JPH03100014A - Semiconductor-sealing epoxy resin composition - Google Patents

Abstract

PURPOSE:To prepare a semiconductor-sealing epoxy resin compsn. excellent in the thermal shock resistance, soldering crack resistance, and moldability by compounding a specific organopolysiloxane-modified polyfunctional epoxy resin. CONSTITUTION:A mixture of organopolysiloxanes of formulas I and II [wherein R is an org. group; R' is R or H; (n) is 30-500; and (l) and (m) are such that (l+m)/(m) is 5-50 and (l+m) is 15-500] in a wt. ratio of the organopolysiloxane of formula I to that of formula II of 0.1-100 is subjected to the addition reaction with an alkenylated polyfunctional epoxy resin (e.g. an allylated cresol novolak epoxy resin) to give an organopolysiloxane-modified polyfunctional epoxy resin. The resulting resin is compounded with a polyfunctional epoxy resin (e.g. a cresol novolak epoxy resin), a phenol novolak curing agent, a curing accelerator (e.g. triphenylphosphine), and an inorg. filler (e.g. fused silica).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an epoxy resin composition used as a semiconductor encapsulation material.

[Conventional technology]

Epoxy resin compositions containing polyfunctional epoxy compounds, phenol novolac curing agents, curing accelerators, and inorganic fillers as main components are recognized to have excellent performance, and have been used as semiconductor encapsulation materials, which have been growing rapidly in recent years. It is widely used as

However, with the increasing integration and size of semiconductors and changes in the mounting method of semiconductors on substrates, there is a strong demand for performance such as low stress and solder crank resistance, which is difficult to meet with conventional resin compositions. This is one of the causes of defects such as solder cracks and cranks caused by thermal shock in semiconductors and devices using them.

Until now, as a method to solve this problem, it has been proposed to add a block copolymer consisting of an alkenyl group-containing aromatic polymer and one type of organopolysiloxane to a curable epoxy resin (Japanese Patent Application Laid-Open No. 58-1991). However, since it is difficult to control the domain size in this block copolymer, the thermal shock resistance and solder crack resistance in a heat cycle test are insufficient.

There has been a strong desire to improve moldability, which is typified by an increase in flakiness and poor imprintability.

In order to solve these problems, a combination of organopolysiloxane and a copolymer of aromatic hydrocarbon and organopolysiloxane (Japanese Patent Application Laid-open No. 61-271319) has been proposed, but this Poor moldability occurs due to seepage of the subsequent organopolysiloxane.

Furthermore, it has been proposed to blend a copolymer of a combination of a short-chain organopolysiloxane and a long-chain organopolysiloxane with an alkenyl group-containing epoxy tree nu (Japanese Patent Laid-Open No. 63-238123). , even this one,
It has been found that poor moldability occurs due to seepage of low molecular weight components based on short chain length organopolysiloxanes.

[The invention tries to solve 1! IQ) By using an addition reaction product of a mixture of two specific organopolysiloxanes and an alkenyl group-containing polyfunctional epoxy resin, the present invention has excellent thermal shock resistance and solder crack resistance, without deteriorating mechanical properties. The object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that has excellent moldability.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a composition comprising a polyfunctional epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as main components. A compound of the formula (1)/a compound of the formula (■) = 0°1-1
By blending an organopolysiloxane-modified polyfunctional epoxy resin obtained by an addition reaction between a mixture at a weight ratio of 0.00 and an alkenyl group-containing polyfunctional epoxy resin, it has effects on thermal shock resistance and solder crack resistance. The present invention also relates to an epoxy resin composition for semiconductor encapsulation that has excellent moldability.

[Effect]

Examples of the polyfunctional epoxy resin constituting the present invention include Talesol novolac epoxy resin, phenol epoxy resin, J]115J group epoxy resin, bisphenol A novolac epoxy resin, bromide bisphenol A novolac epoxy resin, Although there are various types of epoxy resins, their use is not necessarily limited to the use of only one type, and two or more types may be mixed and used. Among functional epoxy resins, the epoxy equivalent is 150 to 2.
50, a softening point of 60 to 130° C. and from which ionic impurities such as Na'' and 01'' have been removed as much as possible are preferred.

Next, examples of the phenol novolak curing agent constituting the present invention include phenol novolak, cresol novolak, xylenol novolak, bisphenol A
Examples include novolak, resorcinol novolac resin, etc., but the use thereof is not necessarily limited to the use of only one type, and two or more types may be used in combination. Among these phenol novolac curing agents, OH equivalent is 80 to 150 and softening point is 60.
It is preferable to remove ionic impurities such as Na'' and C1- as much as possible at ~120°C.

