JPH06102749B2 - Epoxy resin composition and cured product thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin composition having excellent thermal shock resistance, which is suitably used as a component of various resin compositions, a modifier of various resins, and the like, and a cured product thereof. .

2. Description of the Related Art In recent years, various problems have occurred as semiconductor packages have become thinner. For example, when a flat package is mounted on a printed circuit board, the package is immersed in a high temperature solder bath, so that the conventional resin has a problem that the package is cracked by thermal shock.

Further, recently, it has been pointed out that when the package absorbs moisture before being mounted on a printed circuit board, when it is immersed in a high temperature solder bath, steam explosion occurs in the package and cracks occur.

However, various measures have been studied to improve both the frame and the resin as a measure against this kind of problem, but a perfect one has not yet been found.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an epoxy resin composition having excellent thermal shock resistance and a cured product thereof.

Means and Actions for Solving the Problems As a result of extensive studies conducted by the present inventor to achieve the above object, the following formula (1) (However, in the formula, X is a hydrogen atom or a halogen atom, and R is
Is an alkyl group, l and m are each an integer of 0 to 50, and l
When = 0, m is an integer from 1 to 50, and when m = 0, l is 1 to 50
Is an integer. ) An organopolysiloxane having at least two vinyl groups bonded to a silicon atom in one molecule and a hydrogen atom bonded to a silicon atom in at least one molecule in the t-butyl group-containing epoxy resin represented by By adding a dispersion of a cured product of a curable organopolysiloxane composition containing two organohydrogenpolysiloxanes and a platinum-based catalyst as main components to the epoxy resin composition as an epoxy resin, the composition is obtained. The present invention has been completed by finding that the product gives a cured product having excellent thermal shock resistance.

In this case, the epoxy resin having a t-butyl group is characterized in that the cured product of the organopolysiloxane is uniformly dispersed.
When the butyl group-containing epoxy resin is added to the epoxy resin composition, it exists as particles uniformly dispersed in the epoxy matrix, effectively acts as a shock absorber, and an epoxy resin composition having good impact resistance can be obtained. is there.

Accordingly, the present invention provides (a) an organopolysiloxane containing at least two vinyl groups bonded to a silicon atom in one molecule, and (b) a silicone resin in one molecule in the epoxy resin of the above formula (1). An epoxy resin obtained by dispersing a cured product of a curable organopolysiloxane composition containing (c) a platinum-based catalyst as a main component, and an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to elementary atoms. Provided is an epoxy resin composition characterized by containing it and a cured product thereof.

Hereinafter, the present invention will be described in more detail.

The epoxy resin composition of the present invention contains an epoxy resin, a curing agent, an inorganic filler, a curing catalyst, etc., and is a t-butyl group-containing epoxy in which a cured product of a specific organopolysiloxane described below is dispersed as an epoxy resin. Add resin.

Here, the epoxy resin used in the epoxy resin composition of the present invention has the following formula (1) Wherein X is hydrogen or a halogen atom, R is an alkyl group such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, n-hexyl group, An alkyl group having 1 to 6 carbon atoms such as a cyclohexyl group, l and m are each an integer of 0 to 50, and when l = 0, m
Is an integer of 1 to 50, and when m = 0, l is an integer of 1 to 50.

Specific examples of the t-butyl group-containing epoxy resin of the formula (1) include epoxy resins of the following formulas (2) to (4).

Further, it is desirable that these epoxy resins have a softening point of 50 to 100 ° C. and an epoxy equivalent of 100 to 400.

In the present invention, (a) a vinyl group-containing organopolysiloxane, (b) an organohydrogenpolysiloxane, and (c) a platinum-based catalyst are mainly added to the above-mentioned t-butyl group-containing epoxy resin of the formula (1). A cured product of the curable organopolysiloxane composition contained as a component is dispersed.

