JPH09176281A - Preparation of epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin compsn. which can provide a cured product containing low acetone insolubles and, at the same time, is excellent in all of curability, storage stability, flowability, and moldability. SOLUTION: This process for preparing an epoxy resin compsn. comprising an epoxy resin, a curing agent, an inorg. filler, and a curing catalyst comprises the steps of: heat melting and keneadhing the whole amt. of the epoxy resin, the curing agent, and the inorg. filler with 30 to 92wt.%, based on the whole amt., of the curing catalyst; pulverizing the kneaded product; and mixing the resultant powder with the remaining curing catalyst at a temp. below the melting temp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an epoxy resin composition which is preferably used for sealing semiconductor devices such as ICs, LSIs and transistors. The present invention relates to a method for producing an epoxy resin composition having excellent properties, fluidity and moldability.

[0002]

2. Description of the Related Art
In the semiconductor industry, resin-encapsulated diodes, transistors, ICs, LSIs, and VLSIs have become the mainstream. Among them, epoxy resins, curing agents, and epoxy resin compositions containing various additives are generally used. Since it is superior in moldability, adhesiveness, electrical characteristics, mechanical characteristics, and moisture resistance to other thermosetting resins, semiconductor devices are often sealed with epoxy resin compositions. Recently, the degree of integration of these semiconductor devices has been increased, and the chip size has been increased accordingly. On the other hand, the outer dimensions of the package are becoming smaller and thinner in accordance with the demand for smaller and lighter electronic devices. Furthermore, as for the method of mounting semiconductor components on a circuit board, surface mounting of semiconductor devices is becoming popular in order to increase the density of components on the board.

When the above-mentioned semiconductor device is surface-mounted, a method of immersing the entire semiconductor device in a solder bath or passing it through a high temperature zone in which the solder melts is generally used, but the thermal shock at that time causes a sealing resin layer. Cracks may occur, or peeling may occur at the interface between the lead frame or chip and the sealing resin. Such cracks and peeling become more remarkable when the sealing resin layer of the semiconductor device absorbs moisture before the thermal shock at the time of surface mounting. Therefore, the reliability of the semiconductor device sealed with the epoxy resin after mounting may be greatly impaired. Therefore, as a countermeasure against such popcorn, moisture absorption has been reduced by filling a high amount of filler. Further, in order to improve the moldability of a thin package, the viscosity of an epoxy resin composition has been reduced, and in order to further improve the productivity, a fast-curing catalyst has been studied for improving the molding cycle.

However, as a means for improving the productivity, when a conventional curing catalyst such as a tertiary amine compound, a tertiary phosphine compound or a derivative thereof is used in a large amount for rapid curing, the viscosity during kneading is increased. There are problems that the temperature becomes high, the amount of gelled substance increases, and the fluidity deteriorates.

Further, Japanese Patent Publication No. 7-16946 and Japanese Patent Publication No. 5
No. 2-135673 and Japanese Examined Patent Publication No. 59-129231 disclose epoxy resins, curing agents, inorganic fillers, release agents,
A method for producing an epoxy resin composition in which a pigment and a flame retardant are melt-kneaded and then a curing catalyst is added without melt-kneading is proposed, but the melt viscosity of the obtained epoxy resin composition is too low. There were problems such as occurrence of many burrs, deterioration of releasability, and easy occurrence of beard on the molding surface.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing an epoxy resin composition which is excellent in quick-curing property, storage stability, fluidity and moldability.

[0007]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that an epoxy resin, a curing agent, and an epoxy resin containing an inorganic filler as a main component. When a curing catalyst is added to the composition, 30 to 92% by weight of the total curing catalyst is an epoxy resin, a curing agent,
Melt and knead with the whole amount of the inorganic filler, and after finely pulverizing this mixture, the remaining curing catalyst is mixed without heating and melting, resulting in excellent fluidity, rapid curing, moldability, and less gelation. Further, they have found that an epoxy resin composition that gives a cured product having further excellent moisture resistance and adhesiveness can be obtained, and thus completed the present invention.

Therefore, the present invention provides a method for producing an epoxy resin composition containing an epoxy resin, a curing agent, an inorganic filler and a curing catalyst, wherein the total amount of the epoxy resin, the curing agent, the inorganic filler and the total amount of the curing catalyst are equal to each other. Out of 30
A method for producing an epoxy resin composition is provided, which comprises melt-kneading 92% by weight, finely pulverizing the kneaded product, and then mixing the rest of the curing catalyst at a temperature lower than the melting temperature thereof.

