JPH03119051A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide an epoxy resin composition giving semiconductors generating no crack when soldered and having excellent moisture resistance and mold release property by compounding a specific epoxy resin, a hardening agent, a filler and a specified silane coupling agent. CONSTITUTION:An epoxy resin composition (A) an epoxy resin having the skeletons of the formula I (R<1> to R<8> are H, 1-4C lower alkyl or halogen), (B) a hardening agent, (C) a silane coupling agent containing an alkylsilane compound of formula II (R<1> is 1-20C alkyl, phenyl or halogen; R<2> and R<3> are H or 1-20C monovalent hydrocarbon) and (D) a filler. The composition may further contain (E) a silicone polymer. The component D preferably contains fused silica comprising 40-90% of crushed fused silica having an average particle size of <=12mum and spherical fused silica having an average size of <=40mum and is employed in an amount of 75-90wt.% based or whole amount of the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an epoxy resin composition used for encapsulating semiconductor devices. More specifically, when mounting resin-encapsulated semiconductor devices, soldering is an epoxy resin composition that prevents cracks from occurring in the encapsulating resin during the process. The present invention relates to a reliable epoxy resin composition.

<Conventional technology> In recent years, in the field of semiconductor integrated circuits, along with the development of technologies for higher integration and higher reliability, automation of the process of assembling semiconductor devices onto wiring boards has been promoted. Traditionally, when attaching a device to a circuit board, soldering was done for each lead bin, but recently a surface mount method has been adopted in which the entire semiconductor device is immersed in a solder bath heated to over 250°C for soldering. There is. As a result, packages sealed with conventional sealing resins have the problem that cracks sometimes occur in the resin part when soldering, reducing reliability and making the package unusable as a product.

In addition, as a method for encapsulating semiconductors, a general method is to use a composition containing an epoxy resin with a hardening agent, a filler, etc., set the semiconductor element in a mold, and encapsulate it by a transfer molding method or the like. It is being said.

The properties required of these resins for semiconductor encapsulation include soldering heat resistance, reliability, and moldability.Reliability includes moisture resistance, and moldability includes mold releasability, flow marks, etc. .

Moisture resistance here means that when a resin-sealed semiconductor device is placed in a high-temperature environment, moisture may enter through the sealing resin or the interface between the sealing resin and the lead frame, causing the semiconductor to fail. In recent years, as the degree of integration of semiconductors has improved, a higher degree of moisture resistance has been required.

In view of the above-mentioned actual situation, as a conventional method for improving the solder crack resistance of sealing resin, for example, a method using biphenyl-type epoxy resin (Japanese Patent Application Laid-Open No. 63-25141
9) have been proposed.

In addition, as a conventional method for improving the moisture resistance of sealing resin, a method of adding an alkylsilane coupling agent to ordinary epoxy resin (Japanese Patent Application Laid-Open No. 59-8715,
JP-A-59-27945 and JP-A-61-15
1234) and a method of adding epoxy silane (Japanese Patent Publication No. 6.2-17640) have been proposed.

<Problems to be Solved by the Invention> However, although the method using biphenyl-type epoxy resin improves the solder crack resistance of the sealing resin, there are problems such as a decrease in moisture resistance and mold releasability, and flow marks. It wasn't practical.

Furthermore, in the method of adding an alkylsilane coupling agent or an epoxysilane coupling agent, the moisture resistance is still not sufficiently improved by adding these agents, and it has been difficult to use them as a product.

Therefore, an object of the present invention is to solve the problems of the epoxy resin composition for semiconductor encapsulation described above, and to create an epoxy resin that has excellent reliability such as soldering heat resistance and moisture resistance, and moldability such as mold releasability and flow marks. An object of the present invention is to provide a composition that enables a resin-encapsulated semiconductor for surface mounting.

Means for Solving the Problems> The present inventors have created an epoxy resin composition that achieves the above problems and meets the above objectives by adding an alkylsilane coupling agent to a biphenyl-type epoxy resin. The present invention was achieved by discovering that the following can be obtained.

