Sumitomo Metal Industries, Inc.

Sumikin Chemical Co., Ltd.

Bridgestone Corporation

Haruyuki Kano

Yoshihisa Sone

Kazuhiro Minagawa

Shoichi Kojima

Tasuku Saito

Hiroaki Wada

Sugio Otani

Tadaaki Miyazaki

Kenji Kageyama

Toshiaki Mabuchi

Tasuo Kurachi

Kazunari Nawa

Michio Tsuyuguchi

Hiroichi Kouyama

Kouichi Yoshimura

A phenolic resin obtained by reacting a phenol with an aromatic aldehyde and a xylylene compound represented by the formula

Phenolic resin

A process for the preparation of a silicon carbide sintered body of high purity which has a content of 1 ppm or less of each atom harmful to the manufacture of semiconductor equipment including the step of shaping a silicon carbide powder, calcining the shaped body in a non-oxidizing atmosphere to form a porous body, and subjecting the porous body to reaction sintering while being impregnated with molten metallic silicon. The starting silicon carbide powder also has a content of 1 ppm or less of each harmful atom and it has a free carbon content of not greater than 20% by weight and an average particle diameter of 0.5-20 .mu.m. Such silicon carbide powder can be prepared from a carbon- and silicon-containing starting mixture including at least one liquid hydrolyzable silicon compound and at least one carbonaceous material selected from polymerizable or cross-linkable organic compounds prepared in the presence of a catalyst which is substantially free from harmful atoms by solidifying the starting mixture and heating it so as to react and form silicon carbide.

Process for preparing a silicon carbide sintered body for use in

A heat-resistant, electrical insulating layer which is suitable for use as an insulating substrate in printed circuit boards and as an insulating film for semiconductor devices and which surpasses a polyimide-based insulating layer with respect to heat resisting properties, dielectric properties, and water absorption. The insulating layer comprises a polycondensed fused polycyclic, polynuclear aromatic resin prepared by a polycondensation reaction of a starting material with a crosslinking agent in the presence of an acid catalyst. The starting material is selected from the group consisting of fused polycyclic aromatic hydrocarbons which may have a hydroxyl group as a ring substituent and mixtures of a fused polycyclic aromatic hydrocarbon and a monocyclic aromatic hydrocarbon both of which may have a hydroxyl group as a ring substituent. The crosslinking agent is an aromatic compound having at least two hydroxymethyl or halomethyl groups as ring substituents.

Heat-resistant electrical insulating layer

A process for the preparation of a beta-silicon carbide powder of high purity which is suitable for use in the manufacture of semiconductor equipment and which has a content of 1 ppm or less of each atom harmful to the manufacture of semiconductor devices. The process comprises preparing a carbon- and silicon-containing starting mixture comprising (a) at least one siliceous material selected from liquid silicon compounds and solid siliceous substances derived from a hydrolyzable silicon compound, and (b) at least one carbonaceous material selected from polymerizable or cross-linkable organic compounds prepared in the presence of a catalyst which is substantially free from atoms harmful to the manufacture of semiconductor devices. The starting mixture comprises at least one liquid substance used as component (a) or (b). The starting mixture is then solidified by heating and/or by use of a catalyst or a curing agent. The resulting solid body is optionally heat treated in a non-oxidizing atmosphere at a temperature in the range of from 500.degree. C. to 1300.degree. C. for a period sufficient to remove volatiles. The cured and optionally heat-treated body is calcined in a non-oxidizing atmosphere under conditions sufficient to give beta-silicon carbide powder.

Process for preparing silicon carbide powder for use in semiconductor

A condensed polycyclic, polynuclear aromatic thermosetting resin with improved moldability which is prevented from forming a cloud on a mold during molding is disclosed. The resin is a prepolymer derived by condensation polymerization of a condensed polycyclic aromatic compound or a mixture thereof with a monocyclic aromatic compounds and an aromatic compound having at least two hydroxymethyl groups as a crosslinking agent in the presence of an acid catalyst. The resin has a flow temperature of not higher than 150.degree. C. The acid catalyst is water-insoluble or when it is water-soluble the resin has an insolubilized acid ratio of at least 50%. The resin is useful in the manufacture of thermoset molded articles having good heat resistance and good mechanical and electrical properties. It can be blended with a filler and/or reinforcing agent to form a molding compound.

Condensed polycyclic, polynuclear aromatic thermosetting resin having

Growing community of inventors

Ibaraki-ken, Japan

Haruyuki Kano