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:
Jun. 22, 1993
Filed:
Feb. 26, 1991
Applicant:
Inventors:
Shiro Kobayashi, Hitachi, JP;
Narutoshi Kazama, Hitachi, JP;
Masahiko Itoh, Hitachioota, JP;
Noriyuki Ohnaka, Katsuta, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257676 ; 257677 ; 361421 ; 174 522 ;
Abstract
A lead frame of a plastic encapsulated type semiconductor device is provided with a coating film which has a solderability higher than a solderability of a basic metal of the lead frame, and the coating film has a corrosion potential higher than a corrosion potential of the basic metal. The coating film protects the basic metal from corrosion caused by the plastic encapsulated member. The coating film of the lead frame made of a Fe-Ni alloy is an alloy comprising metal selected from Mo, W, Au, Cr, Cu, metals of the platinum group and a metal selected from Fe, Co, and Ni.