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:
Jul. 11, 2000
Filed:
Jan. 22, 1999
Susan J Swindlehurst, Redwood City, CA (US);
Hubert A Vander Plas, Palo Alto, CA (US);
Jacques Leibovitz, San Jose, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A method of forming solder bumps on a wafer. The wafer includes at least one substrate, a plurality of solder-wettable pads and a solder wettable retention ring about the periphery of the wafer. The method of forming solder bumps includes forming a non-solder-wettable mask on the wafer which includes a plurality of apertures which align with the solder-wettable pads, and the solder wettable retention ring surrounds the mask. The mask and wafer are positioned within an aperture of a stencil so that the solder wettable retention ring aligns with a gap between the periphery edge of the mask and an inside edge of the aperture of the stencil. Solder paste is applied to the mask so that the solder paste fills the apertures of the mask and the gap. The solder paste is reflowed forming solder bumps on the pads and a solder ring on the solder wettable retention ring. The mask is removed after formation of the solder bumps.