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:
Mar. 23, 2004
Filed:
Jun. 14, 2000
Morio Gaku, Tokyo, JP;
Nobuyuki Ikeguchi, Tokyo, JP;
Yoshihiro Kato, Tokyo, JP;
Hiroki Aoto, Tokyo, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A method of making a high-density copper-clad multi-layered printed wiring board having a reliable through hole including providing a stacked assembly including three copper foil layers and at least two resin layers; providing an auxiliary material on a top surface of the stacked assembly and providing a backup sheet on a bottom surface of the stacked assembly to form an assembly; subjecting the top surface of the assembly to pulsed oscillation from a carbon dioxide laser to form at least one through-hole to produce a pulsed assembly; reducing the thickness of the front and reverse copper foil layers and simultaneously with reducing, removing copper foil burrs, to produce a cleaned assembly; and plating the cleaned assembly with copper to produce the high-density copper-clad multi-layered printed wiring board.