The method for producing the epoxy resin composition of the present invention will be described in more detail below. The epoxy resin used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule. , For example, orthocresol novolac type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin, bisphenol type epoxy resin, substituted or unsubstituted naphthalene type epoxy resin, substituted or unsubstituted biphenyl type epoxy resin, substituted or non-substituted Substituted triphenol alkane type epoxy resin,
Examples thereof include halides of the above epoxy resins, and one or more of these are appropriately selected and used.

As the curing agent, one corresponding to the epoxy resin is used, and for example, an acid anhydride type curing agent, a phenol type curing agent or the like can be used. Among them, the phenol type curing agent is used for the moldability of the composition. In view of moisture resistance, it can be preferably used. Specific examples of the phenol-based curing agent include at least two phenolic hydroxyl groups in one molecule of phenol novolac resin, cresol novolac resin, naphthalene type phenol resin, biphenyl type phenol resin, triphenol alkane type phenol resin, etc., preferably Include those containing three or more.

Here, the amount of the above-mentioned curing agent to be compounded is not particularly limited, but when a phenol-based curing agent is used, the molar ratio of the epoxy group in the epoxy resin to the phenolic hydroxyl group in the curing agent is not limited. The ratio is preferably in the range of 0.5 to 1.5, particularly 0.7 to 1.1.

The curing catalyst used in the present invention is added to accelerate the reaction between the epoxy resin and the curing agent, and the curing catalyst may be a known one.
1,8-diazabicyclo (5.4.0) undecene (D
BU) and other cycloamidine derivatives, phosphine derivatives,
Examples thereof include imidazole compounds, tertiary amines and the like, and one of these may be used alone or two or more thereof may be used in combination.

Specific examples of the phosphine derivative include triphenylphosphine, tributylphosphine, tricyclohexylphosphine, methyldiphenylphosphine,
Butylphenylphosphine, diphenylphosphine, phenylphosphine, octylphosphine, 1,2-bis (diphenylphosphino) ethane, bis (diphenylphosphino) methane, tetrabutylphosphonium tetraphenylborate, n-butyltriphenylphosphonium tetraphenyl Borate, tetraphenylphosphonium tetraphenylborate, trimethylphenylphosphonium tetraphenylborate, diethylmethylphenylphosphonium tetraphenylborate, diallylmethylphenylphosphonium tetraphenylborate, (2-hydroxyethyl) triphenylphosphonium tetraphenylborate, Ethyltriphenylphosphonium ・ Tetraphenylborate, Tetraphenylphosphonium ・Tiger ethyl borate, tetraphenylphosphonium-triethyl tetraphenylborate and the like.

Specific examples of the imidazole compound include 2
-Methylimidazole, 2-ethylimidazole, 2,
4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1-vinyl-2-methylimidazole, 2-phenylimidazole, 1-vinyl-2-ethylimidazole, imidazole , 2-phenyl-4-
Methylimidazole, 1-vinyl-2,4-dimethylimidazole, 1-vinyl-2-ethyl-1-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxy Methyl imidazole etc. are mentioned.

Specific examples of the tertiary amines include triethylamine, 2,4,6-dimethylmethylaminophenol, benzyldimethylamine, α-methylbenzylmethylamine, piperidine, dimethyllaurylamine, dialkylaminomethanolamine and tetramethyl. Guanidine, 2-dimethylamino-2-hydroxypropane,
Examples include N, N'-dimethylpiperazine, N-methylmorpholine, piperazine, 2- (dimethylaminomethyl) phenol, hexamethylenetetramine, 1-hydroxyethyl-2-heptadecylglyoxalidine.

The compounding amount (total weight) of the above curing catalyst is preferably 0.5 to 5.5 parts by weight, more preferably 0.6 to 0.5 parts by weight, based on 100 parts by weight of the total amount of the above epoxy resin and the above curing agent. 3.0 parts by weight. If the blending amount is less than 0.5 parts by weight, the cured product may be inferior in hot hardness, and if it is more than 5.5 parts by weight, it may be inferior in storage stability, gelation resistance and gelation amount. There is.

