JPH05339555A - Adhesive composition - Google Patents

Abstract

PURPOSE:To obtain an adhesive compsn. excellent in stress relaxation characteristics. etc., without detriment to the excellent heat resistance inherent in a polyimide by compounding an epoxy resin with a silicone-modified polyimide powder having low elasticity and water absorption. properties. CONSTITUTION:An adhesive compsn. contains, as the essential components, an epoxy resin, a curative, and a silicone-modified polyimide powder having a particle size of 30mum or lower in a wt. ratio of the powder to the sum of the resin, the curative, and the powder of 0.1-0.9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition having excellent stress relaxation characteristics and low water absorption.

[0002]

2. Description of the Related Art Adhesives used in the field of electronics are becoming more and more demanding in terms of required properties year by year.
Particularly for die mounting of semiconductor devices, the characteristics of the adhesive have led to the improvement of the total package reliability. Among them, stress relaxation property is the most important item. Generally, an epoxy resin, a curing agent, and a paste composition composed of an inorganic filler are widely used as an adhesive for die mounting, but the stress relaxation property thereof is still insufficient, especially for a large element. Further improvements were needed to address it. Further, since the epoxy resin adhesive has a high water absorption rate, there is a problem that a package crack occurs due to the adhesive in a test such as solder dipping after temperature / humidity treatment of the package, and there is room for improvement also in this point. ..

[0003]

Therefore, the present inventors have found that
As a result of intensive studies to solve the above problems, it was found that the stress relaxation property is improved by adding silicone-modified polyimide fine particles as a stress relaxation component to the epoxy resin composition, and the present invention has been completed. is there.

[0004]

That is, the present invention comprises an epoxy resin [A], a curing agent [B], and a powdery silicone-modified polyimide [C] having a particle diameter of 30 μm or less as essential components, and [A], [ The weight ratio of B] and [C] is [C] / ([A]
+ [B] + [C]) = 0.1 to 0.9, and further, an epoxy resin [A], a curing agent [B], a powdery silicone-modified polyimide [C] having a particle diameter of 30 μm or less, and an inorganic filler. [C] / [C] in weight ratio
([A] + [B] + [C]) = 0.1 to 0.9, and [D] is a weight ratio of [D] / ([A] + [B] + [C] +
[D]) = 0.1 to 0.9.

As the epoxy resin used in the present invention, known epoxy resins can be used, but in the case of electronics-related applications, the content of hydrolyzable halogen groups is 500 ppm.
The following is preferable. Furthermore, in order to obtain a paste composition, it is preferably liquid at room temperature. Examples thereof include bisphenol A diglycidyl, phenol novolac glycidyl ether, bisphenol AD diglycidyl, diglycidyl oxybenzoate, and hydrogenated compounds thereof. If necessary, a reactive diluent such as monoepoxide or alicyclic epoxide, a solvent such as butyl cellosolve acetate, or a solid epoxy resin may be added to the above epoxy resin.

As the curing agent used in the present invention, polyhydric phenols, aromatic polybasic acids, amine compounds and the like are used. These curing agents may be used in combination of two or more if necessary. Next, the silicone-modified polyimide resin used in the present invention is synthesized by condensation dehydration of aromatic acid dianhydride and diamine containing diamine having a siloxane bond.

As the aromatic dianhydride, examples of the acid dianhydride component constituting the polyimide resin used in the present invention include pyromellitic dianhydride, 3,3 ',
4,4'-benzophenone tetracarboxylic acid dianhydride,
2,2 ', 3,3'-benzophenone tetracarboxylic dianhydride, 2,3,3', 4'-benzophenone tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride Anhydrous, naphthalene-1,2,5,6
-Tetracarboxylic dianhydride, naphthalene-1,2,
4,5-tetracarboxylic dianhydride, naphthalene-1,
4,5,8-Tetracarboxylic acid dianhydride, naphthalene-
1,2,6,7-tetracarboxylic dianhydride, 4,8-
Dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride,
4,8-Dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,5 8
-Tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,
2,3,6,7-tetrachloronaphthalene-1,4
5,8-Tetracarboxylic acid dianhydride, 1,4,5,8-
Tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyltetracarboxylic dianhydride, 2,2', 3,3'-diphenyltetracarboxylic Acid dianhydride, 2,3,3 ', 4'-diphenyltetracarboxylic acid dianhydride, 3,3 ", 4
4 ″ -p-terphenyltetracarboxylic dianhydride,
2,2 ", 3,3" -p-terphenyltetracarboxylic dianhydride, 2,3,3 ", 4" -p-terphenyltetracarboxylic dianhydride, 2,2-bis (2,2 3-dicarboxyphenyl) -propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (3 , 4-Dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl)
Methane dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane Dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, perylene-2,3,8,9-tetracarboxylic dianhydride,
Perylene-3,4,9,10-tetracarboxylic dianhydride, perylene-4,5,10,11-tetracarboxylic dianhydride, perylene-5,6,11,12-tetracarboxylic dianhydride , Phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,
6,7-Tetracarboxylic acid dianhydride, phenanthrene-
1,2,9,10-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, Examples thereof include, but are not limited to, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride and thiophene-2,3,4,5-tetracarboxylic acid dianhydride.

