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. 08, 1985
Filed:
Mar. 08, 1983
Robert Newman, San Jose, CA (US);
Fred Johnson, Sunnyvale, CA (US);
Monolithic Memories, Inc., Santa Clara, CA (US);
Abstract
A semiconductor die attach adhesive is provided which is formed of a plurality of spacers formed in a suspension of silver filled glass. In one embodiment of this invention, the spacers are spheres. The spacers utilized in one embodiment of this invention have a melting temperature below the temperature at which the solvents are evaporated from the die attach adhesive. In this manner, as the solvents are driven from the silver filled glass during the die attach operation, thus causing the volume of the silver filled glass to decrease, the spacers utilized in this invention partially melt, thus decreasing their thickness. This decreased thickness of the spacers decreases the separation between the die and the substrate, thus preventing the formation of voids within the die attach adhesive. In one embodiment, the spacers are formed of a lead/tin alloy. In another embodiment of this invention, the spacers are formed of a lead/tin/bismuth alloy, and in yet another embodiment of this invention the spacers are formed of lead/tin/bismuth eutectic.