JPH0573124B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an epoxy resin composition suitably used as a molding material, a powder coating material, a semiconductor encapsulating material, and the like. Prior art and problems to be solved by the invention Epoxy resins and epoxy resin compositions containing inorganic fillers, etc., generally have better moldability, adhesiveness, electrical properties, etc. than other thermosetting resins. Because of its excellent mechanical properties and moisture resistance, it is widely used as various molding materials, powder coating materials, electrical insulation materials, etc., and has recently attracted particular attention as a semiconductor encapsulating material. However, conventional epoxy resin compositions often crack during curing, which impairs the appearance of molded and painted surfaces and causes defects in semiconductor devices and other devices. The present inventors previously proposed an epoxy resin composition with excellent crack resistance by adding a block copolymer consisting of an aromatic polymer and an organopolysiloxane to a curable epoxy resin ( JP-A No. 58-21417) has excellent crack resistance, a low coefficient of expansion, a high glass transition point, and therefore a small amount of deformation during molding. There has been a desire for an epoxy resin composition that does not impair properties such as mechanical strength such as flexural modulus. The present invention was developed in view of the above circumstances, and has a low expansion coefficient, a high glass transition point, excellent crack resistance, and a moldable material without impairing mechanical strength represented by bending strength and bending modulus. It is an object of the present invention to provide an epoxy resin composition that has a small amount of deformation over time. Means and Action for Solving the Problems In order to achieve the above object, the present inventors have proposed that an epoxy resin composition containing a curable epoxy resin and a curing agent as main components to further improve crack resistance. As a result of intensive research on block copolymer components that bring about excellent effects, we found that an alkenyl group-containing epoxy resin and the following formula (1) H _a R _b SiO _4-(a+b)/2 ...(1) ( However, in the formula, R is an organic group, a is 0.001 to 0.1, b
is 1.9-2.0, 1.9<a+b<2.2. Also, 1
The number of silicon atoms in a molecule is an integer of 50 to 1000, and the number of hydrogen atoms directly bonded to a silicon atom in one molecule is an integer of 1 to 5. ) A long chain organopolysiloxane represented by the following formula (2) H _c R _d SiO _4-(c+d)/2 ...(2) (However, in the formula, R is an organic group and c is 0.02 to 1.0 ,d
is 1.8-2.0, 1.9<c+d<3. In addition, the number of silicon atoms in one molecule is an integer from 2 to 40, and 1
The number of hydrogen atoms directly connected to silicon atoms in the molecule is 1
It is an integer of ~5. ) Compound of formula (2)/compound of formula (1) = 0.01~
A copolymer obtained by addition reaction with an organopolysiloxane mixture mixed at a ratio of 0.4 or an alkenyl group-containing epoxy resin and the following formula (1) H _a R _b SiO _4-(a+b)/2 ... (1) (However, in the formula, R is an organic group, a is 0.001 to 0.1, b
is 1.9-2.0, 1.9<a+b<2.2. Also, 1
The number of silicon atoms in a molecule is an integer of 50 to 1000, and the number of hydrogen atoms directly bonded to a silicon atom in one molecule is an integer of 1 to 5. ) A copolymer obtained by an addition _reaction with _a long _- chain organopolysiloxane represented by ...(2) (However, in the formula, R is an organic group, c is 0.02 to 1.0, d
is 1.8-2.0, 1.9<c+d<3. In addition, the number of silicon atoms in one molecule is an integer from 2 to 40, and 1
The number of hydrogen atoms directly connected to silicon atoms in the molecule is 1
It is an integer of ~5. ) A copolymer mixture obtained by addition reaction with a short-chain organopolysiloxane ( It was found that it has certain characteristics. That is, when a copolymer with an alkenyl group-containing epoxy resin is obtained using an organopolysiloxane with a relatively low molecular weight of 3,000 to 7,000, the copolymer has poor compatibility with the epoxy resin matrix, resulting in phase separation. Easy to wake up. In contrast,
