JPS6228968B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention aims to provide an epoxy resin composition, particularly a composition suitable for encapsulating electronic components, which has excellent moisture resistance and can yield highly reliable products. When compared to conventional ceramic and can-sealed semiconductor devices, recent semiconductor devices are increasingly being molded into resin-sealed devices, which are superior in mass productivity and provide products at lower prices. As this sealing resin, epoxy resin is increasingly being used because of its excellent electrical properties, mechanical properties, and the like. However, semiconductor devices sealed with resins such as epoxy resins are more hygroscopic than ceramic or can-sealed types, and are also less prone to water intrusion through the interface between the resin and the frame. The problem is that there are too many. On the other hand, ionic impurities such as hydrolyzable Cl remain in the sealing resin, and these interact with water to increase the leakage current of semiconductor devices and cause corrosion of aluminum electrodes. This is a major cause of decreased reliability. Therefore, various improvements have been attempted in order to prevent defects caused by insufficient moisture resistance in semiconductor devices sealed with epoxy resin as described above, such as removing ionic impurities in the sealing material, Although it has been proposed to add additives that trap ionic substances, it is virtually impossible to completely and reliably remove or trap ionic substances even with these methods, and it is difficult to remove or trap ionic substances in the initial stage. It has the disadvantage of not being able to achieve its objectives. Conventionally, a silane coupling agent has been considered to be an essential component in order to improve the moisture resistance of a sealing material, and silane coupling agents for this epoxy resin composition for sealing semiconductor devices include epoxy silane,
Mercapto-based silanes, amine-based silanes, unsaturated hydrocarbon-based silanes, and the like are known. For example, epoxy silanes include 3-glycidoxypropyltrimethoxysilane, 2-(3,
4-Epoxycyclohexyl)ethyltrimethoxysilane is used, but the epoxy groups in these silanes have poor reactivity with phenol-curing epoxy resins, so burrs may occur during molding, and the amount added may be too low. There is a disadvantage that the electrical properties deteriorate as the silane increases, and 3-mercaptopropyltrimethoxysilane, for example, is used as a mercapto silane, but this has a strong odor and is problematic in practice; For example, N-(2-aminoethyl)-3
-Aminopropylmethyldimethoxysilane has been used, but compositions containing it have the disadvantage of extremely poor storage stability. On the other hand, as unsaturated hydrocarbon silanes, for example, vinyltriethoxysilane and 3-methacryloxypropyltrimethoxysilane are used, but since these do not have a functional group that reacts with the phenol-curable epoxy resin, they cannot be used as coupling agents. It is difficult to make full use of this function. The present inventors have conducted extensive research on silane coupling agents that do not have the disadvantages described above in epoxy resin compositions that are suitable for encapsulating electronic components. It was discovered that ((i) to (ii)) are extremely effective, and compositions containing them have unprecedented moisture resistance, leading to the completion of the present invention. That is, the present invention comprises (a) 100 parts by weight of a phenol-curable epoxy resin, (b) 100 to 500 parts by weight of an inorganic filler, and (c) a silicone compound represented by the following formula (i) or (ii). An epoxy resin composition containing 0.05 to 10 parts by weight of at least one selected material. (ii) R ² _x R ³ _y Y _z SiO〓〓〓〓 In the formula, R ¹ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, and R ² is the formula or

