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:
Apr. 26, 2011
Filed:
Dec. 26, 2007
Donald G. Allen, Morgan Hill, CA (US);
Hieu Lam, Milpitas, CA (US);
Terence Tin-lok Lam, Cupertino, CA (US);
Steve C. Puga, Morgan Hill, CA (US);
Donald G. Allen, Morgan Hill, CA (US);
Hieu Lam, Milpitas, CA (US);
Terence Tin-Lok Lam, Cupertino, CA (US);
Steve C. Puga, Morgan Hill, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Methods and structures for the fabrication of both thin film longitudinal and perpendicular write heads are disclosed. A unique feature of these write heads is the inclusion of layered return poles, which comprise alternating layers of 22/78 and 80/20 NiFe alloys. The alternating layers also vary in thickness, the 22/78 NiFe layers having a nominal thickness of 1500 angstroms and the 80/20 NiFe layers having a nominal thickness of about 75 angstroms. Head efficiency and signal to noise ratios are significantly improved in heads having layered return pole construction.