JPH1036789A - Thermosetting bonding tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a thermosetting bonding tape, having excellent operating efficiency and excellent in fast-curability, heat and moisture resistances and adhesion. SOLUTION: This thermosetting bonding tape consists essentially of a resin composition consisting essentially of a resin composition prepared by blending a solvent-soluble prepolymer, obtained by reacting a maleimide compound having >=2 maleimide groups in one molecule with an amino compound having >=2 amino groups in one molecule in an organic solvent and having the weight- average molecular weight within the range of 20,000 to 200,000 (component A) with a crosslinking agent reactive with the maleimide group in the maleimide compound of the prepolymer of the component A (component B) and at least one resin selected from the group consisting of an acrylic rubber, an ethylene- acrylic rubber and an acrylonitrile-butadiene rubber (component C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting composition having excellent adhesiveness to a metal, a laminated board and a silicon substrate as a circuit board material or a semiconductor mounting material, and also has a fast curing property and a heat resistance property, particularly for use in bonding electronic parts. The present invention relates to an adhesive tape.

[0002]

2. Description of the Related Art Adhesive tapes for electronic parts are used, for example, for fixing laminated boards, flexible circuit boards, lead frames, etc., and are used for joining metals to laminated board materials, metals to heat-resistant plastic films, and metals to metals. Is what you do.
There is a demand for smaller, lighter, more reliable and simpler mounting methods for communication, industrial, and consumer equipment, which is accompanied by an increase in the capacity of semiconductor chips and fine pitch of printed circuits and lead frames. With rapid progress, higher functionality and higher reliability are required. As an example of this, there is a flexible circuit board using a light and foldable plastic film as an insulating substrate. Various adhesive resin compositions for bonding a plastic film and a metal foil have been studied so far. For example, epoxy resin, polyacrylonitrile resin, polyacrylate ester resin, phenol resin / nitrile rubber, phenol resin / Polyvinyl acetal, phenolic resin / epoxy resin / polyvinyl acetal, phenolic resin / epoxy resin / nitrile rubber, bismaleimide / cyanate ester resin, etc. are used alone or as a mixture to develop and commercialize adhesives. . However, although epoxy resins are excellent in adhesiveness, electrical insulation, and mechanical properties, they are not sufficiently satisfactory in terms of heat resistance. Although phenolic resin has some heat resistance,
At present, it has not been possible to completely overcome the problems that residual free phenol is generated as a gas at the time of processing and that low-molecular-weight substances significantly lower the cured physical properties of the resin.
Recently, higher functionality has been required for materials, and various resin compositions have been developed. Conventionally used resins, such as phenolic resins and epoxy resins, have also been eagerly developed so as to be compatible with special applications from general-purpose materials. However, it cannot be said that all the required characteristics are satisfied. On the other hand, high-performance polymers called super-engineering plastics such as polyamide, polyimide, polyamide imide, polyether ketone, and polyphenylene sulfide have appeared and have been developed for various uses. However, it is not always the case that super engineering plastics have overcome all the required characteristics. For example, polyimide resin, which is one of super engineering plastics, has excellent heat resistance, but is insoluble or insoluble in various solvents, and therefore, it is very difficult to mold. For the purpose of improving molding processability, polyimide resins soluble in organic solvents have been developed and marketed, but high-boiling amide solvents are often used as solvents for resin varnishes, and residual solvents are often used. In some cases, the properties of the resin may be impaired. On the other hand, if the solubility in a general-purpose organic solvent is to be increased, the heat resistance is significantly impaired. Bismaleimide resins are also well known and have been put to practical use in applications where heat resistance is strict in the field of molding materials and laminate materials. However, the cured product obtained by thermally polymerizing a bismaleimide resin is extremely brittle and easily cracks, and there are still problems in practical use. Workability such as the need to press for a long time under high temperature and pressure to obtain a good cured product In addition, productivity problems have arisen. In addition, bismaleimide resin has low solubility in organic solvents compared to phenol resin and epoxy resin, and often has poor compatibility with other resins.Bismaleimide resin is combined with epoxy resin and phenol resin. When used as a material, in the case of a solid material such as a molding material, it must be sufficiently kneaded with a mixer or a roll to uniformly disperse the resins. When used as a resin varnish by dissolving in an organic solvent, even if the bismaleimide resin is dissolved in a high-boiling amide-based solvent, a very high temperature and long time process is required to evaporate the solvent. There are disadvantages. Also, the physical properties of the cured product finally obtained in this way may be significantly different from those expected. As described above, the thermosetting adhesive resin using a bismaleimide resin has a disadvantage that the heat curing requires a high temperature and a long time and the productivity is inferior. It is very difficult to satisfy the demand for a highly reliable adhesive such as contamination and high hygroscopicity.
There is a demand for the development of a more reliable adhesive with improved processability and productivity.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosetting adhesive tape which has both processability and heat resistance and has high productivity.

