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:
Jun. 30, 1987
Filed:
Jul. 15, 1986
Edward T Yen, San Jose, CA (US);
International Business Machines, Armonk, NY (US);
Abstract
Method and apparatus for controlling the throat height of batch fabricated thin film magnetic transducers. During deposition of the transducer elements on a substrate, a resistive electrical lapping guide is deposited on at least one end of the array of transducer elements. The electrical lapping guide includes a plurality of switching junctions formed between a section of electrically resistive material and conductors. At least one switching junction is deposited on the substrate having a known switching plane position. During lapping of the transducer pole tip ends to a final height, the switching junction will change state to provide an accurate indication of the lapped throat height. The throat height, as determined from measured resistance of the lapping guide, is compared to the switching junction position at the time said switching junction changes state. Subsequent resistance measurements are calibrated in light of this comparison.