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. 09, 1990
Filed:
Feb. 21, 1990
Degussa Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
A solder paste for fastening semiconductors onto ceramic bases in a temperature range below 380.degree. C., consisting essentially of (1) 75 to 90% by weight of a mixture of silver powder and a low-melting glass powder with the weight ratio of silver to glass being between 2:1 and 9:1 and (2) 10 to 25% by weight of an organic solvent which contains 1 to 10% by weight of a thermally readily decomposable resin, the glass powder consisting essentially of 75 to 85% by weight lead oxide, 8 to 15% by weight boron oxide, 0.5 to 10% by weight silver (I) oxide 0.5 to 10% by weight bismuth (III) oxide, 0 to 5% by weight silicon dioxide, 0 to 2% by weight aluminum oxide 0 to 2% by weight tin oxide, 0 to 2% by weight zinc oxide, the glass powder having a glass transition temperature (Tg) of 250.degree. to 300.degree. C.