The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 08, 1994
Filed:
May. 10, 1993
Eiji Horikoshi, Isehara, JP;
Motoaki Tani, Atsugi, JP;
Isao Watanabe, Sagamihara, JP;
Katsuhide Natori, Yokohama, JP;
Takehiko Sato, Yokohama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A circuit board comprising a core material made from magnesium, a magnesium alloy, or a magnesium-based composite material, and an electric circuit formed on the core material. A process for producing the circuit board comprises the steps of (1) forming an electrodeposition-painted coating on such a core material, (2) forming a polyimide resin coating on the electrodeposition-painted coating, (3) forming a via hole extending through the resin coating to the underlying electrodeposition-painted coating, (4) etching and removing the electrodeposition-painted coating in the region exposed in the bottom of the via hole while masking the other region with the resin coating thereby extending the via hole to the core material, (5) forming a metal film on at least a free surface of the resin coating and an inner surface of the extended via hole, and (6) etching the metal film by using a photoresist mask to form a conductor layer having a predetermined pattern.