JP3309688B2 - Method for producing epoxy resin composition - Google Patents

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 suitably used for encapsulating semiconductor devices such as ICs, LSIs, transistors, and the like. 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-sealed diodes, transistors, ICs, LSIs, and super LSIs have become the mainstream. Among them, epoxy resins, curing agents, and epoxy resin compositions containing various additives have been generally used. Compared with other thermosetting resins, they are excellent in moldability, adhesiveness, electrical properties, mechanical properties, moisture resistance and the like, and therefore, semiconductor devices are often sealed with an epoxy resin composition. Recently, the degree of integration of these semiconductor devices is increasing, and the chip size is correspondingly increasing. On the other hand, the external dimensions of the package have been reduced in size and thickness in accordance with the demand for smaller and lighter electronic devices. Further, a method of attaching a semiconductor component to a circuit board has been frequently used for surface mounting of a semiconductor device in order to increase the density of components on the board.

When the above-mentioned semiconductor device is surface-mounted, it is common to immerse the entire semiconductor device in a solder bath or to pass the semiconductor device through a high-temperature zone in which the solder melts. Cracks occur, or separation occurs 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. For this reason, as a countermeasure against such popcorn, low moisture absorption has been performed by high filling of the filler. Further, the viscosity of the epoxy resin composition has been reduced in order to improve the moldability of a thin package, and a fast-curing catalyst has been studied to improve the molding cycle in order to further improve the productivity.

However, as a means for improving the productivity, when a conventional curing catalyst, for example, a tertiary amine compound, a tertiary phosphine compound or a derivative thereof is used in many cases to make it quick-curing, the viscosity during kneading is reduced. However, there are problems such as an increase in the amount of gelation, an increase in the amount of gelled matter, and deterioration in fluidity.

Also, Japanese Patent Publication No. Hei 7-16946,
2-135673 and JP-A-59-129231 disclose epoxy resins, curing agents, inorganic fillers, release agents,
Pigment, after melt-kneading the flame retardant, a method of manufacturing an epoxy resin composition is added without adding a curing catalyst without melt-kneading, but the melt viscosity of the obtained epoxy resin composition is too low. There were problems such as generation of many burrs, deterioration of releasability, and easy formation of whiskers 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 having excellent curing properties, storage stability, fluidity, and moldability.

[0007]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that an epoxy resin containing an epoxy resin, a curing agent, and an inorganic filler as main components is provided. When a curing catalyst is added to the composition, 30 to 92% by weight of the total curing catalyst is used as an epoxy resin, a curing agent,
Melt kneading with the entire amount of inorganic filler, finely pulverizing this mixture, and mixing without heating and melting the remaining curing catalyst, excellent fluidity, rapid curability, excellent moldability, less gelation Further, the present inventors have found that an epoxy resin composition which gives a cured product excellent in moisture resistance and adhesion can be obtained, and the present invention has been accomplished.

Accordingly, the present invention relates to 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 ~
92% by weight, and then kneading the mixture, pulverizing the mixture, and then mixing the remainder of the curing catalyst with the mixture at a temperature lower than the melting temperature of the mixture. provide.

Hereinafter, the method for producing the epoxy resin composition of the present invention will be described in more detail. 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, ortho-cresol novolak type epoxy resin, phenol novolak 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 unsubstituted Substituted triphenol alkane type epoxy resin,
The above-mentioned epoxy resin halides and the like can be mentioned, and one or more of these may be appropriately selected and used.

As the curing agent, one corresponding to the epoxy resin is used. For example, an acid anhydride-based curing agent, a phenol-based curing agent and the like can be used. And moisture resistance. Specifically, as the phenolic curing agent, at least two phenolic hydroxyl groups in one molecule of a phenol novolak resin, a cresol novolak resin, a naphthalene-type phenol resin, a biphenyl-type phenol resin, a triphenol-alkane-type phenol resin, and the like are preferable. Include three or more.

The amount of the curing agent is not particularly limited, but when a phenolic 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 used. It is preferable that the ratio be in the range of about 0.5 to 1.5, particularly about 0.7 to 1.1.

The curing catalyst used in the present invention is added for accelerating the reaction between the epoxy resin and the curing agent. 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 an imidazole compound and tertiary amines, and one of these can be used alone or two or more can 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:
-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 and the like can be mentioned.

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

The amount (total weight) of the curing catalyst is preferably 0.5 to 5.5 parts by weight, more preferably 0.6 to 5.5 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the curing agent. 3.0 parts by weight. If the amount is less than 0.5 part by weight, the cured product may have poor hot hardness. If the amount is more than 5.5 parts by weight, the storage stability and the gelation resistance may be poor, and the amount of the gelled material may increase. There is.

The epoxy resin composition of the present invention contains an inorganic filler. Examples of the inorganic filler include fused silica, crystalline silica, alumina, talc, kaolin, silicon nitride, aluminum nitride, boron nitride and glass. Fiber or the like can be used, and preferably, fused silica or crystalline silica is used. The compounding amount of this inorganic filler is
It is preferably 200 to 850 parts by weight, particularly preferably 300 to 650 parts by weight, based on 100 parts by weight of the total amount of the epoxy resin and the curing agent. If the 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.

