JPH0733428B2 - Method for producing silicone-modified epoxy resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an epoxy resin used for encapsulation of electronic parts such as semiconductors, especially for semiconductor encapsulation with reduced internal stress and excellent heat shock resistance. The present invention relates to a method for producing an excellent epoxy resin.

[Conventional technology]

Epoxy resin has dielectric properties, electrical properties such as volume resistivity,
In addition, it has excellent mechanical properties such as bending strength, compressive strength, and impact strength, so it is used as an insulating material for various electrical and electronic parts, and in recent years it has become particularly useful as a sealing material for semiconductors. The mainstream of sealing has been epoxy resin sealing.

[Problems to be solved by the invention]

In order to maintain the characteristics of the semiconductor, various properties are required for the encapsulating resin, but in particular, recently due to the increase in the size of the element due to the high density of the semiconductor and the introduction of new mounting methods, The occurrence of resin cracking due to the internal stress during curing due to the internal stress during thermal shock is a serious problem.

As a method of reducing the internal stress, various methods of lowering the elastic modulus have been devised, and in particular, a method of adding a flexible resin has been studied, and a method of modifying an epoxy resin with a silicone resin as the flexible resin has been proposed. Being tried.

However, it cannot be said that it is sufficiently effective in reducing the target stress. [Means for Solving Problems] As a result of intensive studies on silicone modification of an epoxy resin, the present inventors have shown that an epoxy resin and a silicone resin are sufficiently reacted, that is, a functional group that easily reacts with an epoxy group of the epoxy resin is added. We have found that a cured product of a resin obtained by reacting a silicone resin with an epoxy resin has a reduced internal stress and is excellent in heat shock resistance, and has completed the present invention.

That is, the present invention provides the following formulas (1) to (4) (Wherein x and y represent integers and R represents alkylene having 2 or 3 carbons) and one type selected from epoxy silicones represented by the following formula (5) or (6) (In the formula, R ₁ represents a hydrogen atom or a methyl group.) A silicone compound having a phenolic hydroxyl group obtained by reacting with a phenol represented by the following formula (7) (In the formula, R ₂ represents a hydrogen atom or a methyl group, and n is an integer.) The present invention relates to a method for producing a silicone-modified epoxy resin, which is characterized by reacting with a novolac type epoxy resin.

Among the above epoxy silicones, the compound represented by the formula (1) or the formula (3) is preferably used because the terminal epoxy group is more reactive.

Further, the molecular weight of the silicon compound obtained as described above, if it is small does not exert a sufficient effect, and if it is too large, the reactivity with phenols decreases, so 1,000 to 40,000 is preferable, and more preferably 2,000 to 20,000. is there. Among the phenols used in the present invention, examples of the compound represented by the formula (5) include bisphenol A and bisphenol F.

The reaction between the epoxy silicone and the compound of the formula (5) may be carried out using a catalyst usually used for the reaction between the phenolic hydroxyl group and the epoxy group, such as amines and phosphines.
In the case of the reaction with the compound of formula (6), no catalyst may be used. However, phosphines are preferable in consideration of the stability of the reaction product during storage, and the amount of the phosphine used is about 0.1 to 1% by weight based on the epoxy silicone.

A reaction solvent is not particularly required, but when the viscosity of the epoxy silicone is high, a solvent such as xylene that does not directly participate in the reaction can be used in order to smoothly carry out the reaction.

The reaction temperature is not particularly limited, but a relatively high temperature is preferable in view of the reaction rate, and 100 to 180 ° C, particularly 120 to 150 ° C is preferable.

The compound of formula (5) or formula (6) may be used in an amount of 0.5 to 5 mol, preferably 0.7 to 3 mol, more preferably 0.8 to 1.5 mol, based on 1 mol of the epoxy group of the epoxysilicone. In the case of the compound of 6), if it remains unreacted, gelation may occur in the next reaction with the epoxy resin, so it is desirable to remove the unreacted compound of the formula (6) after the reaction.