A group selected from [Formula] (where R ⁴ is a halogen atom or a group with 1 to 1 carbon atoms)
4 alkyl group, r is 0 or 1, Z is a hydrogen atom or glycidyl group), R ³ is an alkyl group having 1 to 4 carbon atoms, phenyl group, formula H ₂ N―CH ₂ CH ₂ CH ₂ ,―, NH ₂ ―CH ₂ CH ₂ CH ₂ ―
NH―CH ₂ CH ₂ CH ₂ ― or HS―CH ₂ CH ₂ CH ₂ ―
A group selected from the groups represented by, X is a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, Y is a hydroxyl group or a hydrolyzable group, l is 1, 2 or 3, m is 0, 1, 2 or 3, n is 0, 1 or 2, p is 1, 2 or 3, p+m≦5, x is 0.2-2.5, y is 0-2.5, x+y
is 0.2~2.5, z is 0.02~3, x+y+z is 0.2~
It is 4.0. The epoxy resin composition according to the present invention has excellent electrical and mechanical properties, and electronic components such as semiconductor devices sealed with this composition have less corrosion of aluminum wiring and excellent moisture resistance. . Therefore, when this composition is applied as an encapsulant for semiconductor devices such as ICs, LSIs, and transistors, it has excellent reliability, and since it has the above-mentioned properties, it is suitable for various paints and adhesives. For mold,
It can be widely applied to general molding, electrical insulation, laminates, etc. The composition according to the present invention will be explained in detail below. First, the phenol-curable curable epoxy resin as component (a) used in the present invention is a curable epoxy resin consisting of an epoxy resin having two or more epoxy groups in one molecule and a phenolic curing agent. The epoxy resin is not particularly limited in molecular structure, molecular weight, etc., and various conventionally known epoxy resins may be used as long as they can be cured with a phenolic curing agent as described below. These include, for example, epoxy resins synthesized from various novolak resins such as epichlorohydrin and bisphenol, alicyclic epoxy resins, and epoxy resins into which halogen atoms such as chlorine and bromine atoms are introduced. . In addition, when using the above-mentioned component (a), there is no problem in using a monoepoxy compound as appropriate. Examples of this monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, ethyl glycidyl ether, Examples include enyl glycidyl ether, allyl glycidyl ether, octylene oxide, and dodecene oxide. This component (a) is not necessarily 1 when used.
It is not limited to just the seeds, but a mixture of two or more types may be used. Furthermore, various conventionally known phenolic curing agents can be used, including those having two or more hydroxyl groups in one molecule, such as phenol novolac and cresol novolac. can. Furthermore, in the present invention, various curing accelerators such as imidazole or its derivatives, tertiary amine derivatives, phosphine derivatives,
There is no problem in using cycloamidine derivatives etc. in combination. Representative examples of the inorganic filler, which is component (b), include crystalline or amorphous silica, including Aerosil (trade name manufactured by Degutsusa) and Ultrasil (trade name manufactured by Degutsusa). Commercially available ultrafine powdered silica (usually having an average particle size of 1 to 30 μm) such as Celite (trade name manufactured by John Manville), Imsil (trade name manufactured by Illinois Minerals), etc.
Crystalline or amorphous quartz powder (usually 1-30μ
Examples include those having an average particle size of m). Generally, ultrafine powdered silica has excellent reinforcing properties, but its thickening significantly impedes fluidity, making it unsuitable for casting or molding. It is preferable to selectively use powders, which can impart excellent properties. Furthermore, fillers other than silica may also be used depending on the use and purpose of the composition of the present invention, such as talc, mica, clay, kaolin, calcium carbonate, alumina, zinc white, baryta, etc. , glass balloon, glass fiber, aluminum hydroxide, calcium hydroxide, asbestos, titanium oxide, iron oxide, silicon nitride, and the like. It goes without saying that these fillers are not limited to being used alone, but two or more types may be used in combination. The inorganic filler which is this component (B) is the component (A) above.
It is preferable to use it in a range of 100 to 500 parts by weight per 100 parts by weight. This is because when an amount exceeding 500 parts by weight is used, not only is dispersion difficult, but also satisfactory results cannot be obtained in terms of physical properties such as workability, low stress, and crack resistance. The silicone compound as component (c) is the most important component in the present invention, and has a remarkable effect on improving moisture resistance. ). In the above formula, R ₁ is an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, butyl group, or phenyl group, and R ² is the formula or

