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. 22, 2003
Filed:
Jul. 18, 2000
Katsutoshi Muramatsu, Kuwana, JP;
NTN Corporation, Osaka, JP;
Abstract
Silicon balls of single crystal silicon for use in semiconductir circuit substrates or the like, which have been lapped to satisfy necessary requirements and a method of making the same. The silicon ball of single crystal silicon is a lapped ball of single crystal silicon having a sphericity of not greater than 0.08 &mgr;m and also having a residue stress layer of not greater than 5 &mgr;m in a depth from a processing surface thereof on one side in negative and positive directions. The method of making the silicon balls makes use of a pair of lapping tables and supported in face-to-face relation with each other. One or both of the lapping tables and is prepared from finely divided abrasive particles hardened by the use of a resinous bonding material. Workpieces W of single crystal silicon are sandwiched between the lapping tables and and are lapped to provide the lapped balls.