JPH02212554A - Semiconductor sealing resin composition - Google Patents

Abstract

PURPOSE:To prepare a semiconductor sealing resin compsn. excellent in the resistance to thermal shock and soldering heat and with a low water absorption and low stress property by compounding a specific polymaleimide, a specific diamine and an inorg. filler. CONSTITUTION:A polymaleimide of formula I (wherein n is 0-10) and a polyamine of formula II (wherein n is 1-10), pref. the two components having previously been reacted with each other to form a prepolymer, are compounded and an inorg. filler (e.g. fused silica) is also compounded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a polymaleimide compound having a specific structure,
A resin composition with excellent heat resistance and low water absorption that contains a polyamine compound as an essential component, and a resin composition with excellent thermal shock resistance for encapsulating electronic components such as semiconductors that require high reliability. The present invention relates to a resin composition for encapsulating semiconductors.

[Conventional technology]

Conventionally, epoxy resins have been widely put into practical use as resin compositions for encapsulating semiconductors such as ICs and LSIs, taking advantage of their economic advantages such as low raw materials and suitability for mass production.

[Problem to be solved by the invention]

On the other hand, with the recent trend toward high-density packaging of electronic components, semiconductor packages are changing to surface-mount packages.Unlike conventional insertion-type packages, the entire package is soldered at temperatures above 200°C. Due to exposure to high temperatures, sealing resins are now required to have high heat resistance. Conventionally, bismaleimide has been widely used to obtain such high heat resistance, but cured products of bismaleimide alone have the disadvantage of being brittle, and to improve this, copolymers with diamines have been used. As a result, a method of imparting towability was adopted. However, for boat fishing, bismaleimide-based cured products have a high water absorption rate, and are considered disadvantageous, especially when considering solder heat resistance, as this water expands rapidly due to high temperatures during mounting, causing the package to crack. It's here. Furthermore, with the remarkable innovations in semiconductor technology, devices have become more highly integrated and highly functional, and the size of devices has become larger.
Aluminum wiring widths tend to become thinner. Therefore, there is a need for an even lower level of stress caused by the difference in thermal expansion between the encapsulating resin and the element, and from this point of view as well, bismaleimide-based encapsulating resins need to have low stress as well as high heat resistance. It has arisen.

[Means to solve the problem]

As a result of various studies, the present inventors have found that a cured product of a polymaleimide compound having a specific structure and a polyamine exhibits a high glass transition temperature (hereinafter referred to as Tg) and a low water absorption rate, has excellent soldering heat resistance, and The present invention was achieved by discovering that excellent thermal shock resistance can be imparted by using a modified epoxy resin in which fine polymer particles are dispersed.

That is, the present invention (1) Essentially, (a) General 2N) (n is O~10) Polymaleimide compound represented by

(b) General formula (n) (3) A polyamine compound essentially represented by (a) General formula (1) (n is 1 to 10).

(C) Inorganic filler, A resin composition for semiconductor encapsulation, characterized by containing the following.

(2) A resin composition for semiconductor encapsulation, characterized in that a polymaleimide compound represented by the general formula (1) and a polyamine compound represented by the general formula (n) are prepolymerized and used.

(n is O~10) Polymaleimide compound represented by

(b) A polyamine compound represented by the general formula (It) (n is 1 to 10).

(C) an inorganic filler; (b) a modified epoxy resin in which a silicone polymer is uniformly dispersed in a graft polymer of an epoxy resin and a vinyl polymer with a particle size of 1.0p or less; Resin composition for semiconductor encapsulation.

(4) A resin composition for semiconductor encapsulation, characterized in that a polymaleimide compound represented by the general formula (1) and a polyamine compound represented by the general formula (n) are prepolymerized and used.

(5) A resin composition for semiconductor encapsulation, which is a silicone rubber obtained by reacting a silicone polymer dispersed in an epoxy resin with an addition reaction type silicone polymer, and/or a soft vinyl polymer mainly composed of a vinyl-modified silicone polymer. .

It is.