Here, the vinyl group-containing organopolysiloxane as the component (a) has at least two vinyl groups bonded to a silicon atom in one molecule. Examples of the organopolysiloxane include (CH ₂ ═CH) SiO _1.5 unit, R ¹ SiO _1.5
Unit, R ¹ (CH ₂ = CH) SiO unit, R ¹ ₂ SiO unit, R ¹ ₂ (CH ₂ =
CH) SiO _0.5 units, consists R ¹ ₂ SiO _0.5 units, R ¹ is a methyl group, an ethyl group, a propyl group, an alkyl group such as butyl group, a phenyl group, an aryl group such as a tolyl group, a cycloalkyl such as cyclohexyl group Groups, benzyl groups, aralkyl groups such as β-phenylethyl groups, or chloromethyl groups and 2-cyanoethyl groups in which some or all of the hydrogen atoms bonded to carbon atoms of these groups are replaced with halogen atoms, cyano groups, etc. C1 excluding aliphatic unsaturated groups such as vinyl group selected from 3,3,3,3-trifluoropropyl group
-10, Preferably it is a C1-C8 unsubstituted or substituted monovalent hydrocarbon group.

Furthermore, the molecular structure of this organopolysiloxane may be linear, molecular chain or cyclic. Also,
As this organopolysiloxane, a linear one having both ends of its molecular chain blocked with a dimethylvinylsilyl group, a divinylmethylsilyl group, a trivinylsilyl group, a vinylmethylphenylsilyl group or the like is preferable. The group may be contained in the chain, and the vinyl group content is 0.1
The content of the organic group other than the vinyl group is preferably 50% by mole or more, and the methyl group is preferably 50% by mole or more.

Specific examples of such vinyl group-containing organopolysiloxanes include those having the following structural formulas, which may be used alone or as a mixture of two or more kinds.

The vinyl group-containing organopolysiloxane may be added together with a vinyl group-containing compound such as allyl glycidyl ether, styrene, or a monomer such as glycidimemethacrylate, or an alkenyl group-containing epoxy resin. The amount can correspond to 0 to 50 mol% of the vinyl group based on the vinyl group of the group-containing organopolysiloxane.

Next, the organohydrogenpolysiloxane as the component (b) contains at least two hydrogen atoms bonded to silicon atoms in one molecule. Examples of this organohydrogenpolysiloxane include HSiO _1.5
Unit, R ² SiO _1.5 unit, R ² HSiO unit, R ² ₂ SiO unit, R ² ₂ HSi
O _0.5 unit, R ² ₃ SiO _0.5 unit, etc., and R ² is the above R ¹
The one selected from the same group is exemplified.

Further, this organohydrogenpolysiloxane is
The molecular structure may be linear, molecular chain or cyclic, and the hydrogen atom bonded to the silicon atom (≡Si
Generally, the H-bond) is preferably contained in the molecular chain, but may be at the end of the molecular chain. The amount of this ≡SiH bond is usually preferably 3 mol% or more, but it is preferable that 50 mol% or more of the organic groups other than the ≡SiH bond are methyl groups.

As such an organohydrogenpolysiloxane, those represented by the following formula are preferable.

The platinum-based catalyst of the component (c) is used for the addition reaction of the above-mentioned components (a) and (b), and known ones can be used. Specifically, platinum acid, Examples thereof include platinum or chloroplatinic acid supported on silica or the like, alcohol compounds of chloroplatinic acid, platinum compounds such as chloroplatinic acid and aldehydes, various olefins, and complex salts of vinylsiloxane.

The organopolysiloxane composition comprising the components (a), (b) and (c) can be obtained by mixing these predetermined amounts. In this case, the compounding ratio of the component (a) and the component (b) can be varied over a wide range depending on their molecular weight and the physical properties required as an elastomer after curing. It is desirable that the molar ratio of the vinyl group (≡SiCH = CH ₂ ) bonded to the silicon atom and the ≡SiH bond in the component (b) is in the range of 4: 1 to 1: 4. The amount of the component (c) added may be a catalytic amount, and is preferably 0.1 to 1000 ppm, particularly preferably 1 to 100 ppm with respect to the total amount of the components (a) and (b). If the addition amount of the component (c) is 0.1 ppm or less, this reaction may not be sufficient, and if it is 1000 ppm or more, the reaction may be too fast and uneconomical.

