Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Toyoki Ito

Akishi Nakaso

Akira Shimizu

Hiroshi Shimizu

Fumio Inoue

Naoyuki Urasaki

Yoshiyuki Tsuru

Shigeharu Arike

Kazuhito Kobayashi

Daisuke Fujimoto

Nobuyuki Ogawa

Kouichi Tsuyama

Kazuhisa Otsuka

Yasuo Inoue

Masaharu Matsuura

Norio Okano

Tomoaki Yamashita

A method of treating the surface of copper is provided to ensure adhesive strength between the surface of copper and an insulating layer without forming irregularities exceeding 1 &#x3bc;m on the surface of copper and to improve insulation reliability between wirings. A copper whose surface is treated by the above surface treating method is also provided. The method of treating the surface of copper comprises the surface of copper comprising the steps of: forming a metal nobler than copper discretely on the surface of copper; and subsequently oxidizing the surface of copper by using an alkaline solution containing an oxidant.

Method of treating the surface of copper and copper

A multilayer printed circuit board small in interlayer thickness, capable of fine wiring, minimized in IVH and BVH diameters, high in strength and also excellent in wire bonding workability can be produced by a process comprising the steps of coating a thermosetting resin varnish compounded with electrically insulating whiskers on a roughened side of a copper foil, semi-curing the resin by heating to form a thermosetting resin layer, integrally laminating it on an interlayer board in which plated through-holes and conductor circudits have been formed, and roughening the cured thermosetting resin layer on the via hole wall surfaces with a roughening agent.

Process for producing multilayer printed circuit board for wire bonding

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Chikusei, Japan

Toyoki Ito