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:
Dec. 31, 1991
Filed:
Nov. 05, 1990
Charles F Carey, Endicott, NY (US);
Kenneth M Fallon, Johnson City, NY (US);
Rochelle Ginsburg, Vestal, NY (US);
Charles G Woychik, Endicott, NY (US);
International Business Machines, Armonk, NY (US);
Abstract
A controlled collapse chip connect method of joining an IC chip to a microelectronic circuit card. According to the method an inhomogeneous, anisotropic column of solder is deposited from a Pb/Sn alloy onto solder wettable I/O terminals of the I/C chip, without subsequent homogenizing reflow. The solder core has a Pb rich core and an Sn rich cap. The matching footprint of the solder wettable I/O terminals on the microelectronic circuit card is substantially free of deposited solder and presents a protected Cu surface to the solder columns, or, at most a surface of Cu and anti-oxidant. The chip is aligned with the corresponding footprints on the microelectronic circuit card, and the solder is reflowed to bond the chip to the microelectronic circuit card.