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. 21, 2000
Filed:
Jun. 25, 1999
Frans Peter Lautzenhiser, Noblesville, IN (US);
Joel Franklin Downey, Kokomo, IN (US);
Marion Edmond Ellis, Kokomo, IN (US);
Delphi Technologies, Inc., Troy, MI (US);
Abstract
16 A thick-film circuit (10) includes an electrically conductive substrate (12), such as stainless steel, and a first layer of a gold-rich conductor (15) applied directly thereon. The gold layer is fired in a non-oxidizing atmosphere, such as nitrogen, to ensure a solid mechanical and electrical connection between the gold and the substrate. A next layer of a silver composition (20) containing a first proportion of silver to a conductive metal is directly applied to the gold layer (15). Preferably, the composition (20) includes palladium in equal parts with the silver to achieve a secure mechanical and electrical contact with the gold layer with a minimum resistivity. A silver-rich layer (23) is then applied directly onto the intermediate layer. This silver-rich layer (23) is a composition of silver and the conductive metal in a second proportion greater than the first proportion. In one embodiment, this second proportion is three parts silver to one part palladium by weight. The thick-film stack-up (10) provides a minimum resistance conductive path between electrical components mounted on the silver-rich layer (23) and the conductive substrate (12).