The polymaleimide compound represented by the general formula (1) in (a) used in the present invention can be easily prepared by condensing and dehydrating a polyamine compound represented by the general formula (II) and maleic anhydride using a known method. can be manufactured.

Further, it is preferable to use the above-mentioned polymaleimide alone, but if necessary, a maleimide compound other than the general formula (I) may be used in combination.

The polyamine used in the present invention is represented by the general formula (II), but other polyamines or diamines may be used in combination, if necessary.

In the present invention, it is preferable to use the polymaleimide represented by the general formula (1) and the polyamine represented by the general formula (n) as a reactant. If not used as a reactant, it is preferable because the softening point of the polymaleimide is high. However, by using only one reactant, the softening point of the polymaleimide can be lowered, resulting in good kneading properties. can be obtained. The reaction product of the polymaleimide represented by the general formula (1) and the polyamine represented by the general formula (II) can be obtained by the method shown below.

0) Polymaleimide and polyamine are pulverized and mixed in solid form, heat treated to form a prepolymer, and then pulverized to bereft or powdered. The heating conditions in this case are preferably those that partially cure the prepolymer stage, generally at a temperature of 70 to 220°C for 5 to 240 minutes, preferably 80°C.
Suitably, the heating time is 10 to 180 minutes at a temperature of ~200°C.

(2) Polymaleimide and polyamine are dissolved in an organic solvent, then discharged into a poor solvent, and the precipitated crystals are filtered and dried to form a pellet or powder, or after being dissolved in an organic solvent, heat treatment is performed. After partially curing to the prepolymer stage, it is discharged into a poor solvent, and the precipitated crystals are filtered and dried to form pellets or powder. The conditions in this case also conform to (+). Available! The solvent is limited in that it does not substantially react with both components, but it is also desirable that it is a good solvent for the re-reacted components.Usually, the reaction solvents used are methylene chloride,
Halogenated hydrocarbons such as dichloroethane and trichloroethylene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, and diisopropyl ketone, ethers such as tetrahydrofuran, dioxane, and methyl cellosolve, aromatic compounds such as benzene, toluene, and chlorobenzene, acetonitrile, N, N -Aprotic polar solvents such as dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, and 113-dimethyl-2-imidazolidinone.

The ratio of the polymaleimide compound to the polyamine compound used is usually in a molar ratio of 10:1 to 1:3 of the polymaleimide compound of general formula (1) to the polyamine compound of general formula (■).

In addition, when used together with a modified epoxy resin in which a silicone polymer is dispersed, the compounding amount of the reactant of this polymaleimide and polyamine is 10% by weight or more based on the total amount of the epoxy resin including the modified epoxy resin and the reactant. It is preferably less than % by weight.

If it is less than 10% by weight, good soldering heat resistance cannot be obtained;
If it is used in excess of % by weight, the elastic modulus will increase, making it impossible to reduce stress sufficiently.

Examples of the inorganic filler (C) used in the present invention include powders such as crystalline silica, fused silica, alumina, talc, calcium silicate, calcium carbonate, mica, clay, and titanium white, or glass fiber and carbon. Fibers may be used singly or as a mixture, but from the viewpoint of thermal expansion coefficient, thermal conductivity, etc., pulverized and/or crystalline, meltable, etc.
Alternatively, spherical silica powder is used.

The blending amount is preferably 150 to 900 parts by weight based on 100 parts by weight of the total amount of the epoxy resin containing the reaction product of polymaleimide and polyamine or the reaction product of polymaleimide and polyamine and modified epoxy resin, and less than 150 parts by weight. The coefficient of thermal expansion is large and good thermal shock resistance cannot be obtained, and if it exceeds 900 parts by weight, the fluidity of the resin decreases and moldability is poor, making it difficult to put it to practical use.