An inorganic filler is added to the epoxy resin composition of the present invention. Examples of the inorganic filler include fused silica, crystalline silica, alumina, talc, kaolin, silicon nitride, aluminum nitride, boron nitride and glass. Fibers and the like can be used, and fused silica and crystalline silica are preferably used. The amount of this inorganic filler compounded is
The total amount of the epoxy resin and the curing agent is preferably 200 to 850 parts by weight, more preferably 300 to 650 parts by weight, based on 100 parts by weight. If the blending amount is less than 200 parts by weight, the internal stress cannot be sufficiently reduced, and 8
If the amount is more than 50 parts by weight, the fluidity of the resin may be remarkably reduced and molding may be difficult.

Further, it is preferable that the surface of the above-mentioned inorganic filler is previously treated with a surface treating agent such as an organic silicon compound, titanates or organic aluminum before use. Among these, those called silane coupling agents typified by alkoxysilanes having a functional group such as an epoxy functional group, an acrylic functional group, an amino functional group, and a mercapto functional group are particularly preferable.

Further, in the present invention, it is preferable to add a silicone polymer or a thermoplastic polymer to the epoxy resin composition for the purpose of reducing the stress, and the addition of these polymers significantly reduces the generation of package cracks due to thermal shock. Can be made.

Examples of the silicone-based polymer include epoxy group, amino group, carboxyl group, hydroxyl group,
Silicone oil, silicone resin or silicone rubber having hydrosilyl group, vinyl group, etc., and further these silicone polymers and phenol novolac resin,
A copolymer with an organic polymer such as an epoxidized phenol novolac resin can be used. Further, fine powder of silicone rubber or gel can also be used. Examples of the thermoplastic polymer include MBS resin, butyral resin, and aromatic polyester resin.

The blending amount of these polymers is preferably 1 to 50 parts by weight based on 100 parts by weight of the total amount of the epoxy resin and the curing agent.

Further, in the present invention, a colorant, a releasing agent, a halogen trap agent, a flame retardant, a pigment and the like can be blended if necessary, and a known compound can be preferably used for the kind. it can.

In the case of producing an epoxy resin composition using the above components, first, the total amount of the epoxy resin, the curing agent, the inorganic filler and the total amount of the curing catalyst is 30 to 92% (% by weight, the same applies hereinafter), preferably Is melt-kneaded with 50-60%. In this case, if the amount of the curing catalyst to be melt-kneaded is less than 30% of the total amount, the reaction at the time of curing becomes slow, and the curability becomes insufficient, resulting in poor appearance of the molded product, poor curability of the cull portion, and burrs. And the hardness of the cured product becomes inferior in hot hardness. If it exceeds 92%, the reaction proceeds too much to produce a large amount of gelled product and unfilled problems occur.

The temperature during the melt kneading is not particularly limited, but is usually 60 to 130 ° C., preferably 80.
If the temperature is lower than 60 ° C, the viscosity becomes high and it becomes difficult to carry out kneading. If the temperature is higher than 130 ° C, the fluidity may be deteriorated to cause problems such as unfilling in moldability. is there.

The melt-kneading can be carried out using a kneader, a roll mill, a continuous kneader or the like, and the melt-kneading time is usually 0.5 to 5 minutes, especially 1 to 3 minutes.

After the melt-kneading, the kneaded product is cooled to room temperature (for example, about 0 to 30 ° C.) and then finely pulverized. The particle size of this fine powder is usually 75 μm
Although it is 1.4 mm, the preferable particle size distribution of the particle size of this fine powder is 20% or less for particles smaller than 75 μm, 7
5-40 μm is 10-40%, 180 μm
.About.500 .mu.m is 10-40%, 500 .mu.m-1.
0-50 mm is 20-50%, 1.0 mm-1.4 mm
10 to 40% of the above, 1 for larger than 1.4 mm
It is preferably 0% or less. The finer the particle size of this fine powder, the better the dispersibility of the curing catalyst to be added next, but if it is too fine, it may not be easy to tabletize the powdery epoxy resin composition obtained.

Next, the remaining curing catalyst, that is, 70 to 8%, preferably 50 to 40% of the total amount of the curing catalyst is added to and mixed with the finely pulverized product, and the addition amount of the curing catalyst is 70%. If it is more than 8%, the fluidity is deteriorated, and if it is less than 8%, the problem of poor curability may occur.