In the present invention, as a method for dispersing the cured product of the above-mentioned curable organopolysiloxane composition in the epoxy resin of the formula (1), for example, after dissolving the t-butyl group-containing epoxy resin of the formula (1), After adding a predetermined amount of the vinyl group-containing organopolysiloxane of the component (a) and the organohydrogenpolysiloxane of the component (b) to uniformly disperse the organopolysiloxane in the epoxy resin, It is preferable to add a platinum-based catalyst to cure the curable organopolysiloxane, and by this method, a cured product of the organopolysiloxane composition is obtained as particles uniformly dispersed in the epoxy matrix with a particle size of 50 microns or less. Exists.

In this case, the reaction temperature is 80 to 150 ° C, especially 100 to 120 ° C.
The reaction temperature is 0.5 to 6 hours, preferably 1 to 2 hours. If this reaction is carried out in a solvent such as toluene, the cured product of the organopolysiloxane may separate and may not be compatible with the epoxy resin. Therefore, the reaction system is preferably solventless.

The curable organopolysiloxane is used in an amount of 1 to 50 parts by weight, particularly 10 parts by weight, based on 100 parts by weight of the epoxy resin represented by the formula (1).
It is preferable to mix in an amount of up to 20 parts by weight. If the amount is less than 1 part by weight, sufficient impact resistance may not be obtained, and if it exceeds 50 parts by weight, mechanical strength may decrease. .

Further, in the present invention, it is possible to use other epoxy resin in addition to the epoxy resin of the formula (1). Examples of the other epoxy resin include bisphenol A type epoxy resin, novolac type epoxy resin, and alicyclic type. Epoxy resin,
Examples thereof include glycidyl type epoxy resin. Brominated epoxy resin may be used for flame retardancy.

Further, in the present invention, it is preferable to add a phenol resin as a curing agent for the epoxy resin, and the phenol resin has, for example, two or more phenolic hydroxyl groups such as phenol novolac resin, cresol novolac resin and triphenol methane. Is mentioned.
Further, in the present invention, among the phenolic resins, those having a softening point of 60 to 120 ° C. and a hydroxyl equivalent of 90 to 150 are desirable.

The amount of the phenolic resin used is preferably such that the equivalent ratio of the epoxy groups of the epoxy resin to the hydroxyl groups of the phenolic resin is in the range of 0.5 to 2, and any amount may be used as long as it is within this range. 3 for department
The amount is 0 to 100 parts by weight, preferably 40 to 70 parts by weight. If the amount used is less than 30 parts by weight, sufficient strength may not be obtained, while if it exceeds 100 parts by weight, unreacted phenol resin may remain and moisture resistance may be reduced.

Furthermore, it is preferable to add an inorganic filler to the epoxy resin composition of the present invention in order to reduce the expansion coefficient of the encapsulant and reduce the stress applied to the semiconductor element.

Here, as the inorganic filler, for example, crushed particles, fused silica having a spherical shape, crystalline silica, etc. are mainly used, but in addition to these, alumina, silicon nitride, aluminum nitride, etc. can also be used. is there. In order to achieve both low expansion of the cured product and moldability, it is better to use a blend of spherical and crushed products, or use only spherical products.

The average particle size of the inorganic filler is preferably 5 to 20 microns.

Furthermore, the filling amount of the inorganic filler is preferably 200 to 1600 parts by weight with respect to 100 parts by weight of the epoxy resin, and if it is less than 200 parts by weight, the expansion coefficient increases and the stress applied to the semiconductor element increases, resulting in deterioration of element characteristics. If it exceeds 1600 parts by weight, the viscosity at the time of molding becomes high and the moldability may deteriorate.

