JPH0346486B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an epoxy resin composition that is particularly suitable for use in encapsulating semiconductor devices. Problems to be Solved by the Prior Art and the Invention Epoxy resin compositions containing epoxy resins, curing agents, and inorganic fillers generally have better moldability, adhesiveness, and electrical properties 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 recently it has been used in large quantities as a material for encapsulating semiconductor devices. . However, conventional epoxy resin compositions
Due to its high elastic modulus and poor flexibility, molding into elements,
It had defects such as cracks easily occurring during processing and heat cycle tests, and deterioration of function and damage of the element due to excessive stress and deformation of the element. . In order to solve these problems, the present inventors have developed an epoxy resin composition (Japanese Patent Application Laid-open No. 129246/1983) in which organopolysiloxane is blended with an epoxy resin as a curing agent.
Furthermore, he proposed an epoxy resin composition (Japanese Patent Application Laid-Open No. 58-21417) to which a block copolymer consisting of an aromatic polymer and an organopolysiloxane was added, thereby improving the crack resistance of the epoxy resin composition. Despite the improvement in crack resistance mentioned above,
In recent years, the requirements for materials for encapsulating semiconductor devices have become increasingly strict, and now there are materials that have superior crack resistance, a high glass transition point, a low coefficient of expansion, and do not impair bending strength. It is desired to develop a material with the following characteristics. Furthermore, the silicone-modified compounds used in the proposed epoxy resin composition are all expensive, which has a considerable impact on the price of the epoxy resin composition and, therefore, of various molded and processed products to which it is applied. In some cases, these prices became an obstacle to lowering prices. The present invention was developed in view of the above circumstances, and has excellent fluidity and mechanical strength such as bending strength and flexural modulus, as well as a low coefficient of expansion, a high glass transition temperature, and excellent crack resistance. The object of the present invention is to provide an economically advantageous epoxy resin composition. Means and Effects for Solving the Problems In order to achieve the above object, the present inventors have made extensive studies and have developed an epoxy resin composition containing a curable epoxy resin, a curing agent, and an inorganic filler. It has been discovered that a simple method of containing and compositing a specific organopolysiloxane gel is advantageous. That is, when an organopolysiloxane having two or more reactive functional groups in one molecule is blended and dispersed in the above-mentioned epoxy resin composition, the internal stress is lowered without lowering the glass transition point and the crack resistance is improved. In addition, this type of organopolysiloxane is relatively inexpensive and provides an economically advantageous epoxy resin composition. When a semiconductor device is encapsulated using an epoxy resin composition, the epoxy resin composition migrates to the interface with the lead frame, causing problems such as poor marking and poor adhesion. Furthermore, when an epoxy resin composition is stored in an uncured state for a long period of time, similar migration of organopolysiloxane and agglomeration of silicone dispersed particles occur, resulting in a significant change in dispersion. Problems such as difficulty in obtaining functions also arise. On the other hand, a hydrosilylation reaction (≡Si-CH= (addition reaction between CH ₂ and ≡Si-H) and slightly cross-linked, the consistency and elastic modulus in a specific range, that is, the consistency measured according to JIS-K2808 is 30.
~130 and a modulus of elasticity of 10 ³ to 10 ⁵ dynes/cm ² and dispersed in an epoxy resin composition, this type of organopolysiloxane does not migrate in the epoxy resin composition. In addition, the crack resistance is improved, and the fluidity and dispersion state of the epoxy resin composition do not deteriorate, which is observed when ordinary silicone rubber compounds are blended. It was discovered that various applied molding and processing can be performed relatively easily, and the present invention was completed. Therefore, the present invention provides an epoxy resin composition containing a curable epoxy resin, a curing agent, and an inorganic filler. Organopolysiloxane gel or organopolysiloxane gel having a consistency of 30 to 130 and an elastic modulus of 10 ³ to ^{10 5} dynes/cm ² as measured according to JIS-K2808, obtained by reaction with phenylhydrodiene polysiloxane. The present invention provides an epoxy resin composition containing a mixture of methylvinylpolysiloxane or methylphenylvinylpolysiloxane and methylhydrogenpolysiloxane or methylphenylhydrodiene dipolysiloxane that can form a siloxane gel. The present invention will be explained in more detail below. First, the curable epoxy resin constituting the epoxy resin 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 described below. There are no restrictions on molecular structure, molecular weight, etc.
