JPH08134329A - Production of epoxy resin composition - Google Patents

Abstract

PURPOSE: To obtain an epoxy resin composition capable of affording a sealing material excellent in solder crack resistance due to uniform dispersion of pulp therein by kneading an epoxy resin in a melt state so as to provide a viscosity within a specific range with the pulp. CONSTITUTION: This composition is obtained by melting (A) an epoxy resin having >=2 epoxy groups (preferably an o-cresol novolak-based epoxy resin) and kneading the component (A) having a viscosity within the range of 200-10000cP with (B) a pulp (preferably the one obtained from an aromatic polyamide resin). The blending ratio of the components (A) with (B) is preferably 0.5-5 pts.wt. based on 100 pts.wt. component (A). Furthermore, the component (B) preferably has 3-20/g specific surface area according to the BET method and 150-700ml freeness measured by the Canadian standard type method specified by JIS P-8121.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an epoxy resin composition in which pulp is uniformly dispersed. A cured product using the same relates to an epoxy resin composition which has excellent toughness and is useful for sealing electronic parts.

[0002]

2. Description of the Related Art Recently, LSIs, ICs, transistors, etc.
Transfer molding with an epoxy resin, which is economically or excellent in performance, is used for sealing a semiconductor. In general, a sealing material using a resin composition in which an glycidyl ether of o-cresol novolac is used as an epoxy resin, a phenol novolac is used as a curing agent, and an inorganic filler such as silica is mixed is the mainstream. recently,
The surface mounting of LSIs is performed, and the number of cases in which they are directly immersed in a solder bath is increasing. At that time, the sealing material is 20
Since it is exposed to a high temperature of 0 ° C. or higher, the moisture absorbed in the encapsulant vaporizes and expands, causing cracks and peeling at the interface with the die pad. Therefore,
There is a strong demand for improvement in solder crack resistance for resin encapsulants.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing an epoxy resin composition which can provide a sealing material having excellent solder crack resistance.

[0004]

Means for Solving the Problems The present inventors have found that an epoxy resin composition in which pulp is uniformly dispersed provides a resin toughened product with high toughness and is effective as a resin encapsulant excellent in solder crack resistance. As a result of discovering that there is such a problem, and as a result of diligent examination of the manufacturing method thereof, the inventors have invented a manufacturing method which is industrially excellent. In the present invention, in producing an epoxy resin composition comprising (a) an epoxy resin having two or more epoxy groups in a molecule and (b) pulp, the epoxy resin is melted and the viscosity of the epoxy resin is 200 to A method for producing an epoxy resin composition, which comprises kneading with pulp within a range of 10,000 centipoise.

The present invention will be described in detail below. As the epoxy resin of the component (a) used in the production method of the present invention, known epoxy resins can be used. Examples of these include hydroquinone, resorcin, bisphenol A, tetrabromobisphenol A, bisphenol F, tetra Methylbiphenol, 4,4'-dihydroxybenzophenone, bis (4-hydroxyphenyl)
Ether, glycidyl ether derived from dihydric phenols such as bis (4-hydroxy-3,5-dimethylphenyl) thioether and trihydric or higher phenols such as phloroglysin and pyrogallol, phenol, cresol, xylenol, butylphenol, Methylbutylphenol, octylphenol, etc. (including each isomer)
Of formaldehyde, acetaldehyde, glyoxal, acrolein, benzaldehyde, hydroxybenzaldehyde and other aldehydes or cyclohexanone, acetophenone, a polycondensation product of ketones such as hydroxyacetophenone glycidyl ether, the above phenols and dicyclopentadiene, dipentene, Friedel-Crafts type reaction products such as glycidyl ether, aniline, aminophenol, aminometacresol, diaminodiphenylmethane, diaminodiphenyl ether, bis (aminophenoxy) benzene, bis (, and p-xylylene dichloride, bis (methoxymethyl) benzene Aminophenoxyphenyl) propane, phenylenediamine, toluenediamine, xylylenediamine, cyclohexene Sun, bis amine based epoxy resins derived from (aminomethyl) cyclohexane, and the like (including various kinds of isomers), p-oxy benzoic acid, m-
Glycidyl ester compounds derived from aromatic carboxylic acids such as oxybenzoic acid, terephthalic acid, and isophthalic acid, hydantoin epoxy compounds derived from 5,5-dimethylhydantoin, etc., 2,2-bis (3,4- Epoxycyclohexyl) propane, 2,2-bis [4- (2,3
-Epoxypropoxy) cyclohexyl] propane, vinylcyclohexenedioxide, alicyclic epoxy resin such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, etc., and one or more of these epoxy resins Is used. Among them, glycidyl ethers are preferable for encapsulating material applications, but in particular, polyhydric phenols obtained by condensation reaction of o-cresol novolac epoxy resin and methylbutylphenol and hydroxybenzaldehyde from the viewpoint of curability and moisture resistance. Preferred are divalent glycidyl ethers derived from glycidyl ether or tetramethylbiphenol or bis (4-hydroxy-3,5-dimethylphenyl) thioether, particularly o-
Cresol novolac epoxy resins are preferred.