As the epoxy resin used for the (-) of the present invention, commonly used epoxy resins can be used as long as they are polyhydric epoxy resins. Novolac epoxy resin is preferred, but other molecule contains 2
Compounds with more than 10 active hydrogen atoms, such as bisphenol A, bishydroxydiphenylmethane, resorcinol,
Polyhydric phenols such as bishydroxydiphenyl ether and tetrabromobisphenol A, ethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diethylene glycol, polypropylene glycol, bisphenol-ethylene oxide adduct, trishydroxyethyl isocyanate, etc. Glycidyl-type epoxy resin obtained by reacting epichlorohydrin with polyhydric alcohols, boric acid compounds such as ethylenediamine and aniline, and polycarboxylic compounds such as adipic acid, phthalic acid and isophthalic acid with 2-methylepichlorohydrin, An epoxy resin having a tm or higher selected from aliphatic (including alicyclic) epoxy resins such as dicyclopentadiene dieboxide, butadiene dimer diepoxide, etc. can be used.

The modified epoxy resin in (1) of the present invention can be produced by the method disclosed above by the applicant.
-273222, etc.) That is, a typical method for producing a graft polymer of an epoxy resin and a vinyl polymer is to polymerize a vinyl monomer to produce the vinyl polymer in the presence of an epoxy resin.

Here, the nyl monomer used to form the nyl polymer includes alkenyl aromatics such as styrene, vinyl toluene, etc., methyl methacrylate, dodecyl methacrylate, butoxyethyl methacrylate, glycidyl methacrylate, methyl acrylate,
Acrylic esters such as butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, trimethylolpropane triacrylate, etc., acrylic compounds without ester groups such as acrylonitrile, acrylic acid, butoxymethylacrylamide, methacrylamide, etc., vinyl Representative examples include non-conjugated vinyl compounds such as acetate, vinyl laurate, vinyl persatate, vinyl chloride, vinylidene chloride, ethylene, allyl acetate, etc., and conjugated diene compounds such as butadiene, isoprene, and chloroprene.
Polymerizable vinyl compounds such as fluorine compounds of methacrylic acid and acrylic acid such as vinyl silicone, dibutyl fumarate, monomethyl maleate, diethyl itaconate, trifluoroethyl methacrylate, and tetrafluoropropyl methacrylate can also be used. In order to polymerize the vinyl monomers described above to obtain a vinyl polymer, a radical initiator such as lauroyl peroxide, benzoyl peroxide, tert-butyl perbenzoate,
Dimethyldibenzoyl peroxyhexane, tert-butyl perbivalate, di-tert-butyl peroxide, 1.1~ and tert-butyl peroxy 3,3
．． 5-trimethylcyclohexane, dimethyl ditertiary butyl peroxyhexane, kushabutyl cumyl peroxide, methyl ethyl ketone peroxide,
Peroxides such as cyclohexanone peroxide, cumene hydroperoxide, tert-butyl peroxyallyl carbonate, dioctyl peroxydicarbonate, cou-butyl peroxymaleic acid, succinic acid peroxide, tert-butyl peroxyisopropyl carbonate, and hydrogen peroxide. Typically, radical polymerization is carried out using an azo compound such as oxide, azobisisobutyronitrile, or azobisdimethylvaleronitrile.

Also, if necessary, a reducing agent may be used in combination to carry out so-called redonx polymerization (a polymerization inhibitor such as hydroquinone or a chain transfer agent such as dodecyl mercaptan may also be used).

In addition, in order to promote grafting, it is effective to introduce a chemical bond that can be grafted, such as a polymerizable double bond, into the epoxy resin. Acrylamide, methylol acrylamide, butoxymethyl acrylamide, hydroxyethyl methacrylate, glycidyl methacrylate, maleic anhydride, monoethyl itaconate, monobutyl fumarate, chloromethylstyrene, phosphoxyethyl methacrylate, chlorohydroxypropyl methacrylate, parahydroxy A typical method is to react a compound having a functional group and a polymerizable double bond, such as styrene or dimethylaminoethyl methacrylate, with an epoxy resin in advance.

In the present invention, the epoxy resin or the vinyl polymer may remain free in the graft polymer without being grafted.

The modified epoxy resin (d) can be obtained by adding an addition-reactive silicone polymer in the presence of the graft polymer of the above-mentioned epoxy resin and a vinyl polymer, or by adding a monomer for molding a flexible vinyl polymer. It can be obtained by polymerization according to the method.