A copolymer obtained by subjecting an alkenyl group-containing epoxy resin to an addition reaction with an organopolysiloxane mixture obtained by mixing a long-chain organopolysiloxane of the above formula (1) and a short-chain organopolysiloxane of the above formula (2) in a specific ratio. , and a copolymer mixture obtained by adding organopolysiloxanes of formulas (1) and (2) to an epoxy resin containing alkenyl groups in a specific ratio, is a curable epoxy resin. The copolymer or the copolymer mixture can be uniformly dispersed in the resin, so when the copolymer or the copolymer mixture is blended into an epoxy resin composition, not only will the glass transition point not be lowered, but the epoxy resin composition will have a low expansion coefficient. The obtained copolymer or copolymer mixture has a high affinity for the curable epoxy resin because it contains the same or similar epoxy resin segment as the curable epoxy resin, and therefore microdispersion is possible. The inventors have discovered that it is possible to obtain an epoxy resin composition that dramatically improves crack resistance and further reduces the amount of deformation of aluminum electrodes due to stress generated during heat cycle tests, leading to the completion of the present invention. Therefore, the present invention provides an epoxy resin composition containing a curable epoxy resin, a curing agent, and an inorganic filler, and an alkenyl group-containing epoxy resin and the above (1).
A copolymer obtained by an addition reaction with an organopolysiloxane mixture obtained by mixing two types of organopolysiloxanes represented by formula and formula (2) at a weight ratio of (2)/(1) = 0.01 to 0.4. An epoxy resin composition is provided. Furthermore, the present invention provides a copolymer obtained by adding an alkenyl group-containing epoxy resin and an organopolysiloxane represented by the above formula (1) to an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler. The polymer () and the copolymer () obtained by the addition reaction of the alkenyl group-containing epoxy resin and the organopolysiloxane represented by the above formula (2) were mixed at a weight ratio of /=0.01 to 0.4. An epoxy resin composition characterized in that it contains a copolymer mixture is provided. Hereinafter, the epoxy resin constituting the composition of the present invention is an epoxy resin having two or more epoxy groups in one molecule, and this epoxy resin can be cured with various curing agents as described below. There are no particular restrictions on molecular structure, molecular weight, etc., and various conventionally known compounds can be used, including epoxy synthesized from epichlorohydrin and various novolac resins including bisphenols. Examples include resins, alicyclic epoxy resins, and epoxy resins into which halogen atoms such as chlorine and bromine atoms are introduced. Here, the above-mentioned epoxy resin is not necessarily limited to use of only one type, but may be used in combination of two or more types. In addition, when using the above-mentioned epoxy resin, there is no problem in appropriately using a monoepoxy compound in combination, and examples of the monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether,
Examples include allyl glycidyl ether, octylene oxide, and dodecene oxide. In addition, as curing agents, amine curing agents represented by diaminodiphenylmethane, diaminodiphenyl sulfone, metaphenylenediamine, etc., acid anhydrides such as phthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, etc. physical curing agent,
Alternatively, phenol novolak curing agents having two or more hydroxyl groups in one molecule such as phenol novolak and cresol novolak are exemplified. Furthermore, in the present invention, various curing accelerators such as imidazole or its derivatives, tertiary amine derivatives, phosphine derivatives, cycloamidine derivatives, etc. may be used in combination for the purpose of promoting the reaction between the above-mentioned curing agent and the epoxy resin. There is no problem. The amount of the curing agent used is the amount normally used, and the amount of the curing accelerator can also be within a normal range. The copolymer blended into the epoxy resin composition of the present invention is an alkenyl group-containing epoxy resin and the following formula (1) H _a R _b SiO _4-(a+b)/2 ...(1) (However, in the formula R is an organic group, a is 0.001-0.1, b
is 1.9-2.0, 1.9<a+b<2.2. Also, 1
The number of silicon atoms in a molecule is an integer of 50 to 1000, and the number of hydrogen atoms directly bonded to a silicon atom in one molecule is an integer of 1 to 5. ) and the following formula (2) H _c R _d SiO _4-(c+d)/2 ...(2) (However, in the formula, R is an organic group, c is 0.02 to 1.0, d
is 1.8 to 2.0, 1.9<c+d<3. In addition, the number of silicon atoms in one molecule is an integer from 2 to 40, and 1
The number of hydrogen atoms directly connected to silicon atoms in the molecule is 1
It is an integer of ~5. ) It is a reaction product obtained by addition reaction using two types of organopolysiloxanes shown in the following. Here, the alkenyl group-containing epoxy resin to be reacted with the organopolysiloxane is 1
Various epoxy resins having two or more alkenyl groups in the molecule are used, specifically, the following formula (3)
- (5) compounds etc. are mentioned.

