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. 11, 2000
Filed:
Apr. 26, 1999
Takashi Kubara, Chikushino, JP;
Matsuo Masuda, Oita-ken, JP;
Tsuyoshi Tokiwa, Nakatsu, JP;
Hisahiro Tanaka, Fukuoka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a lead frame formed out of at least one metal selected from the group consisting of nickel and nickel alloys, copper and copper alloys and iron and iron alloys, the inner lead part is provided with a surface treatment layer of Ag or an alloy containing silver and the outer lead part is provided at least with a surface treatment layer of an alloy containing silver and tin of the body-centered cubic structure preferentially oriented in the (101) plane and/or the (211) plane. According to the above-mentioned structure, a semiconductor device that uses a lead frame for electronic parts which does not contain lead, one of the environmentally harmful pollutants, has good characteristics including solder wettability and bonding strength and is of low cost and a process for producing the device are provided.