Various conventionally known epoxy resins can be used, specifically, for example, novolac type epoxy resins synthesized from various novolac resins including epichlorohydrin and bisphenol A;
Examples include bisphenol A type epoxy resins, alicyclic epoxy resins, and substituted epoxy resins into which halogen atoms such as chlorine and bromine atoms are introduced, among which substituted or unsubstituted novolac type epoxy resins and bisphenol A type epoxy resins are used. suitable. 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. The above epoxy resin does not necessarily require 1
It is not limited to the use of only one type, and two or more types may be used in combination. In addition, as curing agents, amine curing agents such as diaminodiphenylmethane, diaminodiphenyl sulfone, metaphenylene diamine, etc., acid anhydrides such as phthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, etc. Examples include phenol novolak curing agents, or phenol novolak curing agents having two or more hydroxyl groups in one molecule, such as phenol novolak and cresol novolak. Furthermore, in the present invention, various curing accelerators such as imidazole or its derivatives,
There is no problem in using tertiary amine derivatives, phosphine derivatives, cycloamidine derivatives, etc. in combination. The amount of the curing agent used is a commonly used amount, and the amount of the curing accelerator can also be within a normal range. If the inorganic filler used in the present invention is less than 100 parts by weight per 100 parts by weight of the total amount of epoxy resin and curing agent, the expansion coefficient of the obtained epoxy resin composition is large and the result is satisfactory in terms of physical properties such as crack resistance. On the other hand, if it exceeds 1000 parts by weight, the fluidity may deteriorate and it may be difficult to disperse the inorganic filler, so it is preferably 100 to 1000 parts by weight, more preferably 250 parts by weight. ~750
Parts by weight. Note that there are no restrictions on the type of inorganic filler, whether it is used alone or in combination, and it may be selected appropriately depending on the purpose and use of the epoxy resin composition. , synthetic high-purity silica, synthetic spherical silica,
One or more selected from talc, mica, silicon nitride, silicon carbide, aluminum nitride, boron nitride, alumina, etc. can be used. The organopolysiloxane gel blended into the epoxy resin composition of the present invention is a temporarily crosslinked organopolysiloxane obtained by reacting organopolysiloxanes together through a hydrosilylation reaction and slightly crosslinking them, as described above. It is a siloxane with a consistency of 30 as measured according to JIS-K2808.
~130 and an elastic modulus of ¹⁰³ to ¹⁰⁵ dynes/ ^cm2 . The consistency of organopolysiloxane gel is
If the modulus is less than 30 or the modulus is 10 ³ dynes/cm ²
If it is less than 10%, although favorable results are obtained for the fluidity of the epoxy resin composition containing this organopolysiloxane gel, problems tend to occur in the sealing properties and printing properties of the epoxy resin composition after curing, and the machine It is not practical because it causes deterioration of the optical strength. On the other hand, if the organopolysiloxane gel consistency exceeds 130 or the elastic modulus
If it exceeds ¹⁰⁵ dynes/ ^cm2 , this will lead to a decrease in the fluidity and dispersibility of the epoxy resin composition containing this organopolysiloxane gel, and will also lead to a decrease in stress in the epoxy resin composition after curing. It is unsuitable for the purpose of the present invention because it cannot provide sufficient hardening and therefore cannot improve crack resistance. Here, the organopolysiloxane gel blended into the epoxy resin composition of the present invention includes methylvinylpolysiloxane or methylphenylvinylpolysiloxane, methylhydrodienepolysiloxane or methylphenylhydrodienepolysiloxane, and a platinum-based catalyst. In addition, it can be obtained by reaction curing. Organopolysiloxanes for obtaining such organopolysiloxanes include, for example, the following general formula (1) R _a SiO (4-a)/2 ... (1) where R is a hydrogen atom, a methyl group, or a vinyl group. or represents a phenyl group, and a is 1.5 to 2.05. )
