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:
Sep. 23, 2003
Filed:
Feb. 19, 2002
Lisa A. Fanti, Hopewell Junction, NY (US);
Randolph F. Knarr, Goldens Bridge, NY (US);
Erik J. Roggeman, Fishkill, NY (US);
Kamalesh K. Srivastava, Wappingers Falls, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Start with a semiconductor substrate with contacts exposed through an insulating layer. Form a base over the contacts, with the base composed of at least one metal layer. Then form a conductive metal layer over the base. Form a mask over the top surface of the conductive metal layer with C solder bump openings therethrough with the shape of C solder bump images down to the surface of the conductive metal layer above the contacts. Etch away the exposed portions of the conductive metal layer below the C solder bump openings to form through holes in the conductive metal layer exposing C solder bump plating sites on the top surface of the base below the C solder bump openings with the conductive metal layer remaining intact on the periphery of the through holes at the C solder bump plating sites. As an option, form a barrier layer over the plating sites next. Form C solder bumps on the plating sites on the base/barrier layer within the C solder bump openings, with the C solder bumps being in contact with the conductive metal layer on the periphery of the through holes. Remove the mask. Etch away the remainder of the conductive metal layer, and etch away the base aside from the C solder bumps forming BLM pads. Then reflow the C solder bumps to form C solder balls.