The pulp as the component (b) used in the production method of the present invention is an ordinary natural or synthetic pulp. Pulp is a general term for fibrous materials that have been mechanically or chemically highly fibrillated. As such a pulp, the value of the specific surface area measured by the BET method preferably shows 3 to 20 / g, and JIS P-
The freeness value measured by the Canadian standard type method of 8121 "Pulp freeness test method" is preferably 100 to 700.
ml, more preferably 150 to 700 ml. As a raw material resin for these pulps, a natural or synthetic crystalline polymer is used, and examples thereof include aromatic polyamide resin, aliphatic polyamide resin, aliphatic or aromatic polyester resin, polyacrylonitrile resin, polyethylene resin, polypropylene resin. , Polyvinyl alcohol resin, and the like. Among these, aromatic polyamide resins, polyacrylonitrile resins and aromatic polyester resins are preferable from the viewpoint of heat resistance, and aromatic polyamide resins are particularly preferable.

In the present invention, the epoxy resin is 200 to
It is kneaded with pulp in a molten state so as to have a viscosity range of 10,000 centipoise. If the viscosity of the epoxy resin is 200 poise or less, the pulp cannot be dispersed uniformly, and if it is 10,000 poise or more, a large amount of power is required at the time of kneading, which is industrially disadvantageous, which is not preferable. .

The mixing ratio of the epoxy resin and the pulp is preferably 0.5 to 5 parts by weight of pulp with respect to 100 parts by weight of the epoxy resin. If the amount of pulp is 0.5 parts by weight or less, the desired toughness is not exhibited in the cured product, and if it is 5 parts by weight or more, the epoxy resin composition in which the pulp is dispersed has a high viscosity, and the production of the present composition Not only is the method difficult, but there is a problem with the moldability of the composition, which is not preferable.

The use of the epoxy resin composition obtained by the production method of the present invention in a resin composition for resin-sealed semiconductor will be described below. When using the epoxy resin composition obtained by the above-mentioned manufacturing method to obtain a resin composition for resin-encapsulated semiconductor, a curing agent, a curing accelerator, an inorganic filler, and various additions to the epoxy resin composition. The agent is blended. This compounding is usually carried out by a method of uniformly kneading using two heated rolls or the like.

Illustrative of the curing agents for this application are bisphenol A, tetrabromobisphenol A, bisphenol F, bisphenol S, bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) ethane, 1,3,3. -Trimethyl-1-m-hydroxyphenylindan-5 or 7-ol, 1,3,3-trimethyl-1-p-hydroxyphenylindan-6-ol, resorcin, hydroquinone, catechol and the above phenols and the above aldehydes or A polycondensate of the above ketones, or the above phenols and dicyclopentadiene, dipentene, p-xylylene dichloride,
Polyphenols such as Friedel-Crafts type reaction products with bis (methoxymethyl) benzene etc., maleic acid,
Phthalic acid, nadic acid, methyl-tetrahydrophthalic acid,
Polycarboxylic acid such as methyl nadic acid and its anhydride,
Polyamine compounds such as diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether, phenylenediamine, diaminodicyclohexylmethane, xylylenediamine, toluenediamine, diaminodicyclocyclohexane, dichloro-diaminodiphenylmethane (each containing isomers), ethylenediamine, hexamethylenediamine Further, active hydrogen-containing compounds capable of reacting with an epoxy group such as dicyandiamide and tetramethylguanidine can be exemplified, and one or more of these can be used. Preferred are polyhydric phenols, and more preferred are reaction products of phenol novolac, phenols and dicyclopentadiene, p-xylylene dichloride, or bis (methoxymethyl) benzene.

Explaining the mixing ratio of the epoxy resin and the curing agent, the amount of the curing agent used is 0.7 with respect to the epoxy group.
~ 1.2 equivalents. If the amount is less than 0.7 equivalent or more than 1.2 equivalent to the epoxy group, curing may be incomplete in any case, resulting in a problem in heat resistance.

