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. 31, 2013
Filed:
Dec. 23, 2009
Shanlin Duan, Fremont, CA (US);
Jizhong He, San Jose, CA (US);
John S. Hopkins, Gilroy, CA (US);
Kenneth E. Johnson, Morgan Hill, CA (US);
Shanlin Duan, Fremont, CA (US);
Jizhong He, San Jose, CA (US);
John S. Hopkins, Gilroy, CA (US);
Kenneth E. Johnson, Morgan Hill, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
A tool for testing a magnetic disk for use in a magnetic disk drive. The tool detects surface defects or asperities by detecting a change in electrical resistance corresponding to a temperature change in a thermally sensitive layer. The apparatus includes a slider body having a thermally insulating layer formed on an air bearing surface of the slider body and a thermal sensor layer formed on the thermally insulating layer. The thermally insulating layer prevents thermal heat spikes in the thermal sensor layer (such as resulting from contact with an asperity) from dissipating quickly into the slider body itself. The thermal sensor layer is a material that exhibits a change in electrical resistance in response to a change in temperature and is preferably a PTC thermistor material which exhibits a large change in electrical resistance when a transition temperature has been reached.