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, 2002
Filed:
Jun. 23, 1999
Applicant:
Inventors:
Jorge Munoz, Cypress, CA (US);
Chuan Cheah, El Segundo, CA (US);
Assignee:
International Rectifier Corporation, El Segundo, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 2/348 ; H01L 2/352 ; H01L 2/940 ;
U.S. Cl.
CPC ...
H01L 2/348 ; H01L 2/352 ; H01L 2/940 ;
Abstract
A solderable back contact for semiconductor die consists of a titanium layer bonded to the bottom of the die. The free surface of the titanium layer is coated with a copper layer. A soft solder layer joins the bottom of the die to a copper lead frame by first heating the die to below the melting point of the solder, and then ultrasonically “scrubbing” the solder to cause it to bond to the die and lead frame with a minimum sized solder fillet.