Furthermore, it is more preferable that the inorganic filler of this kind is surface-treated with a silane coupling agent in advance.

The composition of the present invention preferably contains, for example, imidazole or a derivative thereof, a phosphine derivative, a cycloamidine derivative and the like as a curing catalyst.

In this case, the compounding amount of the curing catalyst is preferably 0.001 to 5 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the epoxy resin, and if the compounding amount is less than 0.001 part by weight, it can be cured in a short time. If it exceeds 5 parts by weight, the curing rate may be too fast to obtain a good molded product.

A silicone-based flexibility-imparting agent such as a block polymer of an organic resin and a silicone polymer can be added to the epoxy resin composition of the present invention to reduce stress.

Usually, the amount of this type of stress reducing agent used is 0.5 to 10 of the total system.
%, Preferably 1 to 5%. If the amount used is less than 0.5%, sufficient impact resistance may not be given, and if it exceeds 10%, mechanical strength may become insufficient.

The composition of the present invention, if necessary, carnauba wax,
Release agents such as higher fatty acids and synthetic waxes, as well as silane coupling agents, antimony oxide and phosphorus compounds may be added.

The composition of the present invention can be produced by melt-kneading the above-mentioned components with a heating roll, melt-kneading with a kneader, melt-kneading with a continuous extruder, or the like.

INDUSTRIAL APPLICABILITY The epoxy resin composition of the present invention can be suitably used as a molding material and a powder coating material, as well as for encapsulating semiconductor devices such as ICs, LSIs, transistors, thyristors and diodes, and for manufacturing printed circuit boards. Can also be used effectively.

EFFECT OF THE INVENTION The epoxy resin composition of the present invention provides a cured product having high thermal shock resistance, excellent mechanical strength at high temperature and hot water resistance, and low stress and excellent workability. Therefore, the composition of the present invention sufficiently satisfies the use conditions of recent epoxy resin compositions and is effective as various electrical insulating materials, structural materials, adhesives, powder coating materials, semiconductor encapsulating materials, and the like. .

Next, prior to showing Examples and Comparative Examples, synthesis examples of components used in Examples and Comparative Examples will be shown.

[Synthesis Example 1] Epoxy resin containing t-butyl group ESX221 in a four-necked flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser.
(Sumitomo Chemical Co., Ltd.) 100g, 120 under nitrogen atmosphere
It was heated to 0 ° C. and dissolved. After dissolution, while stirring, 20 g of methylvinylpolysiloxane with a viscosity of 200cs consisting of 96 mol% of dimethylsiloxane units whose both ends are blocked with dimethylvinylsilyl groups and 4 mol% of methylvinylsiloxane units, both molecular chains Methylhydrogen siloxane unit 95 with ends blocked by trimethylsilyl groups
1 g of methylhydrogenpolysiloxane with a viscosity of 28 cs consisting of mol% and 5 mol% of dimethylsiloxane units was added. The molar ratio of ≡SiH / Si-CH = CH ₂ was 1.0.

After the addition, the mixture was stirred for 1 hour to uniformly disperse the organopolysiloxane, and then 0.06 g of chloroplatinic acid was added.

Chloroplatinic acid was added, and after stirring at 120 ° C. for 2 hours, 120 g of an epoxy resin (synthetic compound A) in which the cured organopolysiloxane was uniformly dispersed was obtained. This compound A has an epoxy equivalent
The viscosity was 257, the viscosity was 730 cs, and the average particle size of the cured organopolysiloxane was 5 μm.

