Tomoegawa Paper Co., Inc.

Fumiyoshi Yamanashi

Takeshi Nishigaya

Takeshi Hashimoto

Yukinori Sakumoto

Masaharu Kobayashi

Katsuji Nakaba

Osamu Oka

Akira Tezuka

The present invention provide a novel polyimide which is soluble in organic solvents and excels in heat resistance, and to a process for producing the polyimide. The polyimide of the present invention comprises a repeating unit represented by the formula (1) and having a number average molecular weight of from 4,000 to 200,000.

Adhesive tape for electronic parts and liquid adhesive

This invention provide an adhesive tape and a liquid adhesive for electronic parts having sufficient thermal resistance and reliability. The adhesive tape comprises an adhesive layer composed of at least a polyimide comprising the repeating units represented by the formulas (1) and (2), provided on surface of a heat resistance film or a release film: ##STR1## wherein X is --SO.sub.2 -- and/or --C(.dbd.O)--OCH.sub.2 CH.sub.2 O--C(.dbd.O)--, Ar is a divalent group containing aromatic rings, and R is an alkylene group having 1 to 10 carbon atoms or --CH.sub.2 OC.sub.6 H.sub.4 --, and n means an integer of 1 to 20.

The present invention provide a novel polyimide which is soluble in organic solvents and excels in heat resistance, and to a process for producing the polyimide. The polyimide of the present invention comprises a repeating unit represented by the formula (1) and having a number average molecular weight of from 4,000 to 200,000. ##STR1## wherein X is --SO.sub.2 -- or --C(.dbd.O)--OCH.sub.2 CH.sub.2 O--C(.dbd.O)--, and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.

This invention provide an adhesive tape by which adhesion to a metal spreader is not required and a cutting process is not necessary. The adhesive tape comprises an adhesive layer provided on at least one surface of metal sheet, said adhesive layer being semi-cured into a B-stage and comprised of: (a) a piperazinylethylaminocarbonyl-containing butadiene-acrylonitrile copolymer of the formula (I): ##STR1## wherein, k, m, and n are molar ratios and taking n as l, k is a number of 3-175, and m is a number of 0.3 to 93; and (b) a compound having at least two maleimide groups, the ratio of component (b) based on 100 parts by weight of component (a) being in a range of 10 to 900 parts by weight, and said adhesive layer being composed of at least two semi-cured layers having each a different status of semi-cure.

Adhesive tapes which can be adhered and cured at a relatively low temperature, keeps enough electric insulation in case of adhering to the leadframe of semiconductor devices. The adhesive tape comprises a releasing film and an adhesive layer provided on a surface of said releasing film, said adhesive layer being semi-cured into a B-stage and composed of:

This invention is to provide a liquid adhesive of the present invention can be adhered and cured at a relatively low temperature and have sufficient heat resistance and reliability, etc., and an adhesive tape using the same. The liquid adhesive of this invention is obtainable by dissolving (a) a piperazinylethylaminocarbonyl-containing butadiene-acrylonitrile copolymer having a weight average molecular weight of 10,000-200,000, an acrylonitrile content of 5-50% by weight, and an amino equivalent of 500-10,000, represented by the following formula (I): ##STR1## wherein, k, m, and n are molar ratios and taking n as 1, k is a number of 3-175, and m is a number of 0.3 to 93; and (b) a compound having at least two maleimide groups, the ratio of component (b) based on 100 parts by weight of component (a) being in the range of 10 to 900 parts by weight. This is applied to one or both surfaces of a heat resistant film or one surface of a release film to form an adhesive layer, thereby obtaining an adhesive tape for electronic parts.

This invention is to provide a liquid adhesive can be adhered and cured at a relatively low temperature and have sufficient heat resistance and reliability, etc., and an adhesive tape using the same. The liquid adhesive of this invention is obtainable by dissolving

The piperazinylethylaminocarbonyl-containing butadiene-acrylonitrile copolymer of this invention is a novel substance useful as an adhesive component for adhesive tapes, which tapes are used in the interior of a resin-sealed type semiconductor device. The copolymer has a weight average molecular weight of 10,000-200,000, and is represented by the following general formula (I) and obtained by condensing a carboxyl-containing butadiene-acrylonitrile copolymer having a weight average molecular weight of 10,000-200,000 with N-aminoethylpiperazine in the presence of a phosphite and a pyridine derivative to undergo the amidation. ##STR1## wherein k, m, and n indicate molar proportions, where n is taken as 1, k is a number in the range of 3-175, and m is a number in the range of 0.3-93.

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Shizuoka, Japan

Fumiyoshi Yamanashi