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:
Nov. 30, 2010
Filed:
Feb. 17, 2009
Ruisheng Wu, Shanghai, CN;
Yan Liu, Shanghai, CN;
Tao Feng, Santa Clara, CA (US);
Alpha and Omega Semiconductor Incorporated, Sunnyvale, CA (US);
Abstract
A wafer level chip scale package and method of laser marking the same are disclosed. The method includes forming a plurality of semiconductor devices on a frontside surface of a wafer, metallizing device contacts on the frontside surface of the wafer, grinding the backside surface of the wafer, silicon etching the backside surface of the wafer, laser marking the backside surface of the wafer following the silicon etch step, oxide etching the backside surface of the wafer following the laser marking step, depositing a metal layer on the backside surface of the wafer following the oxide etch step, and dicing the wafer into wafer level chip scale packages. A wafer level chip scale package includes a mark formed on a backside surface thereof, the mark comprising a plurality of trenches formed in a silicon backside surface and corresponding indentations formed in an overlaying back metal layer.