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:
Oct. 23, 2001
Filed:
Sep. 04, 1998
Mathias Boettcher, Dresden, DE;
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A plurality of uniform bumps are formed on a semiconductor device by forming a mask onto the surface of the semiconductor device with openings in the mask that correspond to the electrical contact pads on the surface of the semiconductor device. Solder or other conductive material is deposited on the pads. A rate of solder or other conductive material deposition which may not give a uniform thickness of solder or other conductive material across the surface of the wafer may be used. Solder or other conductive material is deposited until each opening in the mask is filled with solder or other conductive material. Next, the mask and solder or other conductive material balls formed are scrubbed until the mask and the soldier balls reach a substantially uniform height. The openings formed in the mask have substantially the same footprint or area associated with each pad. Since the solder or other conductive material balls are at the same height, the solder or other conductive material balls have approximately the same volume. The next step is to remove the mask and plating base metallization using a wet or dry etching process. If the material is solder, the next step is to reflow the solder to form substantially uniform solder balls or bumps on each pad across the wafer. The wafer is then diced to form individual chips having bumps which are uniform in height and volume.