Specific examples of the diamine used in the present invention are 1,3-bis (3-aminophenoxy) benzene and 1,3-bis (4-aminophenoxy).
Benzene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,
4-diaminomesitylene, 4,4'-methylenedi-o-
Toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline,
2,4-toluenediamine, m-phenylene-diamine, p-phenylene-diamine, 4,4'-diamino-
Diphenylpropane, 3,3'-diamino-diphenylpropane, 4,4'-diamino-diphenylethane,
3,3'-diamino-diphenylethane, 4,4'-diamino-diphenylmethane, 3,3'-diamino-diphenylmethane, 4,4 ', diamino-diphenyl sulfide, 3,3'-diamino-diphenyl sulfide,
4,4'-diamino-diphenyl sulfone, 3,3'-
Diamino-diphenyl sulfone, 4,4'-diamino-
Diphenyl ether, 3,3'-diamino-diphenyl ether, benzidine, 3,3'-diamino-biphenyl, 3,3'-dimethyl-4,4'-diamino-biphenyl, 3,3'-dimethoxy-benzidine, 4,4 ″ −
Diamino-p-terphenyl, 3,3 "-diamino-p
-Terphenyl, bis (p-amino-cyclohexyl)
Methane, bis (p-β-amino-t-butylphenyl)
Ether, bis (p-β-methyl-δ-aminopentyl) benzene, p-bis (2-methyl-4-amino-pentyl) benzene, p-bis (1,1-dimethyl-5-)
Amino-pentyl) benzene, 1,5-diamino-naphthalene, 2,6-diamino-naphthalene, 2,4-bis (β-amino-t-butyl) toluene, 2,4-diamino-toluene, m-xylene- 2,5-diamine, p-
Xylene-2,5-diamine, m-xylylene-diamine, p-xylylene-diamine, 2,6-diamino-pyridine, 2,5-diamino-pyridine, 2,5-diamino-1,3,4-oxadi Azole, 1,4-diamino-cyclohexane, piperazine, methylene-diamine,
Ethylene-diamine, propylene-diamine, 2,2-
Dimethyl-propylene-diamine, tetramethylene-diamine, pentamethylene-diamine, hexamethylene-
Diamine, 2,5-dimethyl-hexamethylene-diamine, 3-methoxy-hexamethylene-diamine, heptamethylene-diamine, 2,5-dimethyl-heptamethylene-diamine, 3-methyl-heptamethylene-diamine, 4,4 -Dimethyl-heptamethylene-diamine, octamethylene-diamine, nonamethylene-diamine, 5
-Methyl-nonamethylene-diamine, 2,5 dimethyl-
Nonamethylene-diamine, decamethylene-diamine,
1,10-diamino-1,10-dimethyl-decane,
2,11-diamino-dodecane, 1,12-diamino-
Octadecane, 2,12-diamino-octadecane,
2,17-diamino-icosane and the like can be mentioned,
It is not limited to these.

Next, as an example of the diamine having a siloxane bond, there is diaminopolysiloxane of the following formula (1).

[0010]

[Chemical 1]

[0011] _{(R 1, R 2:.} 2 divalent aliphatic group of 1 to 5 carbon atoms, or may even go a mutually same an aromatic group having 6 or more carbon atoms R ₃ , R ₄ : a monovalent aliphatic group having 1 to 5 carbon atoms or an aromatic group, which may be the same or different from each other, and n is an integer of 1 to 100).

As a method of synthesizing the silicone polyimide, a known method is applied. As an example, while diamine is dissolved in a polar solvent under a nitrogen stream, acid dianhydride is gradually added, polyamic acid is synthesized by reacting for a predetermined time, and then a solvent that is azeotropic with water is added and heated. Perform dehydration imidization. Further, the product is gradually dropped into water or methanol to precipitate the polymer, which is filtered and dried to purify the polymer. The silicone-modified polyimide thus obtained preferably has an imidization ratio of 60% or more. This is because when the imidization ratio is low, when added to the adhesive, voids are generated during curing. The obtained polymer is pulverized into a fine powder using a mixer or the like, and if necessary passed through a sieve,
The powder is 30 μm or less.

