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:
Aug. 21, 2001
Filed:
May. 28, 1999
Inderjit Singh, San Jose, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A bond pad sealing arrangement and method that utilizes ball bonds to protect a bond pad is described. A relatively large free air ball is formed at a distal end of a bonding wire used for ball bonding. The free air ball is pressed against a bond pad and ultrasonically welded to form a ball bond. The bonding parameters utilized during the ball bonding are selected such that excess ball material passes is squashed outward beyond the capillary tip and overflows the periphery of the bond pad thereby completely covering and sealing the bond pad. The described structure works well to protect aluminum and other bond pads that are subject to corrosion if left exposed. In one preferred arrangement the capillary used to form the ball bond includes a cavity arrangement that molds a central portion of the ball bond to form a good intermetallic bond between the bond pad and the bonding wire.