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. 04, 1978
Filed:
May. 14, 1976
Applicant:
Inventors:
Assignee:
The Welding Institute, , GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B23K / ; H01L / ;
U.S. Cl.
CPC ...
228-45 ; 219 68 ; 219 861 ; 228111 ; 219 7613 ;
Abstract
Difficulties in forming a ball on the end of a wire of aluminium or aluminium alloy for ball bonding are overcome by applying between the wire and an electrode a low voltage, typically 30 volts, and bringing the wire and electrode into temporary contact to fuse the wire and initiate a spark discharge which results in the formation of a ball on the wire end. The spark discharge takes place in a shielding gas to avoid oxidation of the ball.