1) The presence of particles having a particle size of more than 30 μm is not preferable because it causes variations in thickness when the adhesive is applied to an adherend. The powder of this silicone-modified polyimide [C] is added to a composition comprising an epoxy resin [A] and a curing agent [B] to produce a paste composition. 2) It is preferable that the powder of silicone-modified polyimide is one that is dissolved in the epoxy resin when the adhesive is cured and the degree of dispersion is improved. This is because if the powder remains as it is, for example, when an electrically conductive filler is added, its electrical characteristics are impaired. Therefore, the weight ratio of siloxane units in all polymers is preferably 25% or less. It is also preferable that the end of the polymer is amine or dicarboxylic acid to allow reactivity with the epoxy resin, since the solubility of the silicone-modified polyimide in the epoxy resin of the final cured product is improved.

The addition amount of the silicone-modified polyimide is [C] / ([A] + [B] + [C]) = 0.1 by weight ratio.
It should be in the range of 0.9. If it is less than 0.1, improvement in stress relaxation of the epoxy resin and reduction in water absorption cannot be expected, and if it exceeds 0.9, the adhesive strength, especially the adhesive strength at the time of heating is deteriorated. Further, the viscosity is too high and the workability is deteriorated. In addition, it is also possible to add an inorganic filler to these adhesive compositions to impart thermal conductivity, electrical conductivity, mechanical strength and the like. The addition amount is a weight ratio [D] is [D] / ([A] + [B] + [C] + [D]) = 0.1
It is necessary to be ~ 0.9. If it is less than 0.1, the characteristics of the inorganic filler cannot be fully utilized, and if it exceeds 0.9, the adhesive strength of the adhesive is reduced. Examples of the inorganic filler used in the present invention include Au, Ag, Cu, Al and N.
i, metal powder such as Zn, SiO ₂ , Al ₂ O ₃ , ZnO,
Metal oxides such as TiO ₂ and BeO, AlN, BN, Si ₃
Examples thereof include nitrides such as N ₄ and carbides such as SiC, carbon, and diamond, but are not limited to these.

Production Example of Silicone-Modified Polyimide Production Example 1 1,3-Bis (3-aminophenoxy) benzene (hereinafter referred to as "1,3-bis (3-aminophenoxy) benzene" was placed in a four-necked flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet tube. APB) 1462 g (0.05
mol) and 42.09 g (0.05 mol) of silicone diamine represented by the following formula (2) (hereinafter referred to as G ₉ ) were charged and dissolved in 300 g of N-methyl-2-pyrrolidone to prepare 2,2 ′,
32.22 g (0.1 mol) of 3,3′-benzophenone tetracarboxylic acid dianhydride (hereinafter referred to as BTDA) was gradually added in powder form over 15 minutes, and then, under a nitrogen stream, 20
Stirring was continued for 5 hours at 0 ° C to carry out the reaction. Next, 25 g of toluene was added to this system, a Dean Starch reflux cooling tube was attached instead of the dry nitrogen introduction tube, and the mixture was heated in an oil bath to remove water generated by imidization from the system by azeotropic distillation with toluene. Heating was continued, imidization was promoted at 160 to 170 ° C., and the reaction was terminated 5 hours after the generation of water stopped. This polyimide varnish was added dropwise to 30 liters of methanol with stirring for 1 hour to precipitate the resin, and the solid component was collected by filtration and dried at 80 ° C. for 24 hours. The imidation ratio of the obtained polyimide was confirmed to be 100% imidized by analysis by IR spectrum.

[0016]

[Chemical 2]

This silicone-modified polyimide was powdered with a mixer while being cooled with dry ice, and was passed through a sieve to produce silicone-modified polyimide particles having a maximum particle size of 30 μm or less. (This powder is designated as S1.)

Production Examples 2 and 3 Silicone-modified polyimide particles were produced in the same manner as in Example 1 with the compounding ratios shown in Table 1. Add this powder to S2, S
Set to 3.

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

【Example】

Example 1 Bisphenol A diglycidyl (hereinafter DGEBA, epoxy equivalent 190) 50 parts by weight C ₁₄ glycidyl ester of a long-chain fatty acid (hereinafter C ₁₄ ) 50 parts by weight Dicyandiamide (hereinafter DDA) 4 parts by weight Silicone modified polyimide powder (S1) 40 Parts by weight 1,8 diazabicyclo (5,4,0) undecene 7 phenol salt (hereinafter DBU-Ph) 0.5 parts by weight silver powder 560 parts by weight butyl cellosolve acetate 10 parts by weight Using the three rolls, the above components are uniformly mixed. Was kneaded to prepare a paste adhesive. This paste was applied on a copper frame, a silicone bare chip having a size of 6 × 12 mm and a thickness of 300 μm was mounted, and cured at 200 ° C. for 1 hr to evaluate chip distortion, water absorption of the cured product, elastic modulus, and adhesive strength with heat. .. The evaluation results are shown in Table 1.