That is, addition reaction type silicone rubber is a rubber produced by an addition reaction of a vinyl-modified silicone polymer having a vinyl group in the molecule and a hydrogen-modified silicone polymer having an active hydrogen in the molecule through a silylation reaction.
Vinyl-modified silicone polymer has 5i-C at the end or inside the molecule.

CI refers to a polysiloxane having at least one bond, and a hydrogen-modified silicone polymer refers to a polysiloxane having at least two 5t-n bonds at the end or inside the molecule.

Both are usually commercially available in combination, such as Toray Silicone Co., Ltd.'s 5R-182.
1. Shin-Etsu Chemical Co., Ltd.'s Kf! -1204 etc. are mentioned.

Further, the soft vinyl polymer can be obtained by polymerizing monomers forming the soft vinyl polymer by a conventional method.

The soft vinyl polymer used in the present invention must be a polymer mainly composed of vinyl-modified silicone.A polymer mainly composed of vinyl-modified silicone means a homopolymer or copolymer of vinyl-modified silicone, or a polymer mainly composed of vinyl-modified silicone. Examples of vinyl-modified silicones, which are copolymers of modified silicones and other vinyl monomers, include methacryloxypropylsiloxane, methacryloxypropylalkoxysilane, and vinylalkoxysilane. Further, as other vinyl monomers, all the seven monomers used in preparing the graft polymers mentioned above can be used. The proportion of other vinyl monomers used is such that the obtained copolymer is soft, that is, liquid or rubbery, and has an average particle size of 1.0μ or less, and the monomer Il
Although it depends on the class, it is usually 80% by weight or less of the total monomers.

In order to achieve the object of the present invention of reducing stress and improving impact resistance, the average particle diameter of the addition reaction silicone and softened vinyl polymer is 1.0μ or less, preferably 0.5μ.
Below, it is more preferably 0.01μ or more and 0.2μ or less. If the average particle diameter of addition reaction silicone and soft vinyl polymer exceeds 1.0 μ, stress reduction cannot be achieved and thermal shock resistance cannot be improved. Control of particle size of addition reaction silicone and soft vinyl polymer is a type of vinyl polymer that forms a graft polymer with an epoxy resin,
This can be controlled by selecting the amount, addition reaction type silicone, and polymer or heptamer composition forming the flexible vinyl polymer, but it can also be controlled by the amount of double bonds introduced into the epoxy resin.

It is difficult to disperse a silicone polymer into uniform particles in an epoxy resin that does not contain a graft polymer of an epoxy resin and a vinyl polymer, even if a silane coupling agent, modified silicone oil, etc. are used, for example.

The amount of the polymer or monomer used to form the addition reaction type silicone rubber and the soft vinyl polymer is 1 to 100 parts by weight per 10 parts of epoxy resin.

The composition of the present invention has the modified epoxy resin (a) as an essential component, but also contains an unmodified polyfunctional epoxy in order to adjust the addition reaction type silicone rubber and/or soft vinyl polymer to a desired amount. You may.

As the unmodified polyfunctional epoxy, all the epoxy resins used in the above (6) can be used, and both may be the same or different.

The amount of modified epoxy resin to be used can be determined based on the desired amount of addition reaction type silicone rubber and/or soft vinyl polymer and the amount of addition reaction type silicone rubber and/or soft vinyl polymer contained in the modified epoxy resin. .

In addition, the amount of silicone rubber and/or soft vinyl polymer obtained by addition reaction is required to be 0.5% by weight or more based on the total amount of epoxy resin including polymaleimide, polyamine, and modified epoxy resin, and especially 1 to 30% by weight. % is preferred; if it is less than 0.5% by weight, low stress will not be achieved.

