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:
May. 28, 1996
Filed:
May. 22, 1995
Applicant:
Inventors:
Hideo Kaneko, Kanagawa-ken, JP;
Yasuaki Nakazato, Nagano-ken, JP;
Toyofumi Aoki, Nagano-ken, JP;
Itsuo Kuroyanagi, Chiba-ken, JP;
Assignee:
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; H01L / ;
U.S. Cl.
CPC ...
360135 ; 437947 ; 1566441 ; 1566571 ;
Abstract
Proposed is a substrate of a magnetic recording medium in the form of an annular disk made from a single crystal of silicon which is imparted with greatly improved mechanical strengths to withstand mechanical shocks and high-velocity revolution. Different from conventional annular disks as formed by a mechanical working to form the outer contour and the circular center opening, the peripheral surfaces of the inventive annular disk are freed from the work-stressed surface layer by a chemical etching treatment undertaken after the mechanical working.