[ka]

[ka]

[Case] (However, in the above formulas (3) to (5), p and q are usually 1<
20, an integer of 1≦q≦10. ) These alkenyl group-containing epoxy resins can be obtained by ordinary synthesis methods, such as by epoxidizing an alkenyl group-containing phenolic resin with epichlorohydrin, or by adding 2- to various known epoxy resins.
It can be easily obtained by partially reacting allylphenol or the like. In addition, in alkenyl group-containing epoxy resins, the hydrolyzable chlorine content is 1000 ppm or less,
In particular, it is preferably 700 ppm or less. If an alkenyl group-containing epoxy resin with a hydrolyzable chlorine content of more than 1000 ppm is used, the moisture resistance of the semiconductor sealed with the obtained epoxy resin may deteriorate. Further, the alkenyl group-containing epoxy resin preferably has an epoxy equivalent of 170 to 3000, particularly 200 to 280, and a softening point of 50 to 150°C, particularly 60 to 80°C. If the epoxy equivalent of the alkenyl group-containing epoxy resin falls outside the above range, it may adversely affect the curing characteristics of the resulting epoxy resin composition, the glass transition point (Tg), heat resistance, and electrical properties of the molded product. , Also, if the softening point is lower than 50°C, the glass transition point of the resulting composition will be low,
Heat resistance may decrease, and if the temperature exceeds 150°C, the melt viscosity of the composition may increase, resulting in poor workability. Furthermore, in the present invention, a long chain organopolysiloxane represented by the above formula (1) and a short chain organopolysiloxane represented by the above formula (2) are used together as the organopolysiloxane, and these two Any type of organopolysiloxane may be used as long as it has at least one SiH group in one molecule, but in particular, hydrodiene dimethylpolysiloxane at both ends, hydrodiene methylphenyl polysiloxane at both ends, Methyl(2-trimethoxysilylethyl)polysiloxane is preferred. Specifically, as the long chain organopolysiloxane of the above formula (1), the following compounds (6) to (10) may also be used.
Examples of the short chain organopolysiloxane of formula (2) include the following compounds (11) to (13).

【formula】

[ka]

【formula】

【formula】

【formula】

【formula】

[ka]

[Reference example]

Cresol novolac resin and allyl glycidyl ether are placed in a four-necked flask equipped with a reflux condenser, thermometer, stirrer, and dropping funnel and reacted, and then epichlorohydrin is added and reacted. An alkenyl group-containing cresol novolak epoxy resin (alkenyl equivalent: 1500, epoxy equivalent: 270, hydrolyzable chlorine: 700 ppm) was obtained. In a four-necked flask similar to the above, 120 g of the alkenyl group-containing cresol novolac epoxy resin obtained by the above method, 100 g of methyl isobutyl ketone, 200 g of toluene, and 0.04 g of a 2-ethylhexanol modified chloroplatinic acid solution with a 2% platinum concentration were added. Get in,
After 1 hour of azeotropic dehydration, 50 g of organopolysiloxane shown in Table 1 was added dropwise at reflux temperature for 30 hours.
After stirring for 4 hours at the same temperature to react, the resulting contents were washed with water and the solvent was distilled off under reduced pressure to produce the reaction products (common) shown in Table 1. Polymers A to O) were obtained. In Table 1, A to G are copolymers used in the present invention, and H to O are copolymers used as comparative products.

【table】

[Examples 1-7, Comparative Examples 1-8]

An epoxidized cresol novolak resin (curable epoxy resin) with an epoxy equivalent of 200 and a phenol novolak resin with a phenol equivalent of 110 were used in the amounts shown in Table 2, and among the copolymers obtained in the reference example, Blend 16 parts of those shown in Table 1, add 10 parts of brominated epoxy novolac resin
A mixture obtained by adding 260 parts of quartz powder, 1.5 parts of γ-glycidoxypropyltrimethoxysilane, 1.5 parts of wax E, and 1.0 parts of carbon black was uniformly melted and mixed with two hot rolls to obtain 15 parts of quartz powder. Seed epoxy resin compositions (Examples 1-7, Comparative Examples 1-8) were manufactured. Regarding these epoxy resin compositions, the following (a)
The various tests listed in ~(f) were conducted. (a) Spiral flow value: 175℃, using a mold that complies with FMMI standards.
Measured under the condition of 70Kg/cm ² . (b) Mechanical strength (bending strength and flexural modulus) According to JIS-K6911, a 10 x 4 x 100 mm transverse rod was formed at 175°C, 70 kg/cm ² and a forming time of 2 minutes.
Measurements were made on samples post-cured at 180°C for 4 hours. (c) Expansion coefficient, glass transition point Values were measured using a 4 mmφ x 15 mm test piece when the temperature was raised at a rate of 5° C. per minute using a dilatometer. (d) Cracking resistance Silicon chips with a size of 9.0 x 4.5 x 0.5 mm
It was adhered to a 14PIN-IC frame (42 alloy), an epoxy resin composition was molded onto it under molding conditions of 175℃ x 2 minutes, and after post-curing at 180℃ for 4 hours, -
A heat cycle of 196°C x 1 minute to 260°C x 30 seconds was repeatedly applied, and the resin crack occurrence rate was measured after 200 cycles (number of tests = 50). (e) Amount of deformation of aluminum electrode A deformation measuring element with an aluminum electrode deposited on a silicon chip with a size of 3.4 x 10.2 x 0.3 mm was used.
Bonded to a 14-pin IC frame (42 alloy) and molded the epoxy resin composition at 180℃.
After molding for 2 minutes and post-curing at 180℃ for 4 hours, heat cycles from -196℃ for 1 minute to 260℃ for 30 seconds were repeated, and the amount of deformation of the aluminum electrode after 200 cycles was investigated (test Number = 3). (F) Moisture resistance A sample molded into a 14-pin DIP IC shape.
They were placed in a high-pressure oven at 121°C and 100% humidity for 100 hours, and the open failure rate of the wiring was investigated. The results of the above tests are also listed in Table 2.

