JPH0312417A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:To obtain the subject composition giving a cured product having high toughness and excellent crack-resistance by using a specific naphthalenediol- type epoxy resin, a phenolic novolak curing agent, a cure accelerator and an inorganic filler as main components. CONSTITUTION:The objective composition is composed mainly of (A) a naphthalenediol-type epoxy resin expressed by formula (Ar is naphthalene; R is H or methyl; n is 0-5), (B) a phenolic novolak curing agent (preferably having a softening point of 50-120 deg.C). (C) a cure accelerator (e.g. triethylamine or benzyldimethylamine) and (D) an inorganic filler (preferably silica powder). The epoxy resin of the component A can be produced by reacting a naphthalenediol with an epihalohydrin or a beta-methylepihalohydrin.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an epoxy resin composition for semiconductor encapsulation, and more specifically to a semiconductor encapsulation composition that provides a cured product with high toughness and excellent crack resistance. The present invention relates to an epoxy resin composition for stopping use.

When semiconductor devices are encapsulated with resin, cracks may occur in the encapsulation resin during heat cycle tests, etc. Furthermore, as semiconductor devices have become larger and thinner in recent years, this problem has become increasingly important. Ta.

In order to solve these problems, a method of increasing the bending strength of the sealing resin has been proposed (Nikkei Microdevice, May 1988 issue, p. 36).

Specifically, a method has been adopted in which the amount of silica, which is a filler, is increased. However, when the filling amount of silica is increased in this way, the viscosity increases, causing a problem that molding workability decreases. Therefore, there is a need to develop an epoxy resin that can provide a tough cured product without increasing the amount of silica filled.

[Problem to be solved by the invention]

Accordingly, an object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that gives molded products with excellent crack resistance.

[Means to solve the problem]

That is, the present invention provides (a) the following general formula (I) R(I) (wherein Ar is a naphthalene group, R is a hydrogen atom or a methyl group, and n is an integer of 0 to 5) This is an epoxy resin composition for semiconductor encapsulation, the main components of which are a naphthalene diol type epoxy resin represented by (b) a phenol novolac curing agent, (C) a curing accelerator, and (d) an inorganic filler.

In the present invention, the epoxy resin as component (a) is easily synthesized by reacting naphthalene diols with epihalohydrin or β-methyl epihalohydrin (hereinafter both will be simply referred to as epihalohydrin).

For example, naphthalene diols and shrimp halohydrin in an amount of 2 to 15 times the mole of hydroxyl group in the Natsuta 1 non-diol are mixed at a temperature of 50 to 150°C in the coexistence of an alkaline compound such as sodium hydroxide or potassium hydroxide. 2 to 1 mole of hydroxyl group in the naphthalene diol and the naphthalene diol.
A quaternary ammonium salt such as tetramethylammonium chloride or tetraethylammonium chloride is added to a mixture with 5 times the mole of shrimp halohydrin, and 0.001 to 0.1 times mole of quaternary ammonium salt, such as tetramethylammonium chloride or tetraethylammonium chloride, is added to the mixture with 5 times the mole of hydroxyl group in the naphthalene diol. Examples include a method of ring-closing a halohydrin ether obtained by reacting at a temperature of .degree. These reactions can be carried out using solvents such as alcohols such as ethanol and butanol, and hydrocarbon compounds such as benzene and toluene, if necessary, and are usually carried out for 1 to 10 hours.

Examples of naphthalene diols include 1,4-naphthalene diol, ■, 5-naphthalene diol, ■, 6-naphthalene diol, 1.7-naphthalene diol, 2.6-
Examples include naphthalene diol and 2,7-naphthalene diol. From the viewpoint of toughness of the cured resin product, those having hydroxyl groups at symmetrical positions, such as 1,5-naphthalenediol and 2,6-naphthalenediol, are preferable, and 2,6-naphthalenediol is particularly preferable. Also,
Examples of shrimp halohydrin include epichlorohydrin, epibromohydrin, and β-methyl epibromohydrin.

The phenol novolac curing agent used in the present invention is 1
It has two or more phenolic hydroxyl groups in its molecule, and is synthesized by condensing phenols such as phenol and cresol with formalin under an acidic catalyst. From the viewpoint of molding workability, those having a softening point of 50 to 120°C are preferred.

The curing accelerator used in the present invention is used to accelerate the reaction between the epoxy resin and the phenol novolak curing agent and to speed up the curing rate. Examples of such curing accelerators include triethylamine, benzyldimethylamine, and 2.4.6-tris(dimethylaminomethyl).
Tertiary amines such as phenol, imidazoles such as 2-methylimidazole, 2-ethyl-4methylimidazole, and 2-undecylimidazole, organic phosphines such as triphenylphosphine, and 1,8-diazabicyclo[5 , 4°0] undecene-7 and its phenol salts and formates.

A common epoxy resin may be blended into the composition of the present invention, if necessary. These epoxy resins include
For example, there are bisphenol A type epoxy resin, novolak type epoxy resin, etc.

Examples of the novolac type epoxy resin include phenol novolac type epoxy resin, cresol novolac type epoxy resin, and brominated phenol novolac type epoxy resin. The amount of these epoxy resins is as follows:
A suitable range is 0 to 200 parts by weight per 100 parts by weight of the naphthalene diol type epoxy resin.