That is, the present invention uses an epoxy resin (^), a curing agent (B)
, a filler (C) and a silane coupling agent (D), the epoxy resin composition comprising:
^) is an epoxy resin (a) having a skeleton represented by the following formula ■ RI R5R8R2 (wherein R1-R8 represents a hydrogen atom, a lower alkyl group of 01 to C4, or a halogen atom) as an essential component. Contains
and the silane coupling agent (D) has the following formula: The present invention provides an epoxy resin composition characterized by containing an alkylsilane compound represented by the formula () representing a hydrogen group.

Hereinafter, the configuration of the present invention will be explained in detail.

The epoxy resin (A) in the present invention is a biphenyl-type epoxy resin ( It is important to contain a) as an essential component.

If the epoxy resin (a) is not contained, the effect of preventing cracks in the soldering process cannot be expected.

In the following formula 〇, preferred specific examples of R1-R8 include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a 1-
10 Kyl group, n-butyl group, 5ec-butyl group, ter
Examples include t-butyl group, chlorine atom and bromine atom.

Preferred specific examples of the epoxy resin (a) in the present invention include 4,4'-bis(2,3-epoxypropoxy)biphenyl, 4,4'-bis(2°3-epoxypropoxy)-3,3' , 5.5'-tetramethylbiphenyl, 4.4'-bis(2,3-epoxypropoxy)-3,3', 5.5'-tetramethyl-2
-chlorobiphenyl, 4,4'bis(2,3-epoxypropoxy)-3,3,5°5'-tetramethyl-2-
Bromobiphenyl, 4,4'-bis(2,3-epoxypropoxy)-3,3'5,5'-tetraethylbiphenyl and 4,4'-bis(2,3-epoxypropoxy)-3,3', Examples include 5,5'-tetrabutylbiphenyl.

The epoxy resin (A) in the present invention can contain, together with the above-mentioned epoxy resin (a), another epoxy resin other than the epoxy resin (a). Other epoxy resins that can be used in combination include, for example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, novolac type epoxy resin represented by the following formula 0, etc. Synthesized from hot bisphenol A, resorcinol, etc. Examples include various novolac type epoxy resins, bisphenol A type epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, and halogenated epoxy resins.

Epoxy resin (a) contained in epoxy resin (A)
There is no particular restriction on the ratio of It is usually necessary to contain it in the resin (^) in an amount of 30% by weight or more, preferably 50% by weight or more.

In the resin composition of the present invention, the blending amount of the epoxy resin (A) is usually 3 to 30% by weight, preferably 5 to 2Sffl.
The amount is %.

As the curing agent (B) in the present invention, epoxy resin (
It is not particularly limited as long as it is cured by reacting with ^), and specific examples thereof include phenol novolac resin, talesol novolac resin, novolac resin represented by the following formula 0, ...-Φ bisphenol Various novolak resins synthesized from A and resorcinol, various polyhydric phenol compounds, acid anhydrides such as maleic anhydride, phthalic anhydride, and pyromellitic anhydride, and aromatic amines such as metaphenylene diamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples include.

Among these, novolac resins such as phenol novolac and cresol novolac are preferably used for semiconductor encapsulation from the viewpoint of heat resistance, moisture resistance, and storage stability, and depending on the application, two or more types of curing agents may be used in combination. You can also do that.

In the resin composition of the present invention, the blending amount of the curing agent (B) is usually 1 to 20% by weight, preferably 2 to 15% by weight. Furthermore, from the viewpoint of mechanical properties and moisture resistance, the compounding ratio of the epoxy resin (A) and the curing agent (B) should be such that the chemical equivalent ratio of (B) to (^) is 0.5 to 1.6, especially 0. .8
It is preferably in the range of 1.3 to 1.3.