Examples include organopolysiloxanes represented by: Specifically, the following formula ~ Me ₃ SiO _1/2 ... (hereinafter abbreviated as M) Me ₂ SiO ... (hereinafter abbreviated as D) HM _e2 SiO _1/2 ... (hereinafter abbreviated as D) (abbreviated as M ^H ) (CH ₂ = CH) MeSiO ... (hereinafter abbreviated as D ^V ) φ ₂ SiO ... (hereinafter abbreviated as D〓) (CH ₂ = CH) Me ₂ SiO _1/2 ... (hereinafter abbreviated as M ^V ) MeSiO _3/2 ... (hereinafter abbreviated as T) (Here, Me is a methyl group and φ is a phenyl group.) Organopolysiloxanes (1) to (5) in which two or more types of organosiloxanes are used as bonding units, and each organosiloxane bonding unit is bonded in the following ratio (mol%) Organopolysiloxane (1) M:D ^V :D =0.8:1.6:97.6 Organopolysiloxane (2) M:M ^V :T:D=4.03:0.75:5.62:89.60 Organopolysiloxane (3) M:D ^V ;D〓:D=0.8:1.6:1.6: 96.0 Organopolysiloxane (4) M ^H :D=10:90 Organopolysiloxane (5) M:D ^H :D=20:30:50 One or more of these may be used. In particular, it is preferable to use a methyl vinyl polysiloxane such as organopolysiloxanes (1) to (3) mentioned above as the organopolysiloxane, and use a methylhydrodiene organopolysiloxane as a crosslinking agent. An organopolysiloxane gel obtained by reacting vinyl polysiloxane and methylhydrodiene polysiloxane in the presence of a platinum catalyst can be suitably used as the organopolysiloxane gel according to the present invention. Among them, trimethylsilylmethylvinylpolysiloxane at both ends or trimethylsilylmethylvinyl phenylpolysiloxane at both ends is used as the methylvinylpolysiloxane, and hydrodiene methylpolysiloxane at both ends or hydrodienemethylphenylpolysiloxane at both ends is used as the methylhydrogen polysiloxane. It is more suitable for the purpose of the present invention. In addition, the blending amount of methylvinylpolysiloxane or methylphenylvinylpolysiloxane and methylhydrodienepolysiloxane or methylphenylhydrodienepolysiloxane to obtain the organopolysiloxane gel according to the present invention may be determined by mixing the two in an arbitrary ratio. Although there is no particular limitation, it is preferable to prepare the two so that the number of reactive functional groups in the two is approximately equal. In addition, in order to effectively achieve the purpose of the present invention, the amount of the organopolysiloxane gel according to the present invention is determined such that the total amount of the curable epoxy resin and the curing agent is 100%.
It is preferable to use 1 to 50 parts by weight, particularly 5 to 30 parts by weight, and when the above-mentioned amount is less than 1 part by weight, a stress reduction sufficient to contribute to the desired improvement in crack resistance is achieved. It is difficult to apply it, and if it exceeds 50 parts by weight, the mechanical strength of the cured epoxy resin composition tends to decrease, which is not preferable for the purpose of the present invention in either case. The epoxy resin composition of the present invention may further contain various additives depending on its purpose, use, etc., if necessary. For example, carbon-functional silanes to improve adhesion, waxes, release agents such as fatty acids such as stearic acid and their metal salts, pigments such as carbon black, dyes, antioxidants, flame retardants, γ-greens, etc. There is no problem in blending a surface treatment agent such as sidoxypropyltrimethoxysilane and other additives. Although there are no particular limitations on the method for producing the epoxy resin composition of the present invention, the following production methods (i) to (iv) can be suitably employed. (i) Methylvinylpolysiloxane, methylphenylvinylpolysiloxane, methylhydrogenpolysiloxane or methylphenylhydrodienepolysiloxane, and these A method in which an organopolysiloxane gel is reacted and formed simultaneously with curing of an epoxy resin composition by kneading a reaction catalyst. (ii) after reaction-forming an organopolysiloxane gel from methylvinylpolysiloxane or methylphenylvinylpolysiloxane, methylhydrodienepolysiloxane or methylphenylhydrodienepolysiloxane in a solution, optionally