As the curing accelerator, known curing accelerators can be used. Examples of such curing accelerators include organic phosphine compounds such as triphenylphosphine, tri-4-methylphenylphosphine, tri-4-methoxyphenylphosphine, tributylphosphine, trioctylphosphine, tri-2-cyanoethylphosphine, and triphosphine compounds. Tertiary amines such as butylamine, triethylamine, 1,8-diazabicyclo (5,4,0) undecene-7, triamylamine, and quaternary ammonium such as benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide, and triethylammonium tetraphenylborate. Examples thereof include salts and imidazoles, but are not limited to these. Among these, organic phosphine compounds, 1,8-diazabicyclo (5,4,0) undecene-7 and triethylammonium tetraphenylborate are preferable from the viewpoint of moisture resistance and curability, and among them, triphenylphosphine is particularly preferable.

As the inorganic filler, silica, alumina, titanium white, aluminum hydroxide, talc,
Examples thereof include clay and glass fiber, and silica (fused silica or synthetic silica) and alumina are particularly preferable. The blending ratio of the inorganic filler is 75 to 94% by weight in the total amount of the resin composition.
And preferably 80 to 92% by weight. When the amount of filler is small, the strength of the cured product when heated is low,
In addition, the amount of water absorption increases and the solder crack resistance is poor.
Further, when the amount of the filler is large, there is a problem in moldability, especially flowability. As the inorganic filler used in the present invention, various shapes such as spherical shape or crushed shape can be used, and several kinds of fillers having different sizes can be mixed and used. In particular, in order to achieve high filling of the inorganic filler as in the present invention, it is preferable to use at least one kind of spherical filler because the crushed filler alone has poor fluidity. In this case, the amount of spherical filler used is 1% by weight.
It is above, and preferably 10% by weight or more. However, when only the spherical filler is used, there is a problem in moldability such that the surface area is small and burrs are increased. Therefore, it is preferable to use the spherical filler and the crushed filler together.

In addition, if necessary, a natural wax, a synthetic wax, a higher fatty acid and a metal salt thereof, a releasing agent such as paraffin, a coloring agent such as carbon black, a surface treating agent such as a silane coupling agent, etc. You may add. Further, a flame retardant such as antimony trioxide, a phosphorus compound and a brominated epoxy resin may be added.
A brominated epoxy resin is particularly preferable for producing a flame retardant effect. Further, for example, in order to reduce the stress of the epoxy resin composition of the present invention, various elastomers may be added or preliminarily reacted to the extent that the curing of the present invention is not impaired. Specific examples thereof include addition type or reaction type elastomers such as polybutadiene, butadiene-acrylonitrile copolymer, silicone rubber and silicone oil. The epoxy resin composition according to the production method of the present invention has been described above for resin-encapsulated semiconductor use. However, since the cured product obtained from the epoxy resin composition of the present invention has excellent toughness, a matrix for composite materials, It is also useful for paints and other electronic parts.

[0015]

According to the present invention, a resin composition in which pulp is uniformly dispersed in an epoxy resin can be manufactured. The epoxy resin composition obtained by the method of the present invention is suitable for sealing a resin-sealed semiconductor device.

[0016]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. Example 1 As an epoxy resin, glycidyl ether of o-cresol novolac (trade name: Sumiepoxy ESCN-19)
5, 100 g of Sumitomo Chemical Co., Ltd.) and 3 g of aromatic amide resin pulp (trade name: Twaron SD03, Japan Aramid (with)) were weighed and placed in a three-necked flask. Then, the temperature was raised to 140 ° C. using an oil bath. The epoxy resin used in this experiment has a viscosity of 5 at 140 ° C.
It was 00 centipoise (viscosity measurement: Rheomat-30 manufactured by Contrabass). The mixture in the flask was stirred under a nitrogen atmosphere for 30 minutes. The stirring speed is 200 rp
It was m. Then, take out the obtained resin composition,
The dispersion state of the pulp was evaluated. The evaluation was performed by the NEP index advocated by DuPont. The evaluation method will be described in detail below.

11 g of the obtained resin composition comprising epoxy resin and pulp is weighed, placed on the center of a transparent glass plate, and another transparent glass plate is placed on it. In the center of the glass plate to be placed on top, cut 4 squares of 4 cm square. The glass plate placed on the top is pressed, and the resin composition is spread so as to form a circle having a diameter of about 15 cm, and the pills in the squares are classified according to size as shown in Table 1 and counted.

[0018]

[Table 1] If there are pills with a size of 5.1 mm or more, it is determined that they cannot be dispersed. Repeat this operation twice,
Calculate the EP index. NEP index = [(large number x 3) + (medium number x 2) +
(Small number × 1)] ÷ 2 From this formula, it was judged that the one having a small NEP index had good dispersibility.