In addition, in the present invention, epoxy resin (^) and curing agent (
A curing catalyst may be used to promote the curing reaction of B). The curing catalyst is not particularly limited as long as it promotes the curing reaction, and examples include 2-methylimidazole, 2.4-dimethylimidazole, and 2-ethyl- Imidazole compounds such as 4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-he1tadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 2-
(dimethylaminomethyl)phenol, 2.4.6-tris(dimethylaminomethyl)phenol, 1.8-diazabicyclo(5,4,0)endecene-7, etc.
grade amine compounds, zirconium tetramethoxide, zirconium tetrapropoxide, tetrakis(acetylacetonato)zirconium, tri(acetylacetonato)
Examples include organometallic compounds such as aluminum, and organic phosphine compounds such as triphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri(P-methylphenyl)phosphine, and tri(nonylphenyl)phosphine. Among them, from the viewpoint of moisture resistance, organic phosphine compounds are preferred, and triphenylphosphine is particularly preferably used.

These curing catalysts may be used in combination of two or more depending on the application, and the amount added is determined depending on the epoxy resin Jfff (A).
A range of 0.1 to 10'fIL parts per 100 parts by weight is preferred.

The filler (C) in the present invention includes fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate,
Examples include titanium oxide, asbecite and glass fiber. Among them, fused silica is #! It is preferably used because it has a large effect of lowering the expansion number and is effective in reducing stress. Furthermore, the proportion of the filler (C) is 75 to 90% of the total.
% by weight, and the filler (C) has an average particle size of 12 IIm.
The following crushed fused silica (C') 90 to 40% by weight and spherical fused silica (C'') with an average particle size of 40 B+ or less 10 to
It is preferable to include 60% by weight of fused silica in terms of half-fB heat resistance.

Note that the average particle size here refers to the particle size that accounts for 50% of the cumulative weight (
median diameter).

The silane coupling agent (D) in the present invention is an alkylsilanized metal represented by the above-mentioned general ⑧. Specific examples of the silane coupling agent (D) include methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyljethoxysilane, trimethylmethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, and phenyltrimethoxysilane. , phenyltriethoxysilane, phenyldimethylethoxysilane and triphenylmethoxysilane, among which phenyltrimethoxysilane and trimethylmethoxysilane are preferably used.

The amount of these silane coupling agents (D) added is usually 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, particularly preferably 0.3 to 1 part by weight, based on 100 parts by weight of the filler. ．．
The amount is 5 parts by weight, and other silane coupling agents such as epoxysilane, mercaptosilane, and aminosilane may be used in combination depending on the application.

In the present invention, it is preferable in terms of reliability that the filler (C) is previously surface-treated with a silane coupling agent (D) and, if necessary, another silane coupling agent such as epoxysilane or mercaptosilane.

In the present invention, a silicone polymer (E) can be further added in order to reduce stress and improve reliability of the composition. The curved silicone polymer (E) has an organopolysiloxane structure, and specific examples thereof include those represented by the following formula (2).

(Rz to R5 are hydrogen, one or more functional groups selected from alkyl groups having 1 to 20 carbon atoms, phenyl groups and vinyl groups, X and Y are alkyl groups having 1 to 20 carbon atoms, phenyl groups,
A functional group having one or more groups and/or atoms selected from a vinyl group, a hydroxyl group, an amino group, an epoxy group, a carboxyl group, a mercapto group, a polyoxyalkylene group, an alkoxy group, and a fluorine atom, and Y is hydrogen. In addition, m is an integer of 1 or more, and n is an integer of 0 or more. % by weight, preferably 0.
A range of 1 to 3% by weight, especially 0.3 to 2% by weight is preferred.

The epoxy resin composition of the present invention further includes halogen compounds such as halogenated epoxy resins, flame retardants such as phosphorus compounds, flame retardant aids such as antimony trioxide, colorants such as carbon black and iron oxide, silicone rubber, Styrenic block copolymers, olefin copolymers, elastomers such as modified nitrile rubber and modified polybutadiene rubber, thermoplastic resins such as polyethylene, coupling agents such as titanate coupling agents, long chain fatty acids, long chain fatty acids Metal salts of metal salts, esters of long chain fatty acids, amides of long chain fatty acids, mold release agents such as paraffin wax, and crosslinking agents such as organic peroxides can be optionally added.