in the presence of a catalyst; A method in which the solvent is distilled off and the mixture is blended into an epoxy resin composition and kneaded. (iii) Add an inorganic filler such as silica to methyl vinyl polysiloxane, methyl phenyl vinyl polysiloxane, methyl hydrogen polysiloxane or methyl phenyl hydrogen polysiloxane, and if necessary in the presence of a catalyst, in a solution. An organopolysiloxane gel is reacted and formed by stirring and mixing, and this is adsorbed onto an inorganic filler. A method of blending and kneading into a resin composition. (iv) A combination of (i) to (iii) above, for example, using an organopolysiloxane gel-adsorbing inorganic filler obtained in the manufacturing process according to the manufacturing method (iii), and further (i) and/or
Or a method of obtaining an epoxy resin composition according to method (ii). The epoxy resin composition of the present invention is manufactured by uniformly stirring a predetermined amount of the above-mentioned components,
A kneader that has been mixed and preheated to 70-95℃,
Knead with rolls, extruders, etc., cool,
It can be obtained by methods such as crushing. In addition,
There is no particular restriction on the order of blending the components. The epoxy resin composition of the present invention can be suitably used as a molding material and a powder coating material, as well as IC,
It can also be effectively used for sealing semiconductor devices such as LSIs, transistors, thyristors, and diodes, and for manufacturing printed circuit boards. In the case of sealing the semiconductor device, conventionally used molding methods such as transfer molding, injection molding, and casting can be used. In this case, the molding temperature of the epoxy resin composition is preferably 150 to 180°C, and the post-curing is preferably performed at 150 to 180°C for 2 to 16 hours. Effects of the Invention As explained above, the epoxy resin composition of the present invention contains a curable epoxy resin, a curing agent, an inorganic filler, and a consistency of 30% as measured in accordance with JIS-K2808.
~130 and an elastic modulus of 10 ³ to 10 ⁵ dynes/cm ² or an organopolysiloxane mixture capable of forming the organopolysiloxane gel, thereby improving fluidity, bending strength, and flexural modulus. without compromising the mechanical strength of
It has a low expansion coefficient, a high glass transition temperature, excellent crack resistance, and when used for encapsulation of semiconductor devices, the amount of deformation of the aluminum electrode is small, and it is economically advantageous. An epoxy resin composition suitably used for commercial purposes etc. is obtained. EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples. In addition, prior to showing Examples and Comparative Examples, the following measurement items (a) to (e) adopted in Examples and Comparative Examples and their measurement methods, and manufacturing examples of organopolysiloxane gels will be shown. (a) Spiral flow value: 175℃, using a mold that complies with EMMI standards.
It was 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 temperature The 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 180℃ 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 50 cycles. (n=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 14PIN-IC frame (42 alloy) and molded the epoxy resin composition at 180℃.
After molding for 2 minutes and post-curing at 180°C for 4 hours, thermal cycles of -196°C x 1 minute to 150°C x 1 minute were repeated, and the amount of deformation of the aluminum electrode after 200 cycles was examined. (n=3) [Production Examples 1 to 7] The following formulas (A) to (C) as organopolysiloxanes The compounds represented by are mixed in the proportions shown in Table 1, a platinum catalyst 2-ethylhexanol-modified chloroplatinic acid with a platinum concentration of 10 ppm is added, and the mixture is heated at 150°C.
was heated for 30 minutes to produce organopolysiloxane. For the obtained organopolysiloxane gel,
Consistency was measured using a 1/4-inch micro-consistency meter in accordance with JIS-K2808, and elastic modulus was measured using a viscoelasticity spectrometer. The measurement results are included in Table 1.