Furthermore, in the present invention, it is necessary to incorporate an inorganic filler into the composition. As this inorganic filler,
Examples include fused silica, crystalline silica, quartz glass powder, talc, alumina powder, calcium carbonate, glass fiber, etc., and one type or a mixture of two or more types selected from the group consisting of these is used.

As these inorganic fillers, silica powder is particularly preferred, and the silica powder may be in any shape such as crushed or spherical.

The inorganic filler used in the present invention has an average particle size of 2 to 25 mm in consideration of moldability. Preferably, m.

Further, from the viewpoint of maintaining fluidity during molding, the blending ratio of this inorganic filler is preferably 85% by weight or less, and more preferably in the range of 65 to 75% by weight.

Furthermore, in the present invention, a mold release agent, a coloring agent, a coupling agent, a lubricant, a stress reducing agent, a flame retardant, etc. may be added as necessary.

〔Example〕

The present invention will be specifically described below based on Examples and Comparative Examples.

Synthesis Example 1 700 parts by weight of epichlorohydrin was added to 100 parts by weight of 1.5-naphthalene diol, and the mixture was heated at 1150C with stirring to 48% by weight.
104 parts of wtX sodium hydroxide aqueous solution was added dropwise over 3 and a half hours. The water produced during this time was removed from the system by azeotroping with epichlorohydrin, and the distilled epichlorohydrin was returned to the system.

After the dropwise addition of the 48wtX sodium hydroxide aqueous solution was completed, the reaction was further carried out at 115°C for 15 minutes.

After the reaction was completed, excess epichlorohydrin was removed by distillation, and 200 parts by weight of methyl isobutyl ketone was added.
The reaction product was dissolved and collected. Thereafter, methyl isobutyl Kent was distilled off, and 146 parts by weight of a pale yellow epoxy resin (A-1) was obtained using 1154 parts by weight of epoxy resin.

Next, 100 parts by weight of the obtained resin and 5 parts of a phenol novolac resin (OH equivalent 1O4, softening point 68°C) as a curing agent were added.
3 parts by weight were melt-mixed under heating, 2 parts by weight of triphenylphosphine as a curing accelerator was added, and the mixture was heated to 100°C.
After heating and kneading for a minute, test pieces were molded by transfer molding at 150°C.

The glass transition point, coefficient of linear expansion, and fracture toughness of this test piece were investigated. Here, the glass transition point was measured using a thermomechanical analyzer at a heating rate of 7°C/min.

Moreover, the fracture toughness is A, F, Yee.

R.A., Pearson, Journal of
Materials 5science.

21, 2462 (1986).

The results are shown in Table 1.

Synthesis Example 2 An epoxy resin was synthesized in the same manner as in Synthesis Example 1 using 1.6-naphthalenediol to obtain 166 parts by weight of an epoxy resin (A-2) having an epoxy equivalent of 149 and being viscous at room temperature.

Using the obtained resin, a test piece was prepared in the same manner as in Synthesis Example 1, and its physical properties were measured. The results are shown in Table 1.

Synthesis Example 3 Using 1.7-naphthalenediol, an epoxy resin was synthesized in the same manner as in Synthesis Example 1 to obtain 163 parts by weight of an epoxy resin (A-3) having an epoxy equivalent of 149 and being viscous at room temperature.

Using the obtained resin, a test piece was prepared in the same manner as in Synthesis Example 1, and its physical properties were measured. The results are shown in Table 1.

Synthesis Example 4 Using 2.6-naphthalene diol, a reaction was carried out in the same manner as in Synthesis Example 1 to obtain 144 parts by weight of a crystalline epoxy resin (A-4) having an epoxy equivalent of 158.

Using the obtained resin, a test piece was prepared in the same manner as in Synthesis Example 1, and its physical properties were measured. The results are shown in Table 1.

Comparative Synthesis Example 1 O-cresol novolac type epoxy resin (CA-1,
A test piece was prepared in the same manner as in Synthesis Example 1 using an epoxy equivalent of 158 and a softening point of 70°C, and its physical properties were measured. The results are shown in Table 1.

Table 1 The epoxy resins of Synthesis Examples 1 to 4 and Comparative Synthesis Example 1 and phenol novolak resin (B, curing agent) were blended in the proportions (parts by weight) shown in Table 2, and triphenylphosphine (hardening accelerator) was added to the mixture. agent) 2 parts by weight, fused silica (inorganic filler) 4
50 parts by weight, 2 parts by weight of carvana wax, and 2 parts by weight of carbon black were blended, kneaded with heated rolls, and then cooled and pulverized to obtain an epoxy resin composition.

The spiral flow of the obtained epoxy resin composition was measured by the EMMI method, and the gelation time at 175°C was determined. Furthermore, the 16-bottle DIP was sealed by L-transfer molding, and then it was heated to absorb moisture (85°C,
85XRH, 24 hours), then solder immersion (260
℃, 10 seconds), and then a crack test was conducted by determining the crack generation rate.

The results are shown in Table 2.

Examples 1-5. Comparative Example 1 (Table 2) This is extremely useful as a resin composition for semiconductor encapsulation.

Claims (2)

[Claims] (1) (a) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (However, in the formula, Ar is a naphthalene group, R is a hydrogen atom or a methyl group, and n is 0 to (integer of 5)), (b) a phenol novolac curing agent, (c) a curing accelerator, and (d) an inorganic filler as main components. Epoxy resin composition for semiconductor encapsulation. (2) The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein in the general formula (I), Ar is a 2,6-naphthylene group.