[Synthesis Example 2] A t-butyl group-containing epoxy resin ESX221 was placed in a four-necked flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser.
(Sumitomo Chemical Co., Ltd.) 100g, 120 under nitrogen atmosphere
It was heated to 0 ° C. and dissolved. After dissolution, while stirring, 20 g of methylvinylpolysiloxane having a viscosity of 600 cs and consisting of 100 mol% of dimethylsiloxane units whose both molecular chain ends are blocked with dimethylvinylsilyl groups, dimethylhydrogensiloxane unit [(CH ₃ ) ₂ 1.0 g of methylhydrogenpolysiloxane consisting of 60 mol% HSiO _0.5 ] and 40 mol% SiO ₂ units was added. The molar ratio of ≡SiH / Si-CH = CH ₂ was 1.0.

After the addition, the mixture was stirred for 1 hour to uniformly disperse the organopolysiloxane, and then 0.06 g of chloroplatinic acid was added.

Chloroplatinic acid was added and the mixture was stirred at 120 ° C. for 2 hours to obtain 118 g of an epoxy resin (synthetic product B) in which the cured organopolysiloxane was uniformly dispersed. This compound B has an epoxy equivalent
The viscosity was 256, the viscosity was 1080cs, and the average particle size of the cured organopolysiloxane was 8 μm.

[Synthesis Example 3] A t-butyl group-containing epoxy resin ESX221 was placed in a four-necked flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser.
(Sumitomo Chemical Co., Ltd.) 100g, 120 under nitrogen atmosphere
It was heated to 0 ° C. and dissolved. After dissolution, while stirring, 10 g of methyl vinyl siloxane with a viscosity of 600 cs consisting of 100 mol% of dimethyl siloxane units in which both ends of the molecular chain are blocked with dimethyl vinyl silyl groups, allyl glycidyl ether 5
g, dimethyl hydrogen siloxane unit [(CH ₃ ) ₂ HSi
2.0 g of methylhydrogenpolysiloxane consisting of 60 mol% of O _0.5 ] and 40 mol% of SiO ₂ unit was added.

After the addition, the mixture was stirred for 1 hour to uniformly disperse the organopolysiloxane, and then 0.06 g of chloroplatinic acid was added.

After adding chloroplatinic acid and stirring at 120 ° C. for 2 hours, 119 g of an epoxy resin (Compound C) in which the cured organopolysiloxane was uniformly dispersed was obtained. This compound C has an epoxy equivalent
226, viscosity 1051cs, average particle size of the cured organopolysiloxane was 5 μm.

[Synthesis Example 4] A synthetic product D was obtained in the same manner as in Synthesis Example 1 using an epoxidized orthocresol novolac resin (EOCN1020 (65), manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin. The cured organopolysiloxane of this composition was non-uniformly dispersed and had an average particle size of 200 μm.

[Synthesis Example 5] Bisphenol type epoxy resin (RE
A compound E was obtained in the same manner as in Synthesis Example 1 using 310S, manufactured by Nippon Kayaku Co., Ltd. The cured organopolysiloxane of this composite E was non-uniformly dispersed and had an average particle size of 250 μm.

[Synthesis Example 6] A synthetic product F was obtained in the same manner as in Synthesis Example 1 using epoxidized triphenolmethane (EPPN501H, manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin. The cured organopolysiloxane of Compound F was non-uniformly dispersed and had an average particle size of 350.
was μm.

[Synthesis Example 7] To a four-necked flask equipped with a reflux condenser, a thermometer, and a nitrogen inlet tube, 200 ml of toluene and the organopolysiloxane used in Synthesis Example 2 (100 g of methylvinylsiloxane, 5 g of methylhydrogenpolysiloxane, Chloroplatinic acid (0.3 g) was added, and the mixture was reacted at 110 ° C for 6 hours. After 6 hours, the solvent was removed to obtain a solid product of cured organopolysiloxane (synthetic product G). This solid was crushed and used for the epoxy resin composition of Comparative Example 5.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
In the following examples, all parts are parts by weight.

