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. 23, 2011
Filed:
Feb. 03, 2009
Luc L. Belanger, Quebec, CA;
Marc A. Bergendahl, Troy, NY (US);
Ajay P. Giri, Poughkeepsie, NY (US);
Paul A. Lauro, Brewster, NY (US);
Valerie A. Oberson, Alphonse de Granby, CA;
Da-yuan Shih, Poughkeepsie, NY (US);
Luc L. Belanger, Quebec, CA;
Marc A. Bergendahl, Troy, NY (US);
Ajay P. Giri, Poughkeepsie, NY (US);
Paul A. Lauro, Brewster, NY (US);
Valerie A. Oberson, Alphonse de Granby, CA;
Da-Yuan Shih, Poughkeepsie, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Methods and UBM structures having bilayer or trilayer UBM layers that include a thin TiW adhesion layer and a thick Ni-based barrier layer thereover both deposited under sputtering operating conditions that provide the resultant bilayer or trilayer UBM layers with minimal composite stresses. The Ni-based barrier layer may be pure Ni or a Ni alloy. These UBM layers may be patterned to fabricate bilayer or trilayer UBM capture pads, followed by joining a lead-free solder thereto for providing lead-free solder joints that maintain reliability after multiple reflows. Optionally, the top layer of the trilayer UBM structures may include soluble or insoluble metals for doping the lead-free solder connections.