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:
Nov. 17, 2015
Filed:
Jun. 24, 2011
Sihai Chen, NewHartford, NY (US);
Ning-cheng Lee, New Hartford, NY (US);
Sihai Chen, NewHartford, NY (US);
Ning-Cheng Lee, New Hartford, NY (US);
Indium Corporation, Clinton, NY (US);
Abstract
A process of making efficient metal bump bonding with relative low temperature, preferably lower than the melting point of Indium, is described. To obtaining a lower processing temperature (preferred embodiments have a melting point of <100° C.), a metal or alloy layer is deposited on the indium bump surface. Preferably, the material is chosen such that the metal or alloy forms a passivation layer that is more resistant to oxidation than the underlying indium material. The passivation material is also preferably chosen to form a low melting temperature alloy with indium at the indium bump surface. This is typically accomplished by diffusion of the passivation material into the indium to form a diffusion layer alloy. Various metals, including Ga, Bi, Sn, Pb and Cd, that can be used to form a binary to quaternary low melting point alloy with indium. In addition, diffusion of metal such as Sn, Sn—Zn into Ga—In alloy; Sn, Cd, Pb—Sn into Bi—In alloy; Cd, Zn, Pb, Pb—Cd into Sn—In alloy can help adjust the melting point of the alloy.