JPH03119049A - Resin composition - Google Patents

Abstract

PURPOSE:To provide a resin composition having excellent moisture resistance and moldability and generating no crack in a soldering process when used as a sealing resin for semiconductors by compounding a specific epoxy resin, a hardening agent, a filler and a specific silane coupling agent. CONSTITUTION:A resin composition comprises (A) an epoxy resin having the skeletons of the formula (R<1> to R<8> are H, 1-4C lower alkyl or halogen), (B) a hardening agent, (C) a filler and (D) a silane coupling agent comprising a vinyl silane compound having a vinyl group. The component (C) is preferably employed in an amount of 75-90wt.% based on the whole amount of the resin composition and includes fused silica comprising 40-90% of crushed fused silica having an average particle size of <=12mum and 10-60% of spherical fused silica having an average particle size of <=40mum. (E) A silicone polymer may be further added to the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resin composition used for encapsulating a semiconductor device. More specifically, when mounting resin-encapsulated semiconductor devices, soldering is a resin composition that prevents cracks from occurring in the encapsulating resin during the process, and has high reliability with particularly excellent moisture resistance and moldability. The present invention relates to a granular 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. When attaching a semiconductor device to a circuit board, conventionally solder was applied to 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 250°C or higher for soldering. has been done. Therefore, when soldering a package sealed with conventional sealing resin, cracks sometimes occur in the resin part, reducing reliability and making it 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. . Humidity resistance here refers to high temperature,
This is to prevent semiconductors from breaking down due to moisture entering through the sealing resin or the interface between the sealing resin and the lead frame when a resin-encapsulated semiconductor device is placed in a high-temperature environment. As the degree of integration increases, a higher degree of moisture resistance is 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.

Furthermore, in order to improve the moisture resistance of the sealing resin, a silane coupling agent is usually added. JP-A-62-223219 and JP-A-57-155753 have been proposed.

<No problem 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 was not practical.

Furthermore, in the method of adding a vinyl silane coupling agent or an epoxy silane coupling agent, the moisture resistance by adding these agents has not yet been sufficiently improved, and it has been difficult to use them as products.

Therefore, it is an object of the present invention 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 developed an epoxy resin that achieves the above problems and meets the above objectives by adding a silane coupling agent having a vinyl group to a biphenyl-type epoxy resin. The present invention was achieved by discovering that a resin composition 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), wherein the epoxy resin (A) has the following formula (where R1 to R8 are hydrogen atoms and 01 to C4 lower alkyl groups). or a halogen atom), containing as an essential component an epoxy resin (a) having a skeleton represented by
The present invention also provides a resin composition, wherein the silane coupling agent (D) is a silane compound containing a vinyl group.

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

The epoxy resin (^) 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 above formula (2), preferred specific examples of R1 to Rδ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a 1-
prokyl 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-epoxy-10boxy)-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-epoxy 10-boxy)-3,3'5,5'-tetraethylbiphenyl and 4,4'-bis(2,3-epoxy 10-boxy)-3,3 ', 5,5'-tetrabutylbiphenyl, and the like.

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, Talezol novolac epoxy resin, phenol novolac epoxy resin, novolac epoxy resin represented by the following formula (■), etc. Synthesized from Tsukuda bisphenol A, resorcin, etc. Examples include various novolac type epoxy resins, bisphenol A type epoxy VIJ 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 (A) 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 (^) is usually 3 to 30% by weight, preferably 5 to 25% by weight.
It 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 A), and specific examples thereof include phenol novolac resin, Talesol novolac resin, novolac resin represented by the following formula (■), etc. Hot 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 device 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 it.

In the resin composition of the present invention, the 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. .8~1
．． It is preferably in the range of 3.

In addition, in the present invention, the epoxy resin (A) and the 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 thereof include 2-methylimidazole, 2,4-dimethylimidazole, and 2-ethyl- Imidazole compounds such as 4-methylimidazole, 2-phenylimidazole, 2-7enyl-4-methylimidazole, 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 2-
(dimethylaminomethyl)phenol, 2.4.6-tris(dimethylaminomethyl)phenol, tertiary amine compounds such as 1,8-diazabicyclo(5,4,0>undecene-7), zirconium tetramethoxide, zirconium tetra Organometallic compounds such as propoxide, tetrakis(acetylacetonato)zirconium, tri(acedolacetonato)aluminum and triphenylphosphine, trimethylphosphine, triethylbosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri( Organic phosphine compounds such as (nonylphenyl)phosphine are preferred. Among them, organic bosphine compounds are preferred from the viewpoint of moisture resistance, and triphenylphosphine is particularly preferably used.

Two or more of these curing catalysts may be used in combination depending on the application, and the amount added is preferably in the range of 0.1 to 10 parts by weight per 100 parts by weight of the epoxy resin.