The reaction of the modified silicone resin (silicone compound having a phenolic hydroxyl group) thus obtained with the epoxy resin may be carried out by stirring the two under heating. Preferably. It is also possible to use a solvent such as xylene that does not directly participate in the reaction.

The reaction temperature is preferably 100 to 180 ° C, particularly preferably 120 to 150 ° C, but is not particularly limited. Regarding the usage ratio of the epoxy resin and the modified silicone resin, if the modified silicone resin is small, the target stress reduction cannot be sufficiently achieved, and if it is too large, the resulting resin is hard to be uniform.
The modified silicone resin is preferably used in an amount of 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, based on parts by weight.

When the reaction product of the compound of formula (5) and epoxysilicone is used as the catalyst, the catalyst added during the reaction of the compound of formula (5) and the epoxysilicone is brought in as it is, so that it is not particularly necessary to add it.

On the other hand, when a reaction product of the compound of formula (6) and epoxy silicone is used, amines or phosphines are newly added as a catalyst, and the latter is preferable. The amount used is 0.05 with respect to 100 parts by weight of modified epoxy silicone.
Is preferably 2 to 2 parts by weight, particularly preferably 0.1 to 1 part by weight.

The epoxy resin used in the production method of the present invention is a novolac type epoxy resin represented by the above formula (7), and specifically, a phenol novolac epoxy resin (R ₂ in the formula (7) is a hydrogen atom) or It is a cresol novolac epoxy resin (R ₂ in the formula (7) is a methyl group).

A cured product obtained by curing the thus obtained silicone-modified epoxy resin with a curing agent (for example, phenol novolac) is a thermosetting resin composition for encapsulation which has a particularly low flexural modulus and low stress. Can be provided.

Examples The present invention will be described below with reference to examples.

Synthesis Example 1 Silicone oil (I) (Toray Silicone BX) in a glass container equipped with a thermometer, cooling tube, nitrogen blowing tube and stirrer.
16-855B MW4400) [corresponding to the compound of formula (3)] 10
0 g, bisphenol A 10.4 g, triphenylphosphine 0.
4 g was charged and reacted at 140 ° C. for 18 hours while blowing nitrogen to obtain 105 g (product A) as a pale yellow liquid.

Synthesis Example 2 In Synthesis Example 1, silicone oil (II) (Toray Silicone BX16-854B) was used instead of silicone oil (I).
MW4400) [light-weight liquid 150 g (Product B) was obtained by the same reaction as in Synthesis Example 1 except that 100 g of [Compound of formula 4] was used.

Synthesis Example 3 In Synthesis Example 1, 5.6 g of p-methylaminophenol was used instead of bisphenol A, and xylene was used as a solvent.
ml was added, the mixture was reacted at 140 ° C. for 2 hours and 30 minutes, cooled to room temperature, methyl isobutyl ketone 2 was added, washed with water, and the organic layer was concentrated under reduced pressure to obtain 101 g of a brown liquid (product C).

Synthesis Example 4 In Synthesis Example 1, the silicone oil (I) was replaced with silicone oil (III) (Toray Silicone SF-8411 M).
W3000) [corresponding to the compound of formula (1)] 100 g,
The reaction was performed in the same manner as in Synthesis Example 1 except that 7.6 g of bisphenol A was used to obtain 103 g of a pale brown liquid (Product D).

Example 1 1 equipped with a thermometer, cooling tube, nitrogen blowing tube and stirrer
Epoxy resin (EOCN1020, Nippon Kayaku Co., Ltd., epoxy equivalent (g / mol) 200, softening temperature 65 ° C) 50 in a glass container of 50
0 g was charged, the mixture was stirred at 140 ° C. while blowing nitrogen, 75 g of the product (A) obtained in Synthesis Example 1 was added dropwise over 30 minutes, and the mixture was further reacted at 140 ° C. for 5 hours to obtain 570 g of a pale yellow solid. (Product A1). The softening temperature (JIS K7234) of the product (A1) is 6
The epoxy equivalent (g / mol) was 230 at 2.9 ° C.