When using the above-mentioned inorganic filler, it is preferable to use the inorganic filler after previously treating its surface with a surface treating agent such as an organic silicon compound, titanates or organic aluminums. Among these, for example, a so-called silane coupling agent represented by an alkoxysilane having a functional group such as an epoxy functional group, an acrylic functional group, an amino functional group, and a mercapto functional group is particularly desirable.

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

Examples of the silicone polymer include an epoxy group, an amino group, a carboxyl group, a hydroxyl group,
Hydrosilyl group, silicone oil having a vinyl group, silicone resin or silicone rubber, furthermore, these silicone polymer and phenol novolak resin,
A copolymer with an organic polymer such as an epoxidized phenol novolak resin can be used. Further, fine powder of silicone rubber or gel can also be used. Examples of the thermoplastic polymer include an MBS resin, a butyral resin, and an aromatic polyester resin.

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

In the present invention, a coloring agent, a releasing agent, a halogen trapping agent, a flame retardant, a pigment and the like can be blended as required, and known compounds can be suitably used. 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 above curing catalyst are 30 to 92% (% by weight, hereinafter the same), preferably Is melt-kneaded with 50 to 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, the curability becomes insufficient, and the appearance of the molded product is poor, the curl portion has poor curability, and the In addition, when the content exceeds 92%, the reaction proceeds too much to generate a large amount of gelled product, or unfilled.

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

The melt-kneading can be carried out by 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 from 75 μm
Although it is 1.4 mm, a preferable particle size distribution of the particle size of the fine powder is 20% or less when the particle size is smaller than 75 μm,
10 to 40% of those with 5 μm to 180 μm, 180 μm
10 to 40% for those having a thickness of 500 μm to 500 μm.
20mm 50%, 1.0mm ~ 1.4mm for 0mm
10% to 40%, 1.4mm larger than 1
It is preferably 0% or less. The finer the particle size, the better the dispersibility of the curing catalyst to be added next. However, if the fineness is too small, it may not be easy to make the resulting powdery epoxy resin composition into tablets.

Next, the remaining hardening catalyst, that is, 70 to 8%, preferably 50 to 40% of the total amount of the hardening catalyst is added to the finely pulverized product, and the hardening catalyst is added in an amount of 70%. If the amount is more than the above, the fluidity becomes poor. If the amount is less than 8%, a problem of poor curing may occur.

The preferred particle size distribution of the curing catalyst to be added and mixed here is usually 150 μm or less, for example, 1 μm or less.
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 in which a curing catalyst is previously blended with an epoxy resin component such as a pigment can be adopted.

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

The 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. Can be added in advance.

The epoxy resin composition obtained by the production method of the present invention is suitably used for encapsulating semiconductor devices such as ICs, LSIs, and transistors, and performs encapsulation of semiconductor devices. In this case, a molding method conventionally used, for example, a transfer molding method, an injection molding method, a casting method, or the like can be used. The molding temperature in this case is desirably set at 150 to 180 ° C.

[0032]

According to the production method of the present invention, rapid curability,
An epoxy resin composition having excellent storage stability, fluidity, and moldability, and having little gelling can be obtained.

[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. In addition, all the parts shown below are parts by weight.

[Examples and Comparative Examples] Epoxy resin EOCN
1020 (softening point 65 ° C, 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, 300 parts of fused quartz powder, 2 parts of γ-glycidoxypropyltrimethoxysilane, and a predetermined amount of the curing catalyst shown in Table 1 using a two-roll mill at 90 to 100 ° C. to a uniform amount of about 0.1 part. After melt-mixing for 5 to 1 minute and cooling to room temperature,
Finely pulverized to an average particle size of about 500 μm, and the remaining amount of the curing catalyst (fine powder having an average particle size of about 30 to 70 μm) is mixed at room temperature (25 ° C.) to obtain a powdery epoxy resin composition. Was prepared.

Next, with respect to the obtained epoxy resin composition,
Then, various tests shown in the following (a) to (e) were performed. result
Are 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 x 4 x 100 mm bending rod is formed in seconds
Was measured with a Barcol hardness tester. (C) Storage stability Spiral flow value when each material is left at 25 ° C
Shows the number of days when the value of each is 80% of the initial value
Was. (D) Gelation time The gelation time of the composition was measured at 175 ° C. (E) Dissolution test 100 g of the composition was dissolved with 500 g of acetone, and # 70
Measure the weight of insoluble matter (gel) remaining on the screen
Was.

[0036]

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

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Takei 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside Silicone Electronics Materials Research Laboratory Shin-Etsu Chemical Co., Ltd. (72) Inventor Toshio Shiobara Matsui, Usui-gun, Gunma Prefecture Hitomi Tamachi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (56) References JP-A-3-19564 (JP, A) JP-A-3-211 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) C08L 63/00-63/10 C08J 3/20

Claims (3)

(57) [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 30 to 30% of the total amount of the epoxy resin, the curing agent, the inorganic filler and the total amount of the curing catalyst. A method for producing an epoxy resin composition, comprising melt-kneading 92% by weight, kneading the kneaded material, pulverizing the kneaded material, and mixing the remaining portion of the curing catalyst at a temperature lower than the melting temperature of the kneaded material. 2. The 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. 3. The production method according to claim 1, wherein the kneaded product is finely pulverized to a particle size of 75 μm to 1.4 nm, and then the remainder of the curing catalyst is mixed to a particle size of 150 μm or less.