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. 20, 1991
Filed:
May. 02, 1990
Applicant:
Inventors:
Makoto Kitano, Tsuchiura, JP;
Asao Nishimura, Ushiku, JP;
Akihiro Yaguchi, Ibaraki, JP;
Sueo Kawai, Ibaraki, JP;
Akio Hoshi, Isesaki, JP;
Ichio Shimizu, Gunma, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
357 70 ; 357 67 ; 357 71 ;
Abstract
A lead frame having a plurality of inner leads and outer leads, said outer leads being subjected to surface treatment for improving solder wettability at an end portion and to sruface treatment for suppressing solder wettability at least at a portion neighboring to the end portion, or said outer leads being bent 4 times or more, is effective for improving thermal fatigue life and reliability when applied to a semi-conductor device.