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. 20, 2002
Filed:
Jul. 10, 1996
Cynthia Melton, Bolingbrook, IL (US);
Theresa L. Baker, Schaumburg, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A microelectronic package ( ) comprises an integrated circuit component ( ) mounted on a substrate ( ) by solder bump interconnections ( ) formed of a lead-free, tin-base solder alloy that contains a significant copper addition. A preferred solder is composed of a tin alloy containing between about 2 and 8 weight percent copper, preferably between about 3 and 5 weight percent. In the absence of lead, it is found that precipitation of copper-containing intermetallics of the type that adversely affect tin-lead solders is reduced. Moreover, the lead-free copper-tin solder alloy exhibits a high surface tension to reduce collapse of component toward the substrate during solder reflow.