[0004]

Means for Solving the Problems In view of the above circumstances, the present inventors have conducted intensive studies to solve the problems. As a result, the maleimide compound and the amino compound were reacted, and were soluble in an organic solvent and had a weight average molecular weight. Up to 200,000 prepolymers have been synthesized, and it has been found that a resin composition containing this as a curing component is suitable for the above-mentioned purpose, and the present invention has been completed.
That is, the present invention provides a solvent-soluble and weight-average compound obtained by reacting a maleimide compound having two or more maleimide groups in one molecule with an amino compound having two or more amino groups in one molecule in an organic solvent. Molecular weight from 20,000 to 2
Prepolymers (component A) ranging up to 00,000
A crosslinking agent (component B) that reacts with a maleimide group in the maleimide compound or the prepolymer of component A, and at least one selected from the group consisting of acrylic rubber, ethylene-acryl rubber and acrylonitrile-butadiene rubber Is a thermosetting adhesive tape having a resin composition obtained by blending the resin (Component C) as a main component, wherein the weight ratio of each component in the resin composition is 100 parts by weight of Component A and Component B Is 0.5 to 8 parts by weight, and component C is 20 to
The thermosetting adhesive tape is 200 parts by weight.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The maleimide compound used for obtaining the resin composition component A in the present invention is represented by the following general formula (1):
Has two or more maleimide groups in one molecule.

[0006]

Embedded image (In the formula, X is a divalent or higher valent organic group, and n is an integer of 2 or more.)

For example, various bismaleimides can be used as having two maleimide groups in one molecule. Specifically, 1-methyl-2,4-bismaleimidebenzene, N, N '-M-phenylenebismaleimide, N, N'-p-phenylenebismaleimide,
N, N'-m-toluylenebismaleimide, N, N'-
4,4'-biphenylenebismaleimide, N, N'-
4,4 '-[3,3'-dimethyl-biphenylene] bismaleimide, N, N'-4,4'-[3,3'-dimethyldiphenylmethane] bismaleimide, N, N'-4,
4 '-[3,3'-diethyldiphenylmethane] bismaleimide, N, N'-4,4'-diphenylmethanebismaleimide, N, N'-4,4'-diphenylpropanebismaleimide, N, N'-4 , 4'-diphenylether bismaleimide, N, N'-3,3'-diphenylsulfonebismaleimide, N, N'-4,4'-diphenylsulfonebismaleimide, 2,2-bis [4- (4
-Maleimidophenoxy) phenyl] propane, 2,2
-Bis [3-t-butyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] decane, 1,1-bis [2-methyl-4
-(4-maleimidophenoxy) -5-t-butylphenyl] -2-methylpropane, 4,4'-cyclohexylidene-bis [1- (4-maleimidophenoxy) -2
-(1,1-dimethylethyl) benzene], 4,4'-
Methylene-bis [1- (4-maleimidophenoxy)-
2,6-bis (1,1-dimethylethyl) benzene],
4,4′-methylene-bis [1- (4-maleimidophenoxy) -2,6-di-s-butylbenzene], 4,
4′-cyclohexylidene-bis [1- (4-maleimidophenoxy) -2-cyclohexylbenzene, 4,
4'-methylenebis [1- (maleimidophenoxy)-
2-nonylbenzene], 4,4 '-(1-methylethylidene) -bis [1- (maleimidophenoxy) -2,6
-Bis (1,1-dimethylethyl) benzene], 4,
4 ′-(2-ethylhexylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4 ′-(1-methylheptylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4'-cyclohexylidene-bis [1- (maleimidophenoxy) -3-methylbenzene], 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [4- (4-maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-
Methyl-4- (4-maleimidophenoxy) phenyl]
Hexafluoropropane, 2,2-bis [3,5-dimethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3,5-dimethyl-4- (4-
Maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-ethyl-4--4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-
Ethyl-4- (4-maleimidophenoxy) phenyl]
Hexafluoropropane, bis [3-methyl- (4-maleimidophenoxy) phenyl] methane, bis [3,5
-Dimethyl- (4-maleimidophenoxy) phenyl]
Methane, bis [3-ethyl- (4-maleimidophenoxy) phenyl] methane, 3,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo- [5
2,1,0 ^2.6 ] decane, 4,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo- [5,
2,1,0 ^2.6 ] decane, 3,9-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo- [5,
2,1,0 ^2.6 ] decane, 4,9-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo- [5,
2,1,0 ^2.6 ] decane, 1,8bis [4- (4-maleimidophenoxy) phenyl] menthane, 1,8bis [3-methyl-4- (4-maleimidophenoxy) phenyl] menthane, 1,8 -Bis [3,5-dimethyl-4
-(4-maleimidophenoxy) phenyl] menthane, and these can be used alone or in combination.

