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. 16, 2000
Filed:
Jun. 15, 1998
Applicant:
Inventors:
Shigeru Shouji, Hamamatsu, JP;
Masahiro Sugiura, Hamamatsu, JP;
Assignee:
Yamaha Corporation, , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; C23F / ;
U.S. Cl.
CPC ...
2960312 ; 2960316 ; 2960318 ; 216 47 ; 216 66 ;
Abstract
A first resist mask is formed on a rail, covering an area where none of a shallow surface and a deep surface are formed. A first etching process is performed to etch the rail not covered with the first resist mask to a depth corresponding to the shallow surface. Next, without removing the first resist mask, a second resist mask is formed covering an area where the shallow surface is formed. A second etching process is performed to etch the rail not covered with the first and second resist masks, to a depth corresponding to the deep surface. After the first and second etching processes, the first and second resist masks are removed from the rail.