The preferable particle size distribution of the curing catalyst added and mixed here is usually 150 μm or less, for example, 1
To about 150 μm, more preferably 10 to 75 μm
By setting it to about m, the dispersibility of the remaining curing catalyst to be added becomes good. As a method for improving the dispersibility, a method of previously blending a curing catalyst with an epoxy resin component such as a pigment can be adopted.

This mixing is carried out without melting the mixture, that is to say below its melting temperature, preferably below 60 ° C., in particular 0-40 ° C. In addition, for this mixing,
A Henschel mixer, a V-blender or the like can be used, and the mixing time is usually 30 seconds to 10 minutes, particularly about 1 to 5 minutes in the case of a Henschel mixer, and usually 30 in the case of a V-blender. Minutes to 10 hours,
Especially, it is about 1 to 5 hours.

Components other than the epoxy resin, the curing agent, the inorganic filler, and the curing catalyst are preferably added at the time of the first melt-kneading, but as described above, the pigment and the like are added after the curing catalyst at the time of mixing. It is also possible to premix and add.

As described above, the epoxy resin composition obtained by the manufacturing method of the present invention is preferably used for sealing semiconductor devices such as ICs, LSIs, and transistors, and the semiconductor devices are sealed. In this case, a conventionally used molding method, for example, a transfer molding method, an injection molding method, a casting method or the like can be used. In this case, the molding temperature is preferably 150 to 180 ° C.

[0032]

According to the manufacturing method of the present invention, rapid curing,
It is possible to obtain an epoxy resin composition which is excellent in storage stability, fluidity, moldability, and has little gelation.

[0033]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. All parts shown below are parts by weight.

[Examples and Comparative Examples] Epoxy resin EOCN
1020 (softening point 65 ° C., manufactured by Nippon Kayaku Co., Ltd.) 60.2 parts,
Phenolic resin TD2093 (manufactured by Dainippon Ink and Chemicals, Inc.)
33.8 parts, wax E1.5 parts, carbon black 1
Parts, brominated epoxy resin 6 parts, antimony trioxide 7
Parts, fused silica powder 300 parts, γ-glycidoxypropyltrimethoxysilane 2 parts, and a predetermined amount of the curing catalyst shown in Table 1 uniformly at 90 to 100 ° C. using a two-roll mill. Melt and mix for 5 to 1 minute, cool to room temperature,
Finely pulverized to an average particle size of about 500 μm, and further mix the remaining amount of the curing catalyst (fine powder having an average particle size of about 30 to 70 μm) at room temperature (25 ° C.) to obtain a powdery epoxy resin composition. The thing was prepared.

Next, the epoxy resin composition obtained was
Then, various tests shown in the following (a) to (e) were conducted. result
Is also shown in Table 1. (A) Spiral flow 175 ° C, 70k using a mold conforming to EMMI standard
g / cm^Two It measured on condition of. (B) Hot hardness 175 ° C, 70kg / cm^Two , Molding time 90 seconds and 35
When a 10 × 4 × 100 mm bending bar is formed under the condition of seconds
The hot hardness of was measured with a Barcol hardness meter. (C) Storage stability Spiral flow value when each material is left at 25 ℃
Shows the number of days when is 80% of each initial value
Was. (D) Gelation time The gelation time of the composition was measured at 175 ° C. (E) Dissolution test Dissolve 100 g of the composition with 500 g of acetone, and use # 70.
Weigh the insoluble matter (gel-like substance) remaining on the sieve,
Was.

[0036]

[Table 1] 2PZ: 2-methylimidazole DBU: 1,8-diazabicyclo (5.4.0) undecene 2PHZ: 2-phenyl-4,5-dihydroxymethylimidazole TPP: triphenylphosphine

Front page continuation (72) Minoru Takei Minoru, Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture 10 Shinji Chemical Industry Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Toshio Shiobara Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture Address 1 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (2)

[Claims] 1. A method for producing an epoxy resin composition containing an epoxy resin, a curing agent, an inorganic filler and a curing catalyst, wherein the total amount of the epoxy resin, the curing agent, the inorganic filler and the total amount of the curing catalyst are 30 to 30%. 92% by weight is melt-kneaded, the kneaded product is finely pulverized, and then the rest of the curing catalyst is mixed at a temperature lower than the melting temperature of the epoxy resin composition. 2. The production method according to claim 1, wherein the total amount of the curing catalyst is 0.5 to 5.5 parts by weight based on 100 parts by weight of the total amount of the epoxy resin and the curing agent.