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:
Jul. 17, 1990
Filed:
Feb. 22, 1988
Makoto Kitano, Ibaraki, JP;
Sueo Kawai, Ibaraki, JP;
Asao Nishimura, Ushiku, JP;
Hideo Miura, Ibaraki, JP;
Akihiro Yaguchi, Ibaraki, JP;
Chikako Kitabayashi, Ibaraki, JP;
Ichio Shimizu, Gunma, JP;
Toshio Hatsuda, Ibaraki, JP;
Toshinori Ozaki, Ibaraki, JP;
Toshio Hattori, Ushiku, JP;
Souji Sakata, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A lead frame and a semiconductor device wherein a through hole is formed in the center of a semiconductor chip-mounting surface of a chip pad at the center of the lead frame, the through hole being tapered or being one which corresponds to a surface area that is greater on the surface of the chip-mounting surface of the chip pad than on the surface of the side opposite to the chip-mounting surface thereof. This prevents the occurrence of cracks in the sealing plastic portion in the step of reflow soldering of the lead frame to the substrate.