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:
Apr. 06, 2004
Filed:
Aug. 30, 2002
Korea Advanced Institute of Science and Technology, Taejeon, KR;
Abstract
Disclosed is a fabrication method of UBM for flip chip interconnections of a semiconductor device, consisting of dipping a patterned wafer into a plating solution containing materials supplying nickel and copper ions, forming a copper layer at a predetermined current density for connection between a chip pad and a solder bump and for residual stress-buffering, and forming a nickel-copper alloy layer at an increased current density for prevention of diffusion between the solder and the pad. The method is advantageous in terms of low fabrication cost due to not requiring an etching process, while meeting the conditions of wettability, diffusion-barrier function and small residual stress required to form UBM on the patterned wafer.