ ○ ○ × ○ ○ * 1 PES: polyether sulfone, PU: polyurethane, PA: wholly aromatic polyamide, PEA: polyetheramide, PI: polyimide, PTFE: polytetrafluoroethylene

As is clear from Table 1, all of Examples 1 to 4 had good adhesion between the core material and the adhesive layer, and were excellent in temperature cycle resistance and reflow resistance. On the other hand, in Comparative Example 1 using a non-porous core material, adhesion and temperature cycle resistance were good, but failure occurred in reflow resistance. In Comparative Example 2, since the core material was porous but polytetrafluoroethylene having a low critical surface tension was used, the adhesion between the adhesive layer and the core material was poor, and a failure occurred in the temperature cycle resistance. This was due to the interface peeling between the adhesive layer and the core material. In Comparative Example 3, since the storage elastic modulus of the adhesive layer was high, failure occurred in the temperature cycle resistance. This was a crack in the adhesive layer and an interface peeling between the adhesive layer and the semiconductor chip.

[0047]

As described above, a semiconductor device in which a semiconductor chip and an organic substrate for mounting a semiconductor are bonded by using the double-sided adhesive film of the present invention, the core material (porous film) of the double-sided adhesive film and the adhesive layer are formed. The adhesiveness is good, and the thermal stress generated due to the difference in the thermal expansion coefficient between the semiconductor chip and the organic substrate is reduced by the double-sided adhesive film, particularly the adhesive layer, so that the thermal cycle resistance is excellent. Further, since the core material is porous, the core material is excellent in reflow resistance because the vapor pressure is reduced and the stress is reduced. Further, since the core material does not contain halogen, there is no danger of generating toxic hydrogen halide. Therefore, a semiconductor device excellent in reliability and environmental safety can be obtained by using the double-sided adhesive film of the present invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a semiconductor device using a double-sided adhesive film according to the present invention, in which (a) is a semiconductor device in which a semiconductor chip and wiring on a substrate are connected by bonding wires;
(B) shows a semiconductor device in which an inner lead of a substrate is bonded on a pad of a semiconductor chip.

[Explanation of symbols]

 1. 1. Double-sided adhesive film Semiconductor chip 3. 3. Polyimide substrate Wiring 6. Solder ball 11. Adhesive layer 12. Core material 51. Bonding wire 52. Inner lead

Continued on the front page (72) Inventor Takeo Toyama 48 Wadai, Tsukuba, Ibaraki Pref. Hitachi Chemical Industry Co., Ltd. Implementation Center (72) Inventor Akira Kageyama 4-9-25 Shibaura, Minato-ku, Tokyo Within Hitachi Chemical Co., Ltd. F term (reference) 4J004 AA12 AA13 AA17 AB05 CA06 CC07 EA05 FA05 FA08 5F047 AA17 BA21 BA34 BA51 BB03

Claims (12)

[Claims] 1. A double-sided adhesive film for electronic parts having an adhesive layer formed on both surfaces of a core material, wherein the core material is a porous film made of a heat-resistant resin containing no halogen atom. Adhesive film. 2. A double-sided adhesive film for electronic parts having an adhesive layer formed on both sides of a core material, wherein the core material is a porous film made of a heat-resistant resin having a critical surface tension of 20 mN / m or more. And double-sided adhesive film. 3. The porous film having a moisture permeability coefficient of 500 g /
The double-sided adhesive film according to claim 1, wherein the double-sided adhesive film is at least m ² / day. 4. The double-sided adhesive film according to claim 1, wherein the porosity of the porous film is 5 to 95%. 5. The double-sided adhesive film according to claim 1, wherein the storage elastic modulus of the porous film at 25 ° C. is 10 MPa or more. 6. The heat-resistant resin has a water absorption of 0.5 to 5% by weight.
The double-sided adhesive film according to any one of claims 1 to 5, wherein 7. The heat-resistant resin is polyether sulfone,
The double-sided adhesive film according to any one of claims 1 to 6, which is any one of polyimide, polyamide, polyamideimide, polyetherimide, polyester, polysulfone, polyetheretherketone, epoxy resin, acrylic resin, and polyurethane resin. 8. The adhesive layer is composed of a thermosetting resin composition, and the cured product is measured by a dynamic viscoelasticity measuring device.
The double-sided adhesive film according to any one of claims 1 to 7, wherein the storage elastic modulus at 10C is 10 to 2000 MPa and the storage elastic modulus at 260C is 3 to 50 MPa. 9. The thermosetting resin composition comprises (1) 100 parts by weight of an epoxy resin and a curing agent thereof, (2) an epoxy equivalent of 2,000 to 15,000 g / mol, and a glass transition temperature of-
10. An epoxy group-containing acrylic copolymer having a temperature of 10 ° C. or more and a weight average molecular weight of 800,000 or more, 100 to 300 parts by weight, and (3) 0.1 to 5 parts by weight of a curing accelerator.
The double-sided adhesive film according to 1. 10. The double-sided adhesive film according to claim 1, wherein the surface of the double-sided adhesive film has an uneven shape. 11. An organic substrate for mounting a semiconductor, comprising the double-sided adhesive film according to claim 1 in a semiconductor chip mounting portion. 12. A semiconductor device in which a semiconductor chip and an organic substrate for mounting a semiconductor are bonded via the double-sided adhesive film according to claim 1.