JPH0234182B2 - DENSHIBUHINFUSHOSEIKEIZAIRYO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a molding material for sealing electronic components, and its purpose is to prevent a decrease in surface resistivity during humidification, eliminate surface leakage current when voltage is applied, and improve the moisture resistance of electronic components. The goal is to improve. In recent years, various electronic components have been encapsulated with plastic in order to reduce costs and improve productivity. These electronic components include, for example, transistors. Casting, compression molding, injection molding, transfer molding, etc. are used as sealing methods with these plastics, and injection and transfer molding methods, which are superior in mass production and workability, are often used to improve productivity. has been done. Generally, these electronic components are small and are molded in a large number of molds, such as 50 to 200 molds. For this reason, thermosetting resin molding materials such as silicone resin molding materials, epoxy resin molding materials, and unsaturated polyester resin molding materials are used as sealing materials to satisfy multi-cavity molding. The material has the disadvantage of low mechanical strength and weak adhesion to metals, and epoxy resin molding materials have poor flowability and storage stability, so they must be stored in the freezer and left at room temperature during molding operations. However, unsaturated polyester resin molding materials have high mechanical strength, good adhesion to metals, and have good flowability, long shelf life, and excellent moldability. However, it is currently hardly used as a material for encapsulating electronic components because of its poor moisture resistance. As a result of various studies on the sealing performance of electronic components during humidification, the present inventors were able to significantly improve the moisture resistance by adding a specific organic silicon compound to the unsaturated polyester resin molding material. This makes it possible to apply unsaturated polyester resin molding materials to the field of encapsulating electronic components, which was previously impossible. Although the amount of the specific organosilicon compound used in the present invention is not particularly limited, it is preferably 0.01 to 3% by weight.
(hereinafter simply referred to as %) is desirable. The present invention has been made in view of the above points, and has high mechanical strength, good adhesion to metal,
It was possible to obtain a molding material for encapsulating electronic components that has good flowability, good storage stability, good moldability, and excellent moisture resistance. The present invention will be explained in detail below. The molding material for encapsulating electronic components according to the present invention contains isophthalic acid. Orthophthalic acid. Phthalic anhydride. Succinic acid. Adipic acid. Sebacic acid. Endomethylenetetrahydrophthalic anhydride. Saturated dibasic acids such as chlordic acid and ethylene glycol. Dipropylene glycol. 1.3 Butanediol. Hydrogenated bisphenol. Neopentyl glycol. Isobentel glycol. 1.6 Polyhydric alcohols such as hexanediol and maleic acid. maleic anhydride.
Fumaric acid. An unsaturated polyester resin obtained by reacting an unsaturated dibasic acid such as itaconic acid with styrene, t-butylstyrene. Chlorostyrene. Divinylbenzene. Diaryl phthalate.
Vinyl toluene. A monomer or its prepolymer having an unsaturated group that reacts with unsaturated polyester resins such as acrylic esters is added as a crosslinking agent, and furthermore, glass fiber, metal whisker, carbon fiber, Kevlar fiber, polyester fiber, polyamide fiber, pulp, asbestos, calcium silicate,
Adding fillers such as barite, mica, clay, sericite, alumina, molybdenum sulfide, calcium carbonate, silicic acid, basic magnesium carbonate, magnesium carbonate, calcium hydroxide, aluminum hydroxide, antimony trioxide, talc, titanium oxide, etc.
Furthermore, unsaturated polyester resin molding is made of mold release agents such as zinc stearate and wax, coloring agents such as carbon black and iron oxide, curing initiators such as t-butyl peroxybenzoate and benzoyl peroxide, and additives such as coupling agents. It is made by adding an organic silicon compound represented by formula 1 to the material. Although the amount of the organosilicon compound is not particularly limited, it is preferably 0.01 to 3%. That is, if the amount of the organic silicon compound is less than 0.01%, the effect of improving moisture resistance tends to decrease, and if it exceeds 3%, the adhesion to metal tends to decrease. (In formula 1, R represents a hydrogen group, a methyl group, or a phenyl group, but it is preferable that a part of R is further modified with a hydroxyl group, an amino group, or an epoxy group.
That is, this is because the effect of improving moisture resistance tends to be greater. ) As mentioned above, the present invention is characterized by adding a specific organic silicon compound to an unsaturated polyester resin molding material consisting of an unsaturated polyester resin, a crosslinking agent, a filler, and an additive. The curing reaction is triggered by separation of the curing initiator, and unsaturated groups participate in crosslinking. Therefore, it is more stable at room temperature than curing by addition condensation reaction such as epoxy resin molding materials, and has good storage stability. In addition, since the flowability during molding can be improved by a crosslinking agent, it is suitable for molding multiple electronic parts by transfer molding and injection molding, and can also be applied to cast molding and compression molding. Organosilicon compounds, for example, those in which the terminal or side chain R in the formula [1] above represents a methyl group, a phenyl group, and some of these R are replaced with a hydrogen group or a hydroxyl group, or an amino group or an epoxy group. Specifically, in hydrogen group-modified silicones, silanol-modified silicones, amino-modified silicones, epoxy-modified silicones, etc., hydrogen groups, or reactive groups such as hydroxyl groups, amino groups, and epoxy groups are unsaturated. Moisture resistance can be improved by reacting with the vinyl groups of polyester resin. Next, the present invention will be specifically explained using Examples and Comparative Examples. Examples 1 to 5 Unsaturated polyester resin obtained by reacting 1 mol of isophthalic acid, 1 mol of fumaric acid, and 2.2 mol of propylene glycol was blended, mixed, and kneaded according to the first mixing bale to encapsulate electronic components. A molding material for stopping was obtained.

[Table] The molding materials obtained in Examples 1 and 2 and Examples 4 and 5 as described above were molded using a transfer molding material at a mold temperature of 145°C, a molding pressure of 40 Kg/cm ² , and a curing time of 2 minutes. A molded product was molded under the conditions of Example 3.
The molding material obtained is cast and molded at 150℃.
The molded product was obtained by curing for 30 minutes. Comparative Example A molded article was obtained from Example 1 with the organosilicon compound removed and treated in the same manner as in Example 1. The results of the surface leakage current test and surface water repellency test of the molded products of Examples 1 to 5 and Comparative Examples are as shown in Table 2. The surface leakage current of
It was also confirmed that the molding material for encapsulating electronic components according to the present invention has good surface water repellency.

【table】

Claims (1)

[Claims] 1. Unsaturated polyester resin, crosslinking agent, filler,
A molding material for encapsulating electronic components, which is made by adding an organic silicon compound represented by formula [1] to an unsaturated polyester resin molding material comprising an additive. (In formula [1], R represents a methyl group or a phenyl group.) 2. Electronic component encapsulation according to claim 1, characterized in that the amount of the organic silicon compound added is 0.01 to 3% by weight. molding material. 3. Claim No. 3, characterized in that the terminal R or side chain R of the organosilicon compound represented by formula [1] is partially modified with a hydroxyl group, an amino group, or an epoxy group. The molding material for encapsulating electronic components according to item 1 or 2.