Example 2 75 g of the product (B) obtained in Synthesis Example 2 instead of the product (A)
The reaction was performed in the same manner as in Example 1 except that was used to obtain 570 g of a pale yellow solid (B1).

The softening temperature of the product (B1) is 64.4 ° C and the epoxy equivalent (g / mo
l) was 231.

Example 3 75 g of the product (C) obtained in Synthesis Example 3 instead of the product (A)
Was reacted in the same manner as in Example 1 except that and 0.4 g of triphenylphosphine was used to obtain 570 g of a light brown solid (C1).

The softening temperature of the product (C1) is 63.0 ℃ and the epoxy equivalent (g / mo
l) was 231.

Example 4 75 g of the product (D) obtained in Synthesis Example 4 instead of the product (A)
The reaction was performed in the same manner as in Example 1 except that was used to obtain 570 g of a pale yellow solid (D1).

The softening temperature of the product (C1) is 63.0 ℃ and the epoxy equivalent (g / mo
l) was 231.

Example 4 75 g of the product (D) obtained in Synthesis Example 4 instead of the product (A)
The reaction was performed in the same manner as in Example 1 except that was used to obtain 570 g of a pale yellow solid (D1).

The softening temperature of the product (D1) is 64.5 ° C and the epoxy equivalent (g / mo
l) was 230.

Reference Example The silicone-modified epoxy resins (A1) and (B1) obtained in Examples 1, 2, 3 and 4 were applied to phenol novolak (manufactured by Nippon Kayaku Co., Ltd., softening temperature 85 ° C.) in the proportions shown in Table 1. ),
(C1) and (D1) were blended, and 2-methylimidazole was used as a catalyst for heat curing at 160 ° C. for 2 hours and 180 ° C. for 8 hours.

As a comparative example, the products (A1) to (D1) obtained in Examples 1, 2, 3, and 4 were heat-cured by using the raw material epoxy resin used for modification at a ratio shown in Table 1 instead of the products. did.

The glass transition temperature, heat distortion temperature and bending elastic modulus of the above cured product were measured and the results are shown in Table 1.

From Table 1, the silicone-modified epoxy resin obtained by the production method of the present invention has a glass transition temperature and a heat distortion temperature which are not different from those of the non-modified epoxy resin shown in Comparative Examples, but the elastic modulus is It is significantly reduced, and it is understood that the low stress is excellent while maintaining the heat resistance.

In addition, a thermal shock test was conducted on a cured product in which a steel washer was embedded when the components were compounded in the proportions shown in Table 1 and cured by heating. The results are as shown in Table-2. As is clear from Table-2, the cured product of the resin composition according to the present invention has excellent thermal shock resistance.

Cured product shape φ: 50 mm Thickness: 5 mm Washer plain washer (JIS M8) Thermal shock test Soak the cured product in boiling water for 30 minutes and then soak it in ice water.

〔The invention's effect〕

The cured product of the silicone-modified epoxy resin obtained by the production method of the present invention exhibits low stress and is excellent in thermal shock, and is useful as a sealing material for electronic parts.

Continuation of the front page (56) Reference JP 62-254454 (JP, A) JP 63-301220 (JP, A) JP 62-192421 (JP, A) JP 62-260817 (JP , A) JP 62-7723 (JP, A)

Claims (1)

[Claims] 1. The following formulas (1) to (4): (Wherein x and y represent integers and R represents alkylene having 2 or 3 carbons) and one type selected from epoxy silicones represented by the following formula (5) or (6) (In the formula, R ₁ represents a hydrogen atom or a methyl group.) And a silicone compound having a phenolic hydroxyl group obtained by reacting with a phenol represented by the following formula (7) (In the formula, R ₂ represents a hydrogen atom or a methyl group, and n is an integer.) A method for producing a silicone-modified epoxy resin, which comprises reacting with a novolac type epoxy resin represented by the formula: