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:
Mar. 19, 2002
Filed:
Dec. 20, 1999
Tai Min, San Jose, CA (US);
Otto Voegeli, Morgan Hill, CA (US);
Rongfu Xiao, Fremont, CA (US);
Cherng-Chyi Han, San Jose, CA (US);
Po-Kang Wang, San Jose, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
A magnetic shielding element for a magnetic recording and sensing device which prevents the problem of pop-corn noise or covariance of amplitude noise in the magnetic sensing device. The shielding element has a layer of antiferromagnetic exchange material formed on a layer of single domain first ferromagnetic material. The single domain first ferromagnetic material is stabilized by the antiferromagnetic exchange material. A layer of non-magnetic metal is then formed on the layer of antiferromagnetic exchange material and a layer of second ferromagnetic material is formed on the layer of non-magnetic metal to complete the shielding element. When the single domains of the first ferromagnetic material are disturbed by the strong magnetic fields of a write cycle they relax with a relaxation time of pico seconds and are fully relaxed before a read cycle begins. The fully relaxed layer of first ferromagnetic material then shields the magnetic sensing device from magnetic field fluctuations caused by the slower relaxation of the domains in the layer of second ferromagnetic material during a read cycle.