Furthermore, as a curing accelerator for the purpose of promoting the reaction between the above-mentioned polyfunctional epoxy resin and phenol novolak resin,
Imidazole or its derivatives, tertiary amine derivatives, phosphine derivatives, cycloamidine derivatives, etc. are used.

Examples of the inorganic filler include crystalline silica, fused silica, alumina, calcium carbonate, talc, mica, and glass fiber, which may be used alone or in combination of two or more.

Furthermore, the both end-reactive type organopolysiloxane represented by formula (1) and the side chain-reactive type organopolysiloxane represented by formula (n) are used in combination, especially hydrodiene dimethylpolysiloxane, hydrodiene methylphenyl polysiloxane. , hydrogen methyl phenethyl polysiloxane is preferred. Specifically, the both-end reactive organopolysiloxane has the following formula (III
) to (V) are side chain-reactive organopolysiloxanes, such as compounds of the following formulas (VI) to (X[).

Here, the degree of polymerization of the both-end reactive organopolysiloxane of the above formula (1) is from 30 to 500, preferably from 50 to 20.
0, and the degree of polymerization of the side chain-reactive organopolysiloxane of formula (n) is 15 to 500, preferably 30 to 2.
00 range Te, (l+m)7m is 5-50, preferably 5.5-35 Ii! It is necessary that the If these ranges are exceeded, the glass transition temperature decreases due to the refinement of the seabird structure, the Paris increases, or the bending strength decreases due to phase separation due to weakening of the bond between the formed domains and the matrix. Various problems such as a decrease in Percoll hardness, a decrease in stampability, and rJJg in synthesis occur, making it impossible to achieve the object of the present invention.

Furthermore, in the present invention, it is essential to combine the both end-reactive organopolysiloxane of the above formula (1) and the side chain-reactive organopolysiloxane of the above formula (n),
The weight ratio of the both end-reactive type organopolysiloxane and the side chain-reactive type organopolysiloxane needs to be in the range of 0.1 to 100, preferably 0.5 to 20.
If it is less than 0.1, the glass transition point will decrease due to the refinement of the seabird structure, and the impact resistance or solder crack resistance will not be good, and if it is more than 100, the bond between the formed domain and the matrix will weaken. Various problems arise, such as a decrease in bending strength due to phase separation, a decrease in Percoll hardness, a decrease in stampability, and problems in synthesis.

In addition, various additives such as natural waxes, synthetic waxes, etc. may be added to the composition of the present invention as required! Il type agents, flame retardants such as hexabromobenzene, decabrombiphenyl ether, and antimony dioxide, colorants such as carbon black and red iron oxide, silane coupling agents and other synthetic rubbers, silicone compounds, thermoplastic resins, etc. may be blended as appropriate. There is no problem. After thoroughly mixing the above-mentioned composition using a mixer or the like, the mixture is heated and melt-mixed using a kneader or roll, followed by cooling, solidification, and pulverization treatment to obtain the epoxy resin composition for semiconductor encapsulation of the present invention.

〔Example〕

(Reference Example) First, a production example of an organopolysiloxane-modified polyfunctional epoxy resin constituting the present invention will be shown.

fill! Put 100 g of cresol novolac epoxy resin (epoxy equivalent: 200, softening point: 62°C) into a 300 ml four-bottle flask equipped with a reflux condenser. A meter and a dropping funnel were attached, and a mixture of 3 g of 2-allylphenol and 0.1 g of 1,8-diazabicyclo[5,4,O]-unde-7-nin was added dropwise, and the mixture was allowed to react at 150'C for 1 hour. An allylated cresol novolane epoxy resin was obtained.

Next, in a 1 liter fourth flask, 100 g of the above allylated cresol novolane epoxy resin and 4 toluene were added.
After adding 40g of water, attaching a reflux condenser and dropping funnel, and performing azeotropic distillation for 1 hour, the temperature in the system was raised to 90°C. Then, 0.5 g of a 1% Improper Tool solution of chloroplatinic acid was added, and 20 g of a mixture of both end-reactive organopolysiloxane and side chain-reactive organopolysiloxane having the weight fractions shown in Table 1 was added dropwise. The reaction mixture was allowed to react for several hours, and then the solvent was distilled off under reduced pressure to obtain an organopolysiloxane-modified polyfunctional epoxy resin.

Table 1 (Note) The organosiloxanes used are both terminal type, that is, both terminal reactive type is side II type, that is, side chain reactive type is used in Examples [1 to 5] Based on reference examples, both terminal reactive type organopolymer 50 parts by weight of an organopolysiloxane-modified polyfunctional epoxy resin (n) mixed and reacted with siloxane and side chain-reactive organopolysiloxane at the weight fractions shown in Table 1, and a cresol novolak epoxy resin (epoxy equivalent: 200, softened) Point 6
2℃) 50 parts by weight, phenol novolac tree Jlif
(OPI equivalent: 105, softening point: 100°C) 40 parts by weight,
Brominated phenol novolac epoxy resin (bromine content 30ffl%, epoxy resistance 280, softening point 71°c)
) 10 parts by weight, 530 parts by weight of fused silica, 20 parts by weight of antimony dioxide, 3 parts by weight of silane cambling agent.

