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:
Oct. 20, 2020
Filed:
Mar. 20, 2020
Ohkuchi Materials Co., Ltd., Isa, Kagoshima, JP;
OHKUCHI MATERIALS CO., LTD., Kagoshima, JP;
Abstract
A lead frame includes a lead frame substrate made of a copper-based material, plating layers composed of nickel, palladium and gold layers laminated in this order on top faces and bottom faces of the lead frame substrate, and a roughened silver plating layer having acicular projections, provided as an outermost plating layer and covering faces of the lead frame substrate that form concavities or a through hole between the top faces and the bottom faces of the lead frame substrate. The roughened silver plating layer has a crystal structure in which the crystal direction <101> occupies a largest proportion among the crystal directions <001>, <111> and <101>. The lead frame can be manufactured with improved productivity owing to reduction in cost and operation time, and achieves remarkably high adhesion to sealing resin while keeping the total thickness of plating layers including the silver plating layer to be thin.