JPH0249329B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a sealing resin composition having excellent moisture resistance, heat resistance, and mechanical properties. [Technical Background of the Invention and Problems thereof] Conventionally, methods have been used to resin-seal electronic components such as diodes, transistors, and integrated circuits using thermosetting resins. This resin sealing is economically advantageous compared to hermetic sealing methods using glass, metal, or ceramic, and is therefore widely put into practical use. Among thermosetting resin compositions, epoxy resin compositions are most commonly used as sealing resin compositions in terms of reliability and cost.
For the epoxy resin, a curing agent such as acid anhydride, aromatic amino, novolac type phenol resin, etc. is used. Among these, epoxy resin compositions using novolak type phenolic resin as a curing agent have better moldability and better moldability than epoxy resin compositions using other curing agents.
It is widely used as a semiconductor encapsulation material because it has excellent moisture resistance, is nontoxic, and is inexpensive. However, epoxy resin compositions using novolak type phenolic resin as a curing agent have a drawback of being inferior in reliability with respect to moisture resistance and heat resistance, which is associated with the increasing density of electronic parts. When a molded product using such a resin composition is subjected to a hot/cold cycle test, bonding wire opens, resin cracks, and pellet cracks occur, making it unable to function as an electronic component, and when a moisture resistance test is performed, the same problem occurs as above. A phenomenon occurs that prevents the device from functioning properly. For these reasons, the development of a sealing resin composition with excellent moisture resistance, heat resistance, and mechanical properties has been awaited. [Object of the Invention] The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a sealing resin composition that is moisture resistant, heat resistant, and has excellent mechanical properties. It is something. [Summary of the Invention] As a result of extensive research to achieve the above object, the present inventors have found that the following sealing resin composition has superior moisture resistance and heat resistance compared to conventional ones, It has been found that it has high mechanical properties and is suitable for use in sealing resin compositions. That is, the present invention provides (A) an epoxy resin (B) a general formula (In the formula, R is a hydrogen atom or an alkyl group, m is 1
A polycondensate of phenol and aralkyl ether represented by (representing an integer greater than or equal to). (C) A sealing resin composition, which contains an inorganic filler as an essential component, contains 25 to 90% by weight of the inorganic filler based on the resin composition, and does not contain a curing accelerator. . The epoxy resin (A) used in the present invention is not particularly limited in terms of molecular structure, molecular weight, etc., and includes a wide range of commonly used epoxy resins, as long as the epoxy resin is a compound having at least two epoxy resins in its molecule. Can be done. Examples include aromatic resins such as bisphenol, alicyclic resins such as cyclohexane derivatives, and epoxy novolac resins represented by the following general formula. (In the formula, R ¹ is a hydrogen atom, a halogen atom, or an alkyl group, R ² is a hydrogen atom or an alkyl group, n
represents an integer of 1 or more) These epoxy resins can be used alone or in combination of two or more. Examples of the polycondensate of phenol and aracyl ether (B) used in the present invention include Zyrock 225 developed by Albright-Wilson (UK). The amount of the polycondensate of phenol and aralkyl ether to be used is based on the epoxy group (a) of the epoxy resin (A).
and (B) the phenolic hydroxyl group (b) of the polycondensate of phenol and aralkyl ether, the molar ratio a/b is
It is preferably within the range of 0.1 to 10. If the molar ratio is less than 0.1 or more than 10, the moisture resistance, molding workability, and electrical properties of the cured product will deteriorate, and either case is unfavorable. Therefore, the above range is preferable. Inorganic fillers (C) used in the present invention include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay,
Examples include asbestos, mica, red iron oxide, glass fiber, and carbon fiber, with silica powder and alumina being particularly preferred. (C) The blending ratio of the inorganic filler is
It needs to be 25 to 90% by weight of the resin composition. If the inorganic filler is less than 25% by weight, moisture resistance,
It has no effect on heat resistance, mechanical properties, or moldability, and if it exceeds 90% by weight, it becomes bulky and has poor moldability, making it unsuitable for practical use. The sealing resin composition of the present invention mainly contains an epoxy resin, a polycondensate of phenol and aralkyl ether, and an inorganic filler. Mold release agents such as metal salts, acid amides, esters or paraffins, flame retardants such as chlorinated paraffins, bromotoluene, hexabromobenzene, and antimony trioxide, colorants such as carbon black and red iron, and silane coupling agents. There is no problem in adding and blending etc. as appropriate. In the present invention, component (B) is a curing agent, but no curing accelerator such as imidazole, amine, or organic phosphine compound is used. A general method for preparing the sealing resin composition of the present invention as a molding material is to use an epoxy resin, a polycondensate of phenol and aralkyl ether, an inorganic filler, or other materials selected at a predetermined composition ratio. After sufficiently uniformly mixing the raw material components using a mixer or the like, the mixture is further melt-mixed using hot rolls or mixed using a kneader, etc., and then cooled to solidify and pulverized to an appropriate size to obtain a molding material. Can be done. When the encapsulating resin composition according to the present invention is applied to encapsulating, coating, insulating, etc. electronic components and electrical components, excellent characteristics and reliability can be imparted. [Effects of the Invention] The encapsulating resin composition of the present invention has good moisture resistance,
Since it is a sealing resin composition that has high heat resistance, excellent mechanical properties, and good moldability, sufficient reliability can be obtained when it is used for sealing electronic and electrical parts. [Examples of the Invention] The present invention will be specifically explained by Examples, but the present invention is not limited to the following Examples. In the following Examples, [%] means [% by weight]. Example 1 15% of cresol novolac epoxy resin (epoxy equivalent 215), 15% of Zyloc 225 (trade name of Albright-Wilson Co.) and 70% of silica powder were mixed at room temperature, kneaded at 90 to 95°C, and cooled. It was crushed to obtain a molding material. The obtained molding material was made into a tablet, injected into a mold that had been preheated and heated to 170°C by transfer molding, and cured to obtain a molded product. Various properties of this molded article were measured and the results are shown in Table 1. Example 2 18% cresol novolac epoxy resin (epoxy equivalent 215), 12% Zyloc 225 (trade name Albright Wilson) and 70% silica powder were treated in the same manner as in Example 1 to obtain a molding material, and then molded. A molded article was obtained using the material. Various properties of the obtained molded article were measured and the results are shown in Table 1. Comparative Example 1 A molding material was obtained by treating 20% of cresol novolak epoxy resin (epoxy equivalent: 215), 10% of novolak type phenol resin (phenol equivalent: 107), and 70% of silica powder in the same manner as in Example 1. A molded product was obtained using Various properties of the obtained molded product were measured and the results are shown in Table 1.

【table】

【table】

[Table] It can be seen that the Examples are also superior to the Comparative Examples in terms of moisture resistance, heat resistance, and crack occurrence.

Claims (1)

[Claims] 1 (A) Epoxy resin (B) General formula (In the formula, R is a hydrogen atom or an alkyl group, m is 1
A polycondensate of phenol and aralkyl ether (representing an integer of A sealing resin composition characterized in that it does not contain an accelerator. 2. A patent characterized in that the molar ratio (a/b) between the epoxy group (a) of the epoxy resin and the phenolic hydroxyl group (b) of the polycondensate of phenol and aralkyl ether is within the range of 0.1 to 10. The sealing resin composition according to claim 1.