As those having three or more maleimide groups in one molecule, tris (4-maleimidophenyl) methane, bis (3,4-dimaleimidophenyl) methane, poly (4-maleimidostyrene), and There is a polymaleimide obtained by maleimidating an aromatic polyamine such as an aniline resin obtained by a reaction between aniline and formaldehyde represented by the formula (2). Specifically, a polymaleimide represented by the following general formula (3) is used. Can be mentioned. These polymaleimide compounds can be used alone or in combination, and the bismaleimide compounds can be used in combination.

[0009]

Embedded image (Where k is an integer of 2 or more)

[0010]

Embedded image (Wherein, m is an integer from 1 to 5, R is a hydrogen atom or a monovalent organic group)

The amino compound used in the present invention includes, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, N-aminoethylpiperazine, 1,4-bis (aminopropyl) piperazine, trimethylhexamethylene Diamine, 4,4′-diaminodiphenylmethane,
4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, m-phenylenediamine, 2,4-toluylenediamine, 2,6-toluylenediamine, o-toluylenediamine, xylylenediamine, dimethylphenylene Diamine, 2,2-bis (4-
(4-aminophenoxy) phenyl) propane, 1,3
-Bis (3-aminophenoxy) benzene, 2,2-bis (4
-(4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4-aminophenoxy) hexafluoropropane, bis-4- (4-aminophenoxy) phenylsulfone, bis-4- (3-aminophenoxy ) Phenylsulfone, 4,4′-diaminodicyclohexylmethane, 3,
3'-Dimethyl-4,4'-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, 1,3-bis (aminomethyl) cyclohexane, polyamine, aniline resin, etc., which can be used alone or in combination Can be used.

The reaction between the maleimide compound and the amino compound is performed in an organic solvent. Examples of the solvent include benzene, toluene, xylene, tetrahydrofuran, dioxane, ethyl acetate, acetonitrile, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-
2-pyrrolidone, dimethyl sulfoxide and the like.

The prepolymer obtained by reacting a maleimide compound with an amino compound must be soluble in an organic solvent. If the composition is not soluble in a solvent, a resin composition having excellent molding processability, which is the object of the present invention, cannot be obtained. The weight average molecular weight of the prepolymer obtained by reacting the maleimide compound and the amino compound is 20,000.
00 to 200,000, and even 40,000 to 15
More preferably, it is 0.000. When the weight average molecular weight is less than 20,000, the melt viscosity becomes low and the flow of the resin cannot be controlled, and the disadvantages of the maleimide resin such as high crosslink density and hard but brittle cannot be overcome. On the other hand, when the weight average molecular weight is more than 200,000, the solubility in an organic solvent is reduced, and the prepolymer is undesirably precipitated during the reaction, and the melt viscosity becomes too high to improve the processability. is there.

In the method of thermosetting the adhesive tape, that is, the adhesive resin of the present invention, the prepolymer of component A, which is a curing component, can be cured without a catalyst, but can be more easily cured by using a crosslinking agent. Is possible,
An improvement in productivity which is the object of the present invention can be expected. Organic peroxides are preferred as crosslinking agents that react with the maleimide groups in the prepolymer. It is particularly preferable when the purpose is to improve productivity by shortening the curing time. Specifically, t-butyl cumyl peroxide, dicumyl peroxide,
α, α′-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-
Butylperoxy) hexane, 2,5-dimethyl-2,
Preferable examples include 5-di (t-butylperoxy) hexyne-3. AIBN, di-t-butyl peroxide, acetyl peroxide, etc. have low decomposition temperatures,
Poor storage stability and cured physical properties are not preferred. The amount of the crosslinking agent added is preferably 0.5 to 8 parts by weight based on 100 parts by weight of the prepolymer of the component A. More preferably, it is 0.8 to 5 parts by weight. If the amount is less than 0.5 part by weight, the curing is not completed in a short time, and the cured product becomes uneven, which is not preferable. If it is used in excess of 8 parts by weight, it may foam during curing,
Cured physical properties are reduced by the crosslinking agent remaining without being decomposed.

