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:
Dec. 26, 1989
Filed:
Mar. 31, 1989
Meiko Electronics Co., Ltd., Kanagawa, JP;
Toagosei Chemical Industry Co., Ltd., Tokyo, JP;
Abstract
A method suited for producing a conductor circuit board having a high-density, fine circuit pattern. Conductor circuits and dummy circuits are formed on the surface of a planar, electrically conductive substrate, and after removing a resist mask, unnecessary dummy circuits are removed. A thin metal film is formed over the surface of the conductive substrate and the surfaces of the conductor circuits and remaining dummy circuits. An insulating substrate is superposed on the surface of the conductive substrate on which the thin metal film is formed, and the two substrates are pressure-bonded together with heat applied thereto. Subsequently, only the conductive substrate is removed, and exposed portions of the thin metal film are removed by etching. In the case of producing a conductor circuit board with a through hole, a through hole is formed after the step of separating the conductive substrate, and then through-hole plating is carried out, followed by the removal of exposed portions of the thin metal film by etching.