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:
Nov. 21, 2006
Filed:
Sep. 30, 2004
Ciaran Avram Fox, Sunnyvale, CA (US);
Kenneth David Mackay, San Jose, CA (US);
Vladimir Nikitin, Campbell, CA (US);
Ciaran Avram Fox, Sunnyvale, CA (US);
Kenneth David Mackay, San Jose, CA (US);
Vladimir Nikitin, Campbell, CA (US);
Hitachi Global Storage Technologies Netherlands, B.V., Amsterdam, NL;
Abstract
A method is disclosed for testing pinned layers of magnetic disk drive read heads having at least one pinned layer, where the magnetic orientation of the pinned layers has been set in an initial direction. The method includes applying a large magnetic test field at a reverse canted reset angle. First test responses from the disk drive read heads are then measured in a small magnetic test field. A large magnetic test field is applied at normal canted reset angle. The disk drive heads are then subjected to a full suite of performance tests in a small magnetic test field to verify their acceptability. These second test responses are then compared to the first test responses to identify read heads having weakly pinned layers.