The resin composition for semiconductor encapsulation of the present invention can be used in the above-mentioned (a), (b), (C) or (a), (g)), (C), (b).
In practical use, it is generally used for phenols such as novolanc type phenol resins and aralkyl phenol resins, and maleimide resins such as diallyl phthalate, triallyl isocyanurate, and 010'-diallyl bisphenol A. curing accelerators such as imidazoles, tertiary amines, quaternary ammonium salts, organometallic compounds, organic phosphines, organic peroxides, azo compounds, fatty acid amides, fatty acid salts, waxes, etc. It is also possible to appropriately blend a mold release agent, a bromine compound, a flame retardant such as antimony or phosphorus, a coloring agent such as carbon black, a silane coupling agent, etc. The resin composition for semiconductor encapsulation of the present invention can be easily obtained as a molding material by sufficiently premixing with a mixer or the like, kneading with a hot roll or a melt mixer such as a Nigu, and then cooling and pulverizing. I can do it.

〔Example〕

The present invention will be specifically explained with reference to examples, but the present invention is not limited to the examples. In the following, parts mean parts by weight unless otherwise specified.

Production Example-1 (Production method of prepolymer of polymaleimide and polyamine) - 100 parts by weight of polymaleimide powder (manufactured by Sankyo Toatsu Chemical Co., Ltd.) having formula (I) and n being 3.0 on average, general formula (Ii) After reacting 251i parts of polyamine powder (manufactured by Sankyo Toatsu Chemical Co., Ltd.) with an average n of 3.0 for 10 minutes with a hot roll at 150°C, it was cooled and further pulverized to obtain a prepolymer (with a softening point of 120°C). Hereinafter referred to as a-1) was obtained.

Production Example 2 (Production method for prepolymer of polymaleimide and polyamine) 100 MM parts of polymaleimide powder having the general formula (1) with an average of 3.0, and 100 MM parts of a polymaleimide powder having the general formula (Il) with an average of 3.0. 35 tf parts of certain polyamine powder, 20 parts of methyl cellosolve
Take 0 parts by weight in a reflux-proof flask, and add 1 part by weight in a nitrogen atmosphere.
The 0 reaction solution, which was kept at 24°C and reacted for 5 hours, was added dropwise to 100 parts by weight of ethanol, and the resulting suspension was filtered.
A prepolymer with a softening point I of 25°C after being smoked at 0°C for 24 hours (
Hereinafter referred to as a-2) was obtained.

Production Example 3 (Production method of prepolymer of polymaleimide and polyamine) 100 parts by weight of a polymaleimide powder having the general formula (1) with an average n of 2.0, and the general formula (ff) with an average n of 2.0. After reacting 351i parts of polyamine powder with a hot roll at 150°C for 10 minutes, it was cooled and further crushed to a softening point of 1.
A prepolymer at 05°C was obtained.

Comparative Production Example-4 (Production method of prepolymer of polymaleimide and polyamine) 1001 parts by weight of N,N'-4,4'-diphenylmethane bismaleimide powder and 28 parts by weight of 4,4'-diaminodiphenylmethane powder were mixed at 150'C. After reacting with a heated roll for 20 minutes, it is cooled and further crushed to a softening point of 115"
A prepolymer C (hereinafter referred to as a-4) was obtained.

Production Example-5 (Production of modified epoxy resin) Orthocresol novolak epoxy resin (epoxy equivalent: 200) 1
After reacting 00 parts of toluene, 10 parts of toluene, and 1.2 parts of methacrylic acid at 120 to 125 °C for 2 hours in the presence of a tertiary amine, 10 parts of methacryloxypropyl silicone oligomer (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.4 parts of azobisisovaleronitrile and 50 parts of toluene are reacted at 80°C for 4 hours. Furthermore, 27.5 parts of vinyl-modified polysiloxane and 27.5 parts of hydrogen-modified polysiloxane (both manufactured by Shin-Etsu Chemical Co., Ltd., E-1204) were added as addition reaction type silicone polymers, and the mixture was vigorously stirred.
Allowed time to react.

Thereafter, the solvent was removed under reduced pressure at 130'C to obtain a modified epoxy resin (hereinafter referred to as b-1) in which silicone rubber with a particle size of 0.2 to 0.5μ was dispersed (epoxy equivalent: 33
7) was obtained.