The NEP index of the resin composition of Example 1 evaluated by the above evaluation method was 39. As a result, it was found that pulp was uniformly dispersed in this resin composition.
Moreover, the resin composition for semiconductor encapsulation was prepared by using the present resin composition according to the formulation shown in Table 2, and the solder heat resistance of the encapsulation IC was evaluated. The resin composition has a roll surface temperature of 60.
It was prepared here by kneading for 3 minutes with two rolls heated to ℃ and 110 ℃. Solder crack resistance is 52 pin QF
Transfer P package, 2.05mm thick
After molding and allowing it to absorb moisture under the conditions of 85 ° C./85% RH / 72 hours, it was immediately immersed in a solder bath at 240 ° C. for 30 seconds, and the number of cracked ICs was evaluated. The number of test individuals is 16.

Example 2 As the epoxy resin, 100 g of bisphenol A diglycidyl ether (trade name: Sumiepoxy ELA-128, manufactured by Sumitomo Chemical Co., Ltd.) and aromatic amide resin pulp (trade name: Twaron SD03, Japan Aramid (Yes)
5 g was weighed and placed in a three-necked flask in an atmosphere of 25 ° C. The epoxy resin used in this experiment had a viscosity of 8,000 at 25 ° C. (viscosity measurement: Rheomat-30 manufactured by Contrabass). The mixture was placed under a nitrogen atmosphere for 3
Stirred for 0 minutes. The stirring speed was 200 rpm. Then, the resin composition was taken out and the dispersion state of pulp was evaluated. The evaluation was performed by the above NEP index.
As a result, the NEP index was 12, and it was found that the pulp was uniformly dispersed.

Comparative Example 1 As an epoxy resin, glycidyl ether of o-cresol novolac (trade name: Sumiepoxy ESCN-195, manufactured by Sumitomo Chemical Co., Ltd.) which is solid at room temperature is used.
0 g and aromatic amide resin pulp (trade name: Twaron S
D03, Japanese aramid (with) 3 g were weighed and charged into a crushing mixer (sample mill SK-M10R manufactured by Kyoritsu Riko Co., Ltd.) at the same time as 20 g of dry ice, and 2,000 rpm
And pulverized and mixed for 5 minutes. The NEP index of the obtained resin composition was 150, and it was judged that the dispersion was poor. The solder cracking property is shown in Table 2 in the same manner as in Example 1 using the obtained resin composition.

Comparative Example 2 As an epoxy resin, 100 g of diglycidyl ether of bisphenol A (trade name: Sumiepoxy ELA-128, manufactured by Sumitomo Chemical Co., Ltd.) and aromatic amide resin pulp (trade name: Twaron SD03, Japan Aramid (Yes)
5 g was weighed and placed in a three-necked flask. Then, the temperature was raised to 80 ° C. using an oil bath. The epoxy resin used in this experiment had a viscosity of 20 centipoise at 80 ° C. (viscosity measurement: Contrabass Rheomat-
30). The mixture was stirred under a nitrogen atmosphere for 30 minutes. The stirring speed was 200 rpm. Then, the resin composition was taken out and the dispersion state of pulp was evaluated.
The evaluation was performed by the above NEP index. As a result, it was found that there were pills with a diameter of 5.1 or more and the dispersion was poor.

Comparative Example 3 As an epoxy resin, glycidyl ether of o-cresol novolak (trade name: Sumiepoxy ESCN-19) was used.
5, the Sumitomo Chemical Co., Ltd. product was used to evaluate the solder heat resistance of the pulp-free system according to the formulation shown in Table 2. The evaluation method was exactly the same as in Example 1. The results are shown in Table 2.

[0024]

[Table 2]

Continued Front Page (72) Inventor Noriaki Saito 6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd.

Claims (4)

[Claims] 1. In producing an epoxy resin composition comprising (a) an epoxy resin having two or more epoxy groups in a molecule and (b) pulp, the epoxy resin is melted,
A method for producing an epoxy resin composition, wherein the epoxy resin is kneaded with pulp in a viscosity range of 200 to 10,000 centipoise. 2. The epoxy resin is a glycidyl ether of o-cresol-novolak.
A method for producing the epoxy resin composition described. 3. The method for producing an epoxy resin composition according to claim 1, wherein the pulp is a pulp obtained from an aromatic polyimide resin. 4. The method for producing an epoxy resin composition according to claim 1, wherein the amount of pulp is 0.5 to 5 parts by weight with respect to 100 parts by weight of the epoxy resin.