Matsushita Electric Works, Ltd.

Kenji Ogasawara

Keiko Kashihara

Yoshihiko Nakamura

Kiyotaka Komori

Yoshihisa Sugawa

Yasuo Tohrin

Akiyoshi Nozue

Shingo Yoshioka

Shigehiro Okada

Naoki Ito

Yoshinobu Marumoto

Ken-ichi Shinotani

Kohei Kotera

Tomoaki Iwami

Takuya Asano

Joji Sakakibara

An epoxy resin composition, which comprises, as an essential component, a phosphorus compound having an average of not less than 1.8 and less than 3 of phenolic hydroxy groups reactive with an epoxy resin and an average of not less than 0.8 of a phosphorus element in the molecule, an inorganic filler having an average particle diameter of not greater than 30 &mgr;m, a bifunctional epoxy resin having an average of not less than 1.8 and less than 2.6 of epoxy groups in the molecule and a hardener, wherein the bifunctional epoxy resin is contained at an amount of not less than 51% by mass relative to the whole epoxy resin, at least one of dicyandiamide and a polyfunctional phenol system compound having an average of not less than 3 of phenolic hydroxy groups in the molecule is used as the hardener and a ratio (a/c) of equivalent (a) of a phenolic hydroxy group of the phosphorus compound and equivalent (c) of an epoxy group of the bifunctional epoxy resin is not less than 0.3 and less than 0.75, and wherein aluminium hydroxide is used as the inorganic filler, an amount of the inorganic filler to be added is not less than 15 parts by mass and less than 100 parts by mass relative to 100 parts by mass of the resin solids constituent, and the content of a phosphorus element is not less than 0.8% by mass and less than 3.5% by mass relative to the whole resin solids constituent.

Epoxy resin composition, prepreg and multilayer printed-wiring board

Flame retardant resin composition

Process of impregnating a layer substrate having openings which is substantially defined by opposing two main surfaces with a resin composition in the form of liquid, and the process is characterized in that one of the main surfaces and the resin composition are kept in such a contact condition that the substrate is located on the resin composition. A prepreg and a laminate are also provided which are produced by the use of the substrate which has been prepared by the above process.

Process of impregnating substrate and impregnated substrate

A polyimide composition is prepared with a polyimide containing minute hollow spherules made of a glass of a hydroxyl group content and having less than 0.5 mg/m.sup.2. A multilayer substrate for printed-wiring is prepared with this polyimide composition. The substrate possesses a low dielectric constant, dielectric dissipation factor and thermal expansion coefficient.

Polyimide composition and prepreg and laminate thereof

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Kadoma, Japan

Kenji Ogasawara