Examples of the filler (C) in the present invention include fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magki shea, clay, talc, calcium gayate,
Examples include titanium oxide, asbecite, and glass fiber. Among them, fused silica is preferably used because it has a large effect of lowering the linear Ill coefficient and is effective in reducing stress.

Furthermore, the proportion of filler (C) is 75 to 9Of the total!
%, and the filler (C) is crushed fused silica with an average particle size of 124 or less (C'> 90 to 40ffi) and spherical fused silica (C'') with an average particle size of 404 or less 10 to 60
It is preferable to include fused silica in an amount of % by weight from the viewpoint of soldering heat resistance.

Note that the average particle size here means the particle size (median diameter) at which the cumulative W11fX amount is 50%.

The silane coupling agent (D) in the present invention is a silane compound containing a vinyl group.

Specific examples of these silane coupling agents (D) include:
Examples include those represented by the following formulas (1), (2), and (2).

R+ CI-(=C1-t-R4-3i (OR2)
n ---・-・■3-n (R1, R2, R3 are hydrogen atoms, monovalent hydrocarbon groups having 1 to 20 carbon atoms, R4 are divalent hydrocarbon groups having 0 to 20 carbon atoms, R5 is a divalent hydrocarbon group having 1 to 20 carbon atoms, and n is 1
(each represents an integer of 3 to 3) Among them, vinyltrimer 1-4disilane and γ-methacryloxyglopyltrie 1-xysilane are preferably used from the viewpoint of moisture resistance reliability.

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 purpose.

In the present invention, it is preferable in terms of reliability to previously surface-treat the filler (C) 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. Such silicone polymer #(E) has an organopolysiloxane structure, and specific examples include those represented by the following formula.

(R+ to R5 are hydrogen, a functional group of 1'In or more 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, and vinyl groups; is a functional group having one or more groups and/or atoms selected from a 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 or (m is an integer of 1 or more, n is an integer of 0 or more.) The amount of silicone polymer (E) added is usually 0.01 to 5% by weight in terms of stress reduction and reliability. %, preferably 0.
A range of 1 to 3% by weight, particularly 0.3 to 2% by weight is preferred.

The resin composition of the present invention further contains halogen compounds such as halogenated epoxy resins, flame retardants such as phosphorus compounds, flame retardant aids such as antimony dioxide, colorants such as carbon black and iron oxide, silicone rubber, and styrene-based Block copolymers, olefin copolymers, elastomers such as modified nitrile rubber and modified polybutadiene rubber, thermoplastic VIJ JJW such as polyethylene, cutting agents such as titanate cutting agents, long chain fatty acids, long chains Metal salts of fatty acids, esters of long-chain fatty acids, amides of long-chain fatty acids, mold release agents such as paraffin fuchs, 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 known kneading method such as a Banbury mixer, kneader, roll, single-screw or twin-screw extruder, or co-kneader.

<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 at the composition ratio shown in Table 5, respectively. This was tri-blended using a mixer.Then, the mixture was heated and mixed 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
Post-curing was performed for 5 hours at 75°C for 4 minutes. After post-curing, the physical properties of each composition were measured using the following physical property measuring method.

Soldering heat resistance: 64p ln20 pieces at 85℃/85%
After humidifying at 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
%RH, bias voltage 15V1: 'USPCBT was performed and the time required for the cumulative failure rate to reach 50% was determined.

Further, using the resin composition produced by the above method, the rfP value of moldability was determined by the following method.

Measurement of mold releasability: Molding was performed using a mold releasability measurement mold by a low pressure transfer molding method under the conditions of 175'CX120 seconds, and the mold release force was measured with a bush pull gauge.

◎: 5+rf or less, O: 10kgf or less, Δ: 2
0bgf or less,
Mold at 75°C for 120 seconds and observe flow marks.

◎: 100 shots or more 70-mark None ○:
50 shots or more without flow mark Δ: 10sh
Table 5 summarizes the evaluation results of ot or more, 70-marks, none X: 5 shots or more, flow marks, none or more.

Table 2 Fused silica (C) Table Silane coupling agent Table Silicone polymer As shown in Table 5, the resin composition of the present invention (Example 1
-4) are excellent in soldering heat resistance, reliability, and flow marks. On the other hand, Comparative Example 1, which does not contain biphenyl-type epoxy resin, has extremely poor soldering heat resistance, and Comparative Example 2, which does not use the vinyl silane coupling agent of the present invention, has poor soldering heat resistance, reliability, and flyability. 70-mark also appears.

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

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

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

Patent application Daitoshi Co., Ltd.

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. ) A resin composition comprising as an essential component an epoxy resin (a) having a skeleton represented by the following formula, and wherein the silane coupling agent (D) is a vinyl silane compound containing a vinyl group. (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 resin composition according to claim (1) or (2), further comprising a silicone polymer (E) in addition to components (A) to (D).