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:
Dec. 14, 2004
Filed:
Apr. 25, 2000
John Hsieh, San Jose, CA (US);
Robert M. Tierney, Fremont, CA (US);
Asahi Glass Company, Ltd., Tokyo, JP;
Abstract
A method for forming a magnetic disk comprises the following steps. First, an inner and outer cut is provided in a work piece. The waste piece thus comprises an outer waste piece, an inner waste piece, and a region between the inner and outer waste pieces that is to be used as a substrate for manufacturing a magnetic disk. The outer waste piece is separated from the substrate by applying a hot plate against the outer waste piece, thereby causing it to thermally expand and separate from the substrate. The substrate is then placed over (but not in contact with) a hot plate, while a cooling element is placed on the inner waste piece. This causes the substrate to thermally expand while the inner waste piece thermally contracts. Thus, a gap forms between the substrate and inner waste piece, thereby permitting the separation of the inner waste piece from the substrate.