A group selected from [Formula], where R ⁴ is a halogen atom such as Cl, Br, I, or an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, butyl group, and r is 0 or 1, Z is a hydrogen atom or a glycidyl group, ^R3 is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, the formula H ₂ N―CH ₂ CH ₂ CH ₂ ,―, NH ₂ ―CH ₂ CH ₂ CH ₂ ―
NH―CH ₂ CH ₂ CH ₂ ― or HS―CH ₂ CH ₂ CH ₂ ―
A group selected from the groups represented by, X is Cl, Br,
A halogen atom such as I, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, or an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, Y is a hydroxyl group, an alkoxy group, an acyloxy group, a ketoxime group, an amino group, an aminoxy group,
Hydrolyzable group such as amide group, enoxy group, alkenyloxy group, l is 1, 2 or 3, m
is 0, 1, 2 or 3, n is 0, 1 or 2, p
is 1, 2 or 3, p+m≦5, x is 0.2 to 2.5,
y is 0 to 2.5, x+y is 0.2 to 2.5, z is 0.02 to 3,
x+y+z is assumed to be 0.2 to 4.0. Examples of such component (iii) include the compounds shown below. However, in the formula, Me represents a methyl group, Et represents an ethyl group, Bu represents a butyl group, and Ph represents a phenyl group. Group A; Group B; Group C; Group D; Among the above-mentioned compounds, the manufacturing method for those layered in group A is known (Japanese Patent Publication No. 41
-11097), softening agents for phenolic and coating resins, finishing agents for hard materials such as glass, glass cloth, silica or sand, molding compound laminates, end uses for shell molding, sand, It has been shown to be useful for bonding agent purposes and also as a curing agent and accelerator for epoxy resins. In addition, methods for synthesizing compounds belonging to group B are also known (Special Publications No. 55-
No. 36674), it is described that it is useful as an adhesion promoter for silicone rubber or as an intermediate for silicone alkyd resins. However, this known document does not describe at all that it is used to achieve the objects of the present invention. This (c) component is not necessarily 1 when used.
It is not limited to only one type, but two or more types may be used in combination. It is essential that the amount of the component (c) used is in the range of 0.05 to 10 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the component (a). The reason for this is that if it is less than 0.05 parts by weight, the effect of improving moisture resistance is not so great, whereas if it exceeds 10 parts by weight, the glass transition point of the cured product becomes low and oozing onto the surface of the cured product is observed. The method of adding this component (iii) is not particularly determined, and may be either an integral blend or adhesion to the surface of the inorganic filler. Furthermore, in the present invention, there is no problem in using together silicone compounds such as epoxy silanes, mercapto silanes, and amine silanes, aluminum compounds, alkyl titanate compounds, etc. that have been conventionally used in this type of composition. Various additives may be added to the composition according to the present invention depending on the use, purpose, etc., within a range that does not impede the purpose of the present invention. Examples include mold release agents such as mold release agents, fatty acids and waxes, coloring agents such as carbon black, flame retardants such as antimony compounds, and various flexibility imparting agents. Next, examples of the present invention will be given. However, all parts indicate parts by weight. Example 1 70 parts of cresol novolak type epoxy resin (manufactured by Ciba, trade name: ECN-1280), 30 parts of phenol novolak resin (manufactured by Gunei Chemical Co., Ltd., trade name: MP-120)
1 part, 2 parts of 2-undecylimidazole, 1 part of carnauba wax, 1 part of carbon black, 300 parts of silica powder and 1.5 parts of a silicone compound as shown in Table 1 below were heated to 60-100°C. After kneading with two mixing rolls for 3 to 6 minutes, the mixture was cooled and then ground.

[Table] Example 2 65 parts of phenol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name EPPN), 35 parts of phenol novolac resin (same as that used in Example 1)
1 part triphenylphosphine, 1 part carnauba wax, 1 part carbon black, silica powder
300 parts and formulas for quantities as shown in Table 2 below

The silicone compound represented by the formula was treated in the same manner as in Example 1 (kneading, cooling,
pulverized).

