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. 17, 1999
Filed:
Jul. 09, 1997
Inderjit Singh, San Jose, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An improved capillary construction that includes a cavity suitable for at least partially molding a ball bond during a ball bonding operation as well as methods for wire bonding utilizing such a capillary are described. More specifically, a distal end of a bonding wire that passes through the capillary is ultrasonically welded to a bonding surface in a manner such that the cavity molds a significant portion of the ball bond during the ball bonding operation. The described arrangement permits the bonding force applied by the bonding machine that drives the capillary to be significantly reduced or eliminated. In some embodiments, the capillary is positioned at a predetermined standoff height relative to the bonding surface. The described arrangements have numerous advantages and permits bonding to bonding surfaces that are heated to a temperatures of less than approximately 150 degrees centigrade during the ultrasonic welding step. The resultant bonds tend to have significant intermetallic bonding over a majority of a contact surface between the ball bond and the bonding surface. The described capillary and methods works well with fine pitch devices, including devices having pitches of 70 microns or less.