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:
Sep. 14, 1999
Filed:
Jul. 10, 1997
Peter W Robinson, Bradford, CT (US);
Deepak Mahulikar, Madison, CT (US);
Paul R Hoffman, Modesto, CA (US);
Advanced Interconnect Technologies, Inc., Manteca, CA (US);
Abstract
The bending of a ball grid array electronic package having a metallic base is reduced minimizing stresses applied to the innermost row of solder balls when the package base is cyclically heated and cooled. Reducing the stresses applied to the solder balls increases the number of thermal cycles before solder ball fracture causes device failure. Among the means disclosed to reduce the bending moment are a bimetallic composite base, an integral stiffener, a centrally disposed cover bonded to an external structure and a package base with a stress accommodating depressed portion.