The epoxy resin composition of the present invention is preferably produced by melt-kneading using a publicly known kneading method such as a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder, and a co-kneader. Ru.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

To the formulation shown in Table 1, the fused silica shown in Table 2, the silane coupling agent shown in Table 3, and the modified silicone oil shown in Table 4 were blended in the composition ratio shown in Table 5, respectively. This was tri-blended using a mixer.Then, the mixture was heated and kneaded for 5 minutes using a mixing roll with a roll surface temperature of 90°C, and then cooled and pulverized to produce an epoxy-containing composition.

Using this composition, 1
It was molded at 75° C. for 2 minutes, and then post-cured for 5 hours. After post-curing, the physical properties of each composition were measured using the following physical property measuring method.

Soldering heat resistance: 20 64pin0FPs at 85℃/
After humidifying at 85% RH for 50 hours, the QFPs were immersed in a solder bath heated to 260° C. for 10 seconds, and the percentage of QFPs without cracks was determined.

Reliability: 120℃/85 using 16pin DIP
USPCBT was performed at %RH and bias voltage of 15V, and the time required for the cumulative failure rate to reach 50% was determined.

Furthermore, using the epoxy resin composition produced by the above method, moldability was evaluated by the following method.

Measurement of mold releasability: Molding was performed at 175° C. for 120 seconds using a mold releasability measurement mold using a low-pressure transfer molding method, and the mold release force was measured using a bush-pull gauge.

◎: 5 kgf or less 0: 10 kgf or less Δ: 201 qrf or less X: 30 krf or more Flow mark: Diameter 1 by low pressure transfer molding method
0c! A disk of I was molded at 175° C. for 120 seconds, and flow marks were observed.

◎: 100 shots or more without flow mark ○:
50 shots or more without flow mark Δ: 10sh
Table 5 summarizes the evaluation results for 5 shots or more with no flow mark: 5 shots or more with no flow mark.

Table 2 Fused silica (C> Table Silane coupling agent Table Silicone polymer As shown in Table 5, the epoxy resin composition of the present invention (
Examples 1 to 4) are excellent in soldering heat resistance, reliability, and flow marks. On the other hand, Comparative Example 1, which does not contain biphenyl-based epoxy resin, has extremely poor soldering heat resistance, and Comparative Example 2, which does not use the alkylsilane coupling agent of the present invention, has poor soldering heat resistance, reliability, and mold release properties. Moreover, flow marks also appear.

Furthermore, the epoxy resin compositions of the present invention containing 75 to 90% by weight of specific fused silica (Examples 7 to 10) have excellent reliability and further improved soldering heat resistance.

In addition, as shown in Table 5, the epoxy resin composition of the present invention (Example 11) further containing a silicone polymer
-14) have excellent soldering heat resistance and further improved reliability and mold releasability.

<Effects of the Invention> The epoxy resin composition of the present invention has excellent solder heat resistance, reliability, and moldability, and has ideal performance for semiconductor encapsulation.

Claims (3)

[Claims] (1) Epoxy resin (A), curing agent (B), filler (C
) and a silane coupling agent (D), in which the epoxy resin (A) has the following formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (However, R ^1~R^8 are hydrogen atoms, C_1~C_4
represents a lower alkyl group or a halogen atom. ) Contains as an essential component an epoxy resin (a) having a skeleton represented by (II) (R^1 represents an alkyl group having 1 to 20 carbon atoms, a phenyl group, or a halogen atom, R^2 and R^3 are hydrogen atoms,
Represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. ) A semiconductor epoxy resin composition comprising an alkylsilane compound represented by: (2) The proportion of the filler (C) is 75 to 90% by weight of the total, and the filler (C) is 40 to 90% by weight of crushed fused silica (C') with an average particle size of 12 μm or less and an average particle size 4
10 to 60% by weight of spherical fused silica (C″) of 0 μm or less
The resin composition according to claim 1, characterized in that it contains fused silica (C) consisting of fused silica (C). (3) The epoxy resin composition according to claim (1) or (2), further comprising a silicone polymer (E) in addition to components (A) to (D).