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:
Jan. 10, 2012
Filed:
May. 22, 2009
Tomohiro Hashii, Saga, JP;
Yasunori Yamada, Saga, JP;
Yuichi Kakizono, Saga, JP;
Sumco Corporation, Tokyo, JP;
Abstract
A method of grinding semiconductor wafers including simultaneously grinding both surfaces of multiple semiconductor wafers by rotating the wafers between a pair of upper and lower rotating surface plates in a state where the wafers are held on a carrier so that centers of the wafers are positioned on a circumference of a single circle, wherein a ratio of an area of a circle passing through the centers of the wafers to an area of one of the wafers is greater than or equal to 1.33 but less than 2.0; surfaces of the fixed abrasive grains comprised in the surface plates are comprised of pellets disposed in a grid-like fashion, with the pellets provided in a center portion and pellets provided in a peripheral portion being larger in size than the pellets provided in an intermediate portion.