【table】

[Examples 1-6, Comparative Examples 1-5]

Epoxidized cresol novolac resin with an epoxy equivalent of 200 (indicated by curable epoxy resin [ ] in the table), copolymer of allyl group-containing epoxidized novolac resin obtained by the following method and organopolysiloxane (indicated by copolymer in the table) ), phenol novolak resin with a phenol equivalent of 110, organopolysiloxane gels obtained in Production Examples 1 to 7 (organopolysiloxane gels [] to [] in the table)
Indicated by ), triphenylphosphine (TPP in the table)
Indicated by ), 1,8-diazabicycloundecene-
7 (indicated by DBU in the table) in the amounts shown in Table 2, and 7 parts of brominated epoxy novolac resin, 260 parts of fused silica powder, and 1.5 parts of 3-glycidoxypropyltrimethoxysilane. , 1.5 parts of Wax E, and 1.0 part of Carbon Black were uniformly melted and mixed using two heated rolls to obtain nine types of epoxy resin compositions (Examples 1 to 6, Comparative Examples 1 to 3). ) was manufactured. The copolymer of allyl group-containing epoxidized novolak resin and organopolysiloxane was prepared by placing 120 g of allyl group-containing epoxy resin, methyl 100g of isobutyl ketone, 200g of toluene, 2% platinum concentration
-Ethylhexanol modified chloroplatinic acid solution 0.04g
After stirring and heating, from the time it reaches reflux temperature, the organopolysiloxane is converted to the following formula:
(F) 80g of the compound represented by is added dropwise over a period of 30 minutes, and after the addition is complete, the reaction is further carried out at the same temperature for 4 hours, and the resulting content is washed with water and dried under reduced pressure. 150
It was a white-yellow opaque solid with a melt viscosity of 760 cp at °C. The various tests (a) to (e) described above were conducted on the epoxy resin composition obtained by the above method. The results are included in Table 2.

【table】

[Table] From the results in Table 2, the epoxy resin composition of Comparative Example 3, which does not contain organopolysiloxane gel, and Comparative Examples 1 and 2, which contain organopolysiloxane gels whose consistency or elastic modulus is outside the range of the present invention. In contrast, the epoxy resin compositions of the present invention had poor crack resistance and deformation of the aluminum electrode was observed, whereas the epoxy resin composition of the present invention exhibited no cracking and deformation of the aluminum electrode under the measurement conditions adopted. Moreover, the effects of the present invention were confirmed because the fluidity, mechanical strength as seen in bending strength and bending modulus, expansion coefficient, and glass transition temperature also cleared practical levels. In addition, comparative example 1
In the epoxy resin composition, silicone oozed out onto the surface of the molded product, resulting in poor appearance and poor marking.

Claims (1)

[Scope of Claims] 1. (a) a curable epoxy resin, (b) a curing agent, (c) an inorganic filler, and (d) methylvinylpolysiloxane or methylphenylvinylpolysiloxane and methylhydrogen polysiloxane. Obtained by reaction with siloxane or methylphenylhydrodiene polysiloxane, with a consistency of 30 to 130 and an elastic modulus of 10 ³ to 10 ⁵ dynes/cm ² as measured according to JIS-K2808.
or a mixture of methylvinylpolysiloxane or methylphenylvinylpolysiloxane and methylhydrogenpolysiloxane or methylphenylhydrodienepolysiloxane capable of forming the organopolysiloxane gel. An epoxy resin composition characterized by: 2. The epoxy resin composition according to claim 1, wherein the curable epoxy resin is one or more selected from substituted and unsubstituted novolak type epoxy resins and bisphenol A type epoxy resins. 3 Methylvinylpolysiloxane or methylphenylvinylpolysiloxane is trimethylsilylmethylvinylpolysiloxane or trimethylsilylmethylvinylphenylpolysiloxane at both ends, and methylhydrodienepolysiloxane or methylphenylhydrodienepolysiloxane is The epoxy resin composition according to claim 1, which is diene dimethyl polysiloxane or double-terminated hydrodiene methyl phenyl polysiloxane. 4. The epoxy according to any one of claims 1 to 3, wherein the amount of organopolysiloxane gel is 1 to 50 parts by weight per 100 parts by weight of the curable epoxy resin and curing agent. Resin composition. 5. The epoxy resin according to any one of claims 1 to 4, wherein the inorganic filler is blended in an amount of 100 to 1000 parts by weight per 100 parts by weight of the curable epoxy resin and curing agent. Composition.