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. 03, 2013
Filed:
Jan. 10, 2011
Hong-sik Jung, Pleasanton, CA (US);
Emur M. Velu, Fremont, CA (US);
Sudhir S. Malhotra, Fremont, CA (US);
Jackie Tsoi Jung, Cupertino, CA (US);
Gerardo A. Bertero, Redwood City, CA (US);
Hong-Sik Jung, Pleasanton, CA (US);
Emur M. Velu, Fremont, CA (US);
Sudhir S. Malhotra, Fremont, CA (US);
Jackie Tsoi Jung, Cupertino, CA (US);
Gerardo A. Bertero, Redwood City, CA (US);
WD Media, LLC, San Jose, CA (US);
Abstract
A perpendicular magnetic recording disk having a single domain exchange-coupled laminated soft magnetic underlayer (SUL) is disclosed. The SUL is a combination synthetic anti-parallel coupled SUL structure, which has the product (Mst) of saturation magnetization and film thickness of the middle ferromagnetic layer less than the sum of the Mst of the bottom and top ferromagnetic layers. Subjected to a post radial field reset process, this SUL provides single domain state. Moreover, both robustness of stray fields and low permeability are obtained while keeping excellent corrosion resistance and cost effective manufacturability.