The resin component C used in the present invention comprises acrylic rubber, ethylene-acrylic rubber, acrylonitrile-
It is at least one resin selected from the group consisting of butadiene rubbers, and acrylonitrile-butadiene rubber is more preferred, especially when compatibility with component A is emphasized.
The amount ratio is preferably 20 to 200 parts by weight based on 100 parts by weight of the prepolymer of the component A. If the amount is less than 20 parts by weight, the toughness of the cured product is undesirably reduced. If the amount exceeds 200 parts by weight, the flow of the resin composition cannot be controlled and the workability is reduced, and the cured physical properties of the maleimide are not sufficiently exhibited. The adhesive resin of the present invention, a phenolic resin as long as the properties of the resin composition are not impaired,
An epoxy resin, a cyanate resin or the like can be used in combination. Also, addition of an inorganic filler to the adhesive resin of the present invention is not prevented.

The organic solvent for dissolving the adhesive resin is not particularly limited, but preferably has a boiling point of 120 ° C. or lower. For example, acetone as a ketone solvent,
Examples thereof include methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone.
These solvents may be used alone or in combination of two or more. Amide solvents such as N,
N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, etc. have a high boiling point and require a high temperature at the time of coating and drying.

Various additives such as a leveling agent, a leveling agent, and a defoaming agent for improving the surface smoothness can be added to the resin varnish as needed. In the present invention, in order to make a resin varnish into an adhesive tape, it is obtained by casting or coating a resin varnish, for example, using a heat-resistant film substrate as a support, and forming an adhesive resin layer on one or both surfaces in the same manner. And adhesive tape with the support, roll,
A film can be formed on a release sheet such as a metal sheet or a polyester sheet by a flow coater, a roll coater, or the like, and then heated and dried, and then peeled off to obtain an adhesive tape.

The heat-resistant film substrate used in the present invention is such that the polyimide resin film has a small coefficient of thermal expansion and is excellent in dimensional stability against temperature change, has high flexibility and is easy to handle, Is preferred in that it has excellent adhesion. In particular, a polyimide resin having a glass transition temperature of 350 ° C. or more is excellent in workability and stability in a step of drying a coating varnish. The application and drying of the resin varnish can be performed using an apparatus in which an application facility such as a flow coater or a roll coater is combined with a hot-air drying oven. After applying the resin varnish to the support, the resin varnish is guided to a hot-air drying oven and dried at a temperature and air volume sufficient to volatilize the solvent of the varnish. Although the method of using the adhesive tape of the present invention is not particularly limited, the adhesive tape may be subjected to a continuous laminating method by roll-to-roll rolling in a short time or a thermoblock which is cut into a predetermined shape and heated. A bonding method may be used. The present invention has excellent workability,
The present invention also relates to a thermosetting adhesive tape which is excellent in fast curing property, heat resistance, moisture resistance, and adhesiveness. Various fields where heat resistance, adhesiveness and mechanical strength are required, especially for electronic component bonding applications, specifically industrially as materials for bonding metals, laminates, and silicon substrates as circuit board materials and semiconductor mounting materials Extremely high utility value. Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0019]

【Example】

(Synthesis Example 1) Toluene 848.4 according to the formulation in Table 1.
g to 2,2-bis (4- (4-maleimidophenoxy)
Phenyl) propane (BMI-80, manufactured by K-I Kasei Co., Ltd.) 150 g, 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane (H
-PAM, manufactured by Shin-Etsu Silicone Co., Ltd.) (62.1 g) was added, heated to 60 ° C., and reacted for 2 hours. After completion of the reaction, the reaction solution was allowed to cool to room temperature, poured into a large amount of methanol to precipitate a resin component as Component A, and the prepolymer was washed by filtration, separated, and sufficiently dried. The molecular weight of the obtained prepolymer was analyzed using high performance liquid chromatography (GPC-209G Waters, column: G4000HXL, G3000HXL, G200).
0HXL, G1000HXL, solvent: tetrahydrofuran, flow rate: 1.0 ml / min, detector: RI). The weight average molecular weight was 89000 and the number average molecular weight was 18,000.

[0020]

[Table 1]

(Synthesis Examples 2 to 4) According to the composition shown in Table 1, a prepolymer was obtained in the same manner as in Synthesis Example 1.