[Examples and comparative examples]

In addition to the components shown in Table 1, 1.5 parts of γ-glycidoxyprobiyl trimethoxysilane, 1.0 part of carbon black, and 8 parts of triphenylphosphine were added, and the resulting blend was melt mixed with a hot two-roll mill. , 17 kinds of epoxy resin compositions (Examples 1 to 11 and Comparative Examples 1 to 6) were obtained.

A mixture (mixture A) of the organopolysiloxane used in Synthesis Example 1 (100 g of methyl vinyl siloxane, 5 g of methyl hydrogen polysiloxane, 0.3 g of chloroplatinic acid) was used as an epoxy resin as it was.

Regarding these epoxy resin compositions, the following (a) to
Various characteristics of (e) were measured.

(A) Spiral flow Using a mold conforming to the EMMI standard, measurement was performed under the conditions of 175 ° C. and 70 kg / cm ² .

(B) Mechanical strength (flexural strength, flexural modulus) According to JIS K6911, a 10 × 100 × 4 mm bending bar was molded under the conditions of 175 ℃, 70 kg / cm ² , molding time of 2 minutes, and 180 ℃ 4 It was measured with a post-cured material for a period of time.

(C) Glass transition temperature, expansion coefficient of 175 ° C, 70 kg / cm ² , molding time of 2 minutes, 4 × 4 × 15 mm test piece was molded, and post-cured at 180 ° C for 4 hours. It was measured by raising the temperature at 5 ° C. per minute with a meter.

(D) Solder cracking and moisture resistance after moisture absorption Moisture resistance test for aluminum wiring corrosion measurement under the conditions of 175 ° C, 70kg / cm ² and molding time of 2 minutes. A semiconductor device is sealed in a flat package with a thickness of 2mm. Post-cure at 180 ° C. for 4 hours. 72 this package in the atmosphere of 85 ℃ / 85% RH
After being left for a period of time to perform a moisture absorption treatment, this was immersed in a solder bath at 260 ° C. for 10 seconds. After confirming the crack occurrence rate of the package generated at this time, only the non-defective product was left in a saturated steam atmosphere at 120 ° C. for 400 hours to examine the defect occurrence rate.

(E) Adhesiveness 175 ℃, 70kg / c in a cylindrical shape with 15mmφ and 5mm height on 42 alloy plate
After molding under conditions of m ² and molding time of 2 minutes and post-curing at 180 ° C. for 4 hours, the peeling force between the molded product and the 42 alloy plate was measured with a bush bull gauge.

From the results of Table 1, a t-butyl group-containing epoxy resin composition in which a cured organopolysiloxane obtained by reacting a curable organopolysiloxane in a molten state of a t-butyl group-containing epoxy resin is uniformly dispersed (Examples 1
It was confirmed that the materials No. 11 to 11) have excellent effects on bending strength, solder cracks after moisture absorption, and adhesiveness.

Continuation of front page (56) Reference JP-A-2-227423 (JP, A) JP-A-2-191659 (JP, A) JP-A-2-182746 (JP, A) JP-A-1-256514 (JP , A) JP 62-187721 (JP, A) JP 2-212514 (JP, A) JP 2-208314 (JP, A) JP 2-208313 (JP, A)

Claims (2)

[Claims] 1. The following formula (1) (In the formula, X is a hydrogen atom or a halogen atom, R is an alkyl group, t-Bu is a t-butyl group, and l and m are 0 respectively.
Is an integer of -50, and when l = 0, m is an integer of 1-50, m
When = 0, l is an integer of 1 to 50. ) In the epoxy resin represented by, (a) an organopolysiloxane containing at least two vinyl groups bonded to a silicon atom in one molecule, and (b) a hydrogen atom bonded to a silicon atom in one molecule. And an epoxy resin obtained by dispersing a cured product of a curable organopolysiloxane composition containing (c) a platinum-based catalyst as a main component. Epoxy resin composition. 2. A cured product obtained by curing the composition according to claim 1.