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.

Date of Patent:
Dec. 08, 2009

Filed:

Aug. 30, 2007
Applicants:

Viraj Patwardhan, Milpitas, CA (US);

Hau Nguyen, San Jose, CA (US);

Inventors:

Viraj Patwardhan, Milpitas, CA (US);

Hau Nguyen, San Jose, CA (US);

Assignee:

National Semiconductor Corporation, Santa Clara, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 21/44 (2006.01);
U.S. Cl.
CPC ...
Abstract

A Micro SMDxt package is provided that configured for mounting to a circuit board. The SMDxt package includes a silicon-based IC having an array of contact pads on one side of thereof, and a die electrically attached to the silicon-based IC. A plurality of solder balls is included, each of which has a polymeric core surrounded by a metallic shell that in turn is surrounded by a layer of solder material. Further, each solder ball is positioned in contact with a corresponding contact pad of the package. An intertwined intermetallic fusion layer is formed through the fusion between material components of the contact pads and the solder material, via heat treatment. The intermetallic fusion extends between and from an outer surface of the metallic shell of each solder to an outer surface of a corresponding contact pad to form a high strength intermetallic solder joint therebetween.


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