Chip distortion: A paste was applied onto a copper frame, a silicone chip (size: 6 × 12 × 0.3 mm) was mounted, and the chip was cured in an oven at 200 ° C. for 1 hr. Then, the height of the top of the chip surface was measured perpendicularly from a line connecting both ends of the chip with a surface roughness meter. Water absorption rate: The paste is cast into a size of 50 mm × 50 mm × 0.1 mm, cured at 200 ° C. for 1 hr, and
The water absorption of the film after treated at 5 ° C. and 85% RH for 100 hours was calculated from the weight change rate. Elasticity: Thermal strength: 2mm x 2mm x 0.3mm silicone chip mounted on a copper frame with paste, 200 ℃, 1h
It was cured at r and was placed on a hot plate at 350 ° C. for 20 seconds, and the shear strength immediately after it was determined by a push-pull gauge.

Examples 2 to 7 Adhesives were prepared in the same manner as in Example 1 with the compounding ratios shown in Table 1, and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results
Shown in. Comparative Example 1 Silicone-modified polyimide powder was not added, and silver powder was added to 40
An adhesive was prepared in the same manner as in Example 1 except that the amount was 0 parts by weight, and the chip strain, the water absorption rate of the cured product, the elastic modulus, and the adhesive strength with heat were evaluated. The evaluation results are shown in Table 1. Comparative Examples 2 and 3 Adhesives were prepared in the same manner as in Example 1 with the compounding ratios shown in Table 1, and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results
Shown in. In Comparative Example 3, the viscosity was too high to be used for mounting.

[0022]

[Table 1]

[0023]

INDUSTRIAL APPLICABILITY According to the present invention, by adding a silicone-modified polyimide powder having low elasticity and low water absorption to an epoxy resin composition, the characteristics of polyimide are not used, heat resistance is not lowered, and stress relaxation properties are excellent. Adhesive composition.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 29, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

As the curing agent used in the present invention, polyhydric phenols, polybasic acid anhydrides, amine compounds and the like are used. These curing agents may be used in combination of two or more if necessary. Next, the silicone-modified polyimide resin used in the present invention is synthesized by condensation dehydration of aromatic acid dianhydride and diamine containing diamine having a siloxane bond.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

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

Example 1 Bisphenol A diglycidyl (hereinafter DGEBA, epoxy equivalent 190) 50 parts by weight C ₁₄ glycidyl ester of long-chain fatty acid (hereinafter C ₁₄ ) 50 parts by weight Dicyandiamide (hereinafter DDA) 4 parts by weight Silicone-modified polyimide powder (S1) 40 parts by weight 1,8 diazabicyclo (5,4,0) undecene 7 phenol salt (hereinafter DBU-Ph) 0.5 parts by weight Silver powder 560 parts by weight butyl cellosolve acetate 10 parts by weight Then, the mixture was uniformly kneaded to prepare a paste adhesive. This paste was applied on a copper frame, a silicon bare chip having a size of 6 × 12 mm and a thickness of 300 μm was mounted, and cured at 200 ° C. for 1 hr to evaluate chip strain, water absorption rate of the cured product, elastic modulus and adhesive strength under heat. .. The evaluation results are shown in Table 1.

[Procedure amendment 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0020

[Correction method] Change

[Correction content]

Chip distortion: A paste was applied on a copper frame, a silicon chip (size: 6 × 12 × 0.3 mm) was mounted, and it was cured in an oven at 200 ° C. for 1 hr.
Then, the height of the top of the chip surface was measured perpendicularly from a line connecting both ends of the chip with a surface roughness meter. Water absorption rate: The paste is cast into a size of 50 mm × 50 mm × 0.1 mm, cured at 200 ° C. for 1 hr, and
The water absorption of the film after treated at 5 ° C. and 85% RH for 100 hours was calculated from the weight change rate. Elasticity: Thermal strength: 2mm x 2mm x 0.3mm silicon chip mounted on a copper frame with paste, 200 ℃, 1hr
Was cured at 350 ° C. for 20 seconds on a hot plate, and the shear strength immediately after that was determined by a push-pull gauge.

Claims (2)

[Claims] 1. An epoxy resin [A], a curing agent [B], a powdery silicone-modified polyimide [C] having a particle diameter of 30 μm or less as essential components, and a weight ratio of [A], [B], and [C]. Is [C] / ([A] + [B] + [C]) = 0.1
Adhesive composition characterized by being -0.9. 2. An epoxy resin [A], a curing agent [B], a powdery silicone-modified polyimide [C] having a particle diameter of 30 μm or less, and an inorganic filler [D], wherein [C] is [C] / weight ratio. ([A] + [B] + [C]) = 0.1
0.9 and [D] is a weight ratio of [D] / ([A] +
[B] + [C] + [D]) = 0.1 to 0.9.