【table】

[Example 8, Comparative Example 9]

Organopolysiloxane copolymer (n=300) and organopolysiloxane copolymer O in Table 1
(n = 30) at a weight ratio /O = 0.23 (Example 8) and /O = 0.5 (Comparative Example 9) using copolymer mixtures (P) and (Q) obtained by mixing and blending, Epoxy resin compositions shown in Table 3 were produced in the same manner as in Example 1. Various tests (a) to (f) above were conducted using this epoxy resin composition. The results of the above tests are also listed in Table 3.

[Table] From the results in Table 3, the copolymer obtained by reacting the alkenyl group-containing epoxy resin of the present invention with a specific long-chain organopolysiloxane, and the copolymer obtained by reacting the alkenyl group-containing epoxy resin with a specific short-chain organopolysiloxane, Epoxy resin compositions containing a specific range of copolymers obtained by reaction with siloxane,
Compared to epoxy resin compositions containing the above two types of copolymers outside the specified range, the mechanical strength, expansion coefficient,
In addition to having the same glass transition point, it was confirmed that they were particularly excellent in crack resistance, deformation of the aluminum electrode, and moisture resistance.

Claims (1)

[Scope of Claims] 1. An epoxy resin composition containing an epoxy resin and a curing agent, which comprises an alkenyl group-containing epoxy resin and the following formula (1) H _a R _b SiO _4-(a+b)/2 ...( 1) (However, in the formula, R is an organic group, a is 0.001 to 0.1, b
is 1.9-2.0, 1.9<a+b<2.2. Also, 1
The number of silicon atoms in a molecule is an integer of 50 to 1000, and the number of hydrogen atoms directly bonded to a silicon atom in one molecule is an integer of 1 to 5. ) and the following formula (2) H _c R _d SiO _4-(c+d)/2 ...(2) (However, in the formula, R is an organic group, c is 0.02 to 1.0, d
is 1.8-2.0, 1.9<c+d<3. In addition, the number of silicon atoms in one molecule is an integer from 2 to 40, and 1
The number of hydrogen atoms directly connected to silicon atoms in the molecule is 1
It is an integer of ~5. ) Compound of formula (2)/compound of formula (1) = 0.01~
An epoxy resin composition characterized in that it contains a copolymer obtained by an addition reaction with an organopolysiloxane mixture mixed at a ratio of 0.4. 2. The epoxy resin composition according to claim 1, wherein the alkenyl group-containing epoxy resin has a hydrolyzable chlorine content of 1000 ppm or less. 3 Claim 1 containing an inorganic filler
The epoxy resin composition according to item 1 or 2. 4. In an epoxy resin composition containing an epoxy resin and a curing agent, an alkenyl group-containing epoxy resin and the following formula (1) H _a R _b SiO _4-(a+b)/2 ...(1) (However, the formula R is an organic group, a is 0.001-0.1, b
is 1.9-2.0, 1.9<a+b<2.2. Also,
The number of silicon atoms in one molecule is an integer of 50 to 1000, and the number of hydrogen atoms directly bonded to silicon atoms in one molecule is an integer of 1 to 5. ) A copolymer obtained by _an addition _reaction with _an organopolysiloxane represented by ) (However, in the formula, R is an organic group, c is 0.02 to 1.0, d
is 1.8-2.0, 1.9<c+d<3. In addition, the number of silicon atoms in one molecule is an integer from 2 to 40, and 1
The number of hydrogen atoms directly connected to silicon atoms in the molecule is 1
It is an integer of ~5. ) and a copolymer () obtained by addition reaction with organopolysiloxane shown in the weight ratio /
An epoxy resin composition comprising a copolymer mixture mixed in such a manner that the ratio of copolymers is 0.01 to 0.4. 5. The epoxy resin composition according to claim 4, wherein the alkenyl group-containing epoxy resin has a hydrolyzable chlorine content of 1000 ppm or less. 6. The epoxy resin composition according to claim 4 or 5, which contains an inorganic filler.