[Table] * Same example 3 as above For compositions 1 to 12 obtained in Examples 1 and 2 above, volume resistivity, bending strength, adhesion to Si chips or moldability (presence of burrs or exudation) ) was investigated as follows, and the results shown in Table 3 were obtained. (1) Volume resistivity: A disk with a diameter of 100 mm and a thickness of 2 mm was molded (molding temperature 175°C, molding time 2 minutes, molding pressure 70Kg/cm ² ), post-cured at 180°C for 4 hours, and then
The initial resistance value was calculated according to JISK6911, and then 200
The resistance value was calculated after being left for a certain period of time. (2) Bending strength: After molding a 100 x 10 x 4 (mm) bending rod (forming conditions; same as above) and post-curing at 180℃ for 4 hours, the initial value was measured according to JISK6911, and the bending strength was further pre-cured. 200 to Tusya Kutska (121℃, 2.2atm)
The bending strength was measured after being left for a period of time. (3) Adhesion with Si chips: After mounting a Si chip with a side of 4 mm and a thickness of 0.3 mm on a 14 PIN DIP frame, it was molded and sealed with the above composition (molding conditions; ), and post-cure was performed at 180°C for 4 hours. After that, the sealing resin was broken without destroying the Si chip, and the degree of bonding of the resin on the surface of the Si chip was examined and indicated by ○, △, and ×. ○...Very good △...Good ×...Poor (4) Formability; A disk with a diameter of 100 mm and a thickness of 2 mm was molded (molding conditions; same as above), and the gap between the molds during this molding was The presence or absence of burrs generated on the surface of the molded product and oozing of silicone compounds onto the surface of the molded product was investigated. ○...No burrs or oozes ×...There are burrs or oozes

【table】

[Table] Example 4 A Si chip with aluminum wiring (film thickness 1μ, line width 10μ) was mounted on a 14 PIN DIP frame, and then molded with the above compositions 1, 2, 3, 4, 6 and 7. It was sealed and post-cured at 180°C for 4 hours. Thereafter, it was left in a pressure vacuum cleaner and open defects in the aluminum wiring were measured, and the results shown in FIG. 1 were obtained. From the above results, Compositions 1 to 5 according to the present invention show little deterioration in volume resistivity and bending strength even after being left for 200 hours in the Pressure-Yakutsker test, while the control composition Composition 7 had a large deterioration in resistivity, and composition 7 had a large deterioration in bending strength.
It was confirmed that compositions 1 to 5 had excellent adhesion to Si chips. In addition, from Tables 2 and 3, products with a small amount of silicone compounds are pressurized
It can be seen that the change in physical properties after 200 hours is large, and conversely, those with a large change have poor moldability. Furthermore, as can be seen from Figure 1, Composition 1 has improved adhesion to Si chips compared to Compositions 6 and 7 (control products).
It can be seen that in samples 4 to 4 (products of the present invention), the corrosion time of the aluminum wiring was delayed.

[Brief explanation of the drawing]

Figure 1 shows the results of the present invention and control products.
It is a graph showing the results of an Al wiring corrosion test. Curves 1 to 4...Products of the present invention, Curves 6 to 7...Control products.

Claims (1)

[Scope of Claims] 1. Selected from (a) 100 parts by weight of a phenol-curable epoxy resin, (b) 100 to 500 parts by weight of an inorganic filler, and (c) a silicone compound represented by the following formula (i) or (ii). An epoxy resin composition consisting of 0.05 to 10 parts by weight of one type or a mixture of two or more types. (ii) R ² _x R ³ _y Y _z SiO〓〓〓〓 In the formula, R ¹ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, and R ² is the formula or a group selected from [Formula] (where R ⁴ is a halogen atom or a group having 1 to 1 carbon atoms)
4 alkyl group, r is 0 or 1, Z is a hydrogen atom or glycidyl group), R ³ is an alkyl group having 1 to 4 carbon atoms, phenyl group, formula H ₂ N―CH ₂ CH ₂ CH ₂ ,―, NH ₂ ―CH ₂ CH ₂ CH ₂ ―
NH―CH ₂ CH ₂ CH ₂ ― or HS―CH ₂ CH ₂ CH ₂ ―
A group selected from the groups represented by, X is a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, Y is a hydroxyl group or a hydrolyzable group, l is 1, 2 or 3, m is 0, 1, 2 or 3, n is 0, 1 or 2, p is 1, 2 or 3, p+m≦5, x is 0.2-2.5, y is 0-2.5, x+y
is 0.2~2.5, z is 0.02~3, x+y+z is 0.2~
It is 4.0.