Production Example-6 (Production of modified epoxy resin) Orthocresol novolac epoxy resin (epoxy ff1200)
After reacting 100 parts of toluene, 10 parts of toluene, and 1.2 parts of methacrylic acid at 120 to 125°C for 2 hours in the presence of a tertiary amine, 4 parts of butyl acrylate, 0.2 parts of glycidyl methacrylate, and t-butyl per 0.05 part of oxy 2-ethylhexanoate was reacted at 100°C for 1 hour. Furthermore, 50 parts of methacryloxypropylsiloxane,
1 part of neopentyl glycol diacrylate, 1.1-
The reaction was continued for 4 hours while continuously adding 0.15 part of bis(t-butylperoxy) 3,3.5- Modified epoxy resin (hereinafter referred to as b-2) in which a soft vinyl polymer of ~0.5μ is dispersed (epoxy equivalent: 31
3) was obtained.

Examples 1 to 3 and Comparative Example 1 The formulations shown in Table 1 were melt-mixed for 3 minutes using a 100-130'C heated roll, then cooled and crushed to obtain a molding resin composition.

Using this composition, transfer molding (185°C1
80 kg/d for 5 minutes) to form test scissors for measuring physical properties, heated at 150°C for 2 hours, and then at 200°C for 2 hours for 25 minutes.
Each test was performed after post-curing for 2 hours at 0°C.

The test results are shown in Table 2.

Example 4.5 and Comparative Example 2.3 The formulations shown in Table 3 were heated in a heated roll at 90-120°C.
After melt-mixing for a minute, a resin composition for molding was obtained by cooling, crushing, and tableting.

Using this composition, transfer molding (180°C70
kg/cd, 3 minutes) for testing with a 100-pin flat package (20 taps x 30aa x 2.5mm, 1
Qaa
Table 4 shows the results of each test.

Table 3: Mixing table: Table 1: Mixing table: Table 2: Test results: Table 4: Test results: oyv, p, s test The package was kept in a pressure Kutskar tester at 121°C and 2 atm for 24 hours, and then immediately heated to 215°C with Fluorinert. (Sumiyoshi 3N FC-70) and count the number of packages that have cranked.

(2) Aluminum slide - Displacement of the bonding butt part (100μ cutting ooμ) at the corner of the test element after performing one cycle of cooling and heating at 5”C (3D5+> ~150′C (30e)) [Effects of the invention ] As explained in the Examples and Comparative Examples, the resin composition for semiconductor encapsulation according to the present invention has high heat resistance, low water absorption, low stress, and exhibits excellent thermal shock resistance and soldering heat resistance. Therefore, when this resin composition is used to encapsulate highly integrated semiconductors or small and thin semiconductors such as flat packages, excellent performance can be obtained, making it an extremely useful invention industrially. .

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (5)

[Claims] (1) Essentially, (a) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (n is 0 to 10) Polymaleimide compound represented by (2) A polyamine compound represented by the general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (n is 1 to 10). (C) An inorganic filler. A resin composition for encapsulating a semiconductor, comprising: (C) an inorganic filler. (2) A claim characterized in that the polymaleimide compound represented by the general formula (I) in claim (1) and the polyamine compound represented by the general formula (II) are prepolymerized and used. The resin composition for semiconductor encapsulation according to item (1). (3) A polymaleimide compound essentially represented by (a) General formula (I) ▲Mathematical formula, chemical formula, table, etc.▼(I) (n is 0 to 10). (b) General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) A polyamine compound represented by (n is 1 to 10). (c) an inorganic filler; and (d) a modified epoxy resin in which a silicone polymer is uniformly dispersed in a graft polymer of an epoxy resin and a vinyl polymer with a particle size of 1.0 μ or less. Resin composition for semiconductor encapsulation. (4) A claim characterized in that the polymaleimide compound represented by the general formula (I) and the polyamine compound represented by the general formula (II) in claim (3) are prepolymerized and used. The resin composition for semiconductor encapsulation according to item (3). (5) The silicone polymer dispersed in the graft polymer of an epoxy resin and a vinyl polymer according to claim (3) is a silicone rubber obtained by reacting an addition reaction type silicone polymer and/or a vinyl-modified silicone polymer. Claim (3) which is a soft vinyl polymer mainly composed of
) The resin composition for semiconductor encapsulation described in .