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:
Jan. 03, 1978
Filed:
Nov. 03, 1976
Franz Kummer, Rodenbach, DT;
Gerhard Mai, Bruchkobel, DT;
Rolf Ruthardt, Hanau, DT;
Horst Thiede, Rossdorf, DT;
W. C. Heraeus GmbH, Hanau, DT;
Abstract
To improve the bonding layer for connecting wires to semiconductor chips with contact fingers, or contact strips, on a substrate carrier, the bonding layer is formed as spongy, microporous structure, applied to discrete positions of the contact strips by screen printing, and secured to the metallic connecting strip by a diffusion zone. Preferably, the bonding layer comprises a metal of gold, palladium, silver, aluminum and copper, or an alloy of at least two of these metals, or a base alloy of one of these metals, for example gold applied as a gold paste having an average grain size of less than 5 micro-meters, the layer being between 2 to 30 micrometers thick, preferably 3 to 10 micrometers. The metal is part of a paste of the metal in an evaporative organic carrier. After screen printing, the carrier is eliminated by heating; subsequent heating converts the metal to a spongy microporous structure bonded to the substrate carrier by a diffusion zone.