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. 28, 2009
Filed:
Oct. 26, 2006
Shigeru Sato, Inagi, JP;
Jiro Takeda, Machida, JP;
Atsushi Kayama, Sagamihara, JP;
SO Suzuki, Hachioji, JP;
Lionel Beneteau, Kolsas, NO;
Shigeru Sato, Inagi, JP;
Jiro Takeda, Machida, JP;
Atsushi Kayama, Sagamihara, JP;
So Suzuki, Hachioji, JP;
Lionel Beneteau, Kolsas, NO;
Schlumberger Technology Corporation, Sugar Land, TX (US);
Abstract
The principles described herein relate to methods for soldering electrode terminals, pins or lead-frames of commercial electric components for high temperature reliability. In one embodiment, prior to soldering the electric components, a pre-plated solder layer is removed from the lead frame or pins, and nickel and/or gold films are formed with electroless plating. The removal of the pre-plated solder layer avoids excess pre-plated Sn with high-Pb solder that lowers the melting point to between 180° C. and 220° C. and weakens solder joints. The nickel layer formed with an electroless plating acts as a barrier to the interdiffusion of tin from solder with copper of the lead frame material, which may otherwise occur at high temperatures. Interdiffusion forms an intermetallic compound layer of copper and tin and degrades solder joint strength. The novel soldering processes improve high temperature reliability of solder joints and extend electronics life-time.