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:
Nov. 22, 1994
Filed:
Sep. 16, 1992
Kazumi Ebihara, Satsuma, JP;
Fujitsu Limited, Kawasaki, JP;
Kyushu Fujitsu Electronics Ltd., Kagoshima, JP;
Abstract
A lead frame body having a chip mounting surface comprises first, second and third successive, laminated layers each having lower and upper surface, the lower main surface of the first layer defining a bottom main surface of the lead frame body and the upper main surface of the third layer defining the chip-mounting surface of the lead frame body. The first, second and third layers are formed of respective, different materials, the material of the second layer having a higher etching rate than the respective etching rate of the materials of the first and third layers. A plurality of spaced openings are formed in the first layer and which respectively correspond to and are in communication with a corresponding plurality of spaced hollow cavities in the second layer. The interior dimensions of the hollow cavities are greater than the corresponding interior dimensions of the respective openings, producing an annular lip of the material of the first layer at each opening which extends inwardly relatively to the respective hollow cavity.