4 parts by weight of triphenylphosphine, 5 parts by weight of carbana wax
5 parts by weight 5 parts by weight of carbon black were thoroughly mixed at room temperature, further kneaded at 95 to 100°C, cooled, and then crushed to form tablets to produce the semiconductor-encapsulating crucible epoxy resin composition of the present invention.

Comparative Examples [1 to 2] Organopolysiloxane-modified polyfunctional organopolysiloxanes were mixed and reacted based on reference examples so that both end-reactive organopolysiloxanes and side chain-reactive organopolysiloxanes had the weight fractions shown in Table 1. Two types of epoxy resin compositions were manufactured using epoxy resins in the same manner as in the examples.

The epoxy resin compositions produced as Examples and Comparative Examples were evaluated for mold staining properties, resin flakes, etc. using a transfer molding machine (molding conditions: mold temperature 175°C, curing time 2 minutes), and The molded products were cured at 175° C. for 4 hours, and the stampability, heat resistance [i.e. impact resistance, solder resistance, 81 mechanical strength, etc.] of the pan cages were evaluated by various tests (a) to (g).

The evaluation results are shown in Table 2.

(a) Spiral flow value: Using a mold that complies with EMMI standards, molding temperature: 175°C
, molding pressure cuff 0 Kg/am2.

(a) Paris After molding, the length of the resin pad at the vent part was measured.

(1) Percoll Hardness Molding was carried out at a molding temperature of 175° C., a molding pressure cuff of 0 Kg/cm 2 , and a molding time of 2 minutes, and the hardness was measured at a Percoll hardness of 935 at the time of molding.

(1) Moldability The number of molding shots until mold fogging occurs is 2000 or more: 0 1000 or less: X 1
000 to 2000 was evaluated as Δ.

(e) Stampability Using the 10th shot molded product, it was evaluated whether the stamp could be peeled off using Sellotape after the stamp was stamped.

What can't be peeled off O What can be peeled off × What's in between
Expressed as Δ.

(Force) Mechanical strength (flexural modulus, bending strength) According to JIS-6911, molding temperature 175°C, molding pressure cuff 0
Kg/cm2, molded for 1152 minutes at 175℃, 4
Measurements were made on those that were cured after a period of time.

(g) Glass transition point The value was measured using a deiradometer when the temperature was raised at a rate of 5° C. per minute.

(ri) Thermal shock resistance Molding temperature 175°C1 Molding pressure cuff 0 Kg/cm2,
After molding for 2 minutes and post-curing at 175°C for 8 hours, thermal cycles of -65°C x 15 minutes and 150°C x 15 minutes were repeated, and the resin crack occurrence rate after 1000 cycles was measured.

(k) Solderability After molding at a molding temperature of 175°C, a molding pressure of 0 Kg/an2, and a molding time of 2 minutes, and post-curing at 175°C for 8 hours,
After 144 hours of treatment at 85°C and 85% steam, 260
It was immersed in a solder bath at °C for 100 seconds, and the rate of occurrence of resin crank was measured.

〔Effect of the invention〕

As explained above, the present invention provides polyfunctional epoxy compounds,
Heat resistance is achieved by using an organopolysiloxane-modified polyfunctional epoxy resin containing two types of organopolysiloxanes of the above formula (1) and the above formula (II) in addition to a phenol novolac curing agent, a curing accelerator, and an inorganic filler. An epoxy resin composition for semiconductor encapsulation was obtained that had excellent impact resistance and solder crank resistance, and also had excellent moldability without deteriorating mechanical properties.

Claims (1)

[Claims] (1) (A) Polyfunctional epoxy compound (B) Phenol novolak curing agent (C) Curing accelerator (D) Inorganic filler (E) Organopolysiloxane represented by the following formulas (I) and (II) ▲Math. , chemical formulas, tables, etc.▼...(I) ▲Mathematical formulas, chemical formulas, tables, etc.▼...(II) (However, in the formula, R is an organic group, R' is an organic group or a hydrogen atom, n is 30-500, l and m satisfy (l+m)/m of 5-50 and l+m of 15-500. Semiconductor encapsulation characterized by comprising an organopolysiloxane-modified polyfunctional epoxy resin obtained by an addition reaction between a compound mixed at a weight ratio of 0.1 to 100 and an alkenyl group-containing polyfunctional epoxy resin. Epoxy resin composition for use.