Example 1 According to the composition shown in Table 2, 400 g of methyl ethyl ketone (MEK) was added to the above prepolymer 1
After adding 100 g and dissolving uniformly, acrylonitrile-
Butadiene rubber (N220SH, Nippon Synthetic Rubber Co., Ltd.)
Was dissolved in 400 g of MEK, and the mixture was stirred at room temperature for 1 hour. Then, 2 g of α, α'-bis (t-butylperoxy-m-isopropyl) benzene (PBP, manufactured by NOF Corporation) was added and stirred for 1 hour to obtain a resin composition solution. This resin solution was applied to one surface of a polyimide film (trade name: Upilex SGA, thickness: 50 μm, manufactured by Ube Industries, Ltd.) using a reverse roll coater to obtain an adhesive tape having an adhesive layer thickness of 30 μm. The drying temperature was up to 110 ° C. and the drying time was 6 minutes. This adhesive tape was pressure-bonded to a 35 μm electrolytic copper foil on a glossy metal surface not subjected to black treatment by a hot press having a heat block to prepare a test piece. The bonding condition is 120 ° C / 1
Seconds, the pressure was 4 kg / cm ² . This test piece was
The composition was cured on a hot plate at 0 ° C./90 seconds, and the 180 ° peel strength was measured by a tensile tester (tensile speed 50 mm /
min). The strength was 1.26 kgf / cm, showing excellent adhesion to copper. In the fractured surface, the adhesive layer was cohesively fractured, and no void was observed at the time of pressing or curing. The physical properties of the adhesive resin after curing were measured using a film-shaped test piece. The adhesive resin solution is applied to a stainless steel plate coated with a release agent, dried in the same manner as a copper foil test piece, and cured together with the stainless steel plate on a hot plate at 200 ° C. for 90 seconds to obtain a film-like test piece after peeling. Was. The thermal decomposition onset temperature was measured by TG / DTA (heating rate 10 ° C / min,
Under air), water absorption rate is JIS K7209 (D-24hr)
/ 23 ° C). The results are shown in Table 2.

[0023]

[Table 2]

(Examples 2 to 4) An adhesive resin solution was prepared in the same manner as in Example 1 with the composition shown in Table 2 to prepare an adhesive tape, and evaluation results were obtained.

(Comparative Examples 1 to 3) Test pieces were prepared and evaluated in the same manner as in Example 1 according to the composition shown in Table 3.

[0026]

[Table 3]

From the results shown in Table 3, when the molecular weight of the component A is low, the resin flow cannot be controlled, and voids are generated during curing. It is also found that if the amount ratio of the component C to 100 parts by weight of the component A is out of the range of 20 to 200 parts by weight, all of the resin flow, voids and adhesive strength cannot be satisfied. The above examples show that the present invention can provide a thermosetting adhesive tape excellent in adhesiveness, heat resistance, and moisture resistance that can withstand practical use even in a short curing time.

[0028]

The thermosetting adhesive tape according to the present invention relates to a thermosetting adhesive tape which has excellent workability and is excellent in quick-curing properties, heat resistance, moisture resistance and adhesiveness.
In particular, it is extremely useful industrially as a material for bonding electronic components, specifically, as a material for bonding metals, laminates, and silicon substrates as materials for circuit boards and semiconductors. Further, continuous workability can be achieved, and an improvement in productivity can be expected.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C09J 7/00 JHL C09J 7/00 JHL 109/02 JEB 109/02 JEB 133/04 JDD 133/04 JDD 179/08 JGE 179/08 JGE

Claims (5)

[Claims] (A) A solvent-soluble compound obtained by reacting a maleimide compound having two or more maleimide groups in one molecule with an amino compound having two or more amino groups in one molecule in an organic solvent. And the weight average molecular weight is 20,000
(B) a cross-linking agent which reacts with a maleimide group in the maleimide compound of the component A or in the prepolymer, (C) an acrylic rubber, an ethylene-acrylic rubber and acrylonitrile-butadiene. A thermosetting adhesive tape containing, as a main component, a resin composition containing at least one resin selected from the group consisting of rubber. 2. The resin composition comprises 0.5 to 8 parts by weight of component B and 20 to 20 parts by weight of component C based on 100 parts by weight of component A.
The thermosetting adhesive tape according to claim 1, which is a resin composition containing 0 parts by weight. 3. The thermosetting adhesive tape according to claim 1, wherein the maleimide compound as the component A is bismaleimide, and the amino compound is a diamino compound. 4. The thermosetting adhesive tape according to claim 1, wherein the crosslinking agent of the component B is an organic peroxide. 5. The thermosetting adhesive tape according to claim 1, wherein the resin of component C is acrylonitrile-butadiene rubber.