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:
Apr. 23, 1991
Filed:
Nov. 28, 1989
William S Phy, Los Altos Hills, CA (US);
National Semiconductor, Santa Clara, CA (US);
Abstract
An improved tape automated bonding method of bonding the beam leads of lead frame tape to gold bumps formed on the contact pads of a semiconductor device, wherein the tape includes a plurality of interconnected beam leads defined by at least one opening in the tape such that each beam lead has an inner end and an outer end. The method includes the steps of depositing a gold layer on the beam leads, masking a region of each beam lead from further deposition of material such that a predetermined portion of each beam lead is exposed for further deposition of material, depositing a predetermined amount of tin on the exposed portion of each beam lead, establishing contact between each beam lead and the die bump to which each beam lead is to be bonded and applying a predetermined amount of pressure and heat to form a bond between each beam lead and the die bump to which the beam lead is to be bonded such that the bond formed includes the primary eutectic of the combination of tin and gold.