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:
Aug. 10, 1999
Filed:
Oct. 15, 1996
Sony Corporation, Tokyo, JP;
Abstract
A method of manufacturing a lead frame comprises the steps of preparing a three-layered material comprising a metal base, an etching stopper layer made of a metal material different from that of the metal layer formed on a first surface of the metal base and a chromium layer formed on the etching stopper layer, forming a resist layer having a negative pattern relative to an inner lead to be formed on the chromium layer of the three-layered material, forming an inner lead by plating copper by using the resist layer as a mask, forming an outer lead on the metal base, removing a back of a region in which an inner lead of the metal base is formed by etching, removing the etching stopper layer, and removing the chromium layer.