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Method of Testing Burnishing Magnetic Heads

IP.com Disclosure Number: IPCOM000043659D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Hinkel, H: AUTHOR [+3]

Abstract

The test means used for burnishing magnetic heads is a special magnetic disk into which a radial groove has been burned by means of a laser beam, so that the burnishing magnetic head, provided with a piezocrystal, emits a signal every time it crosses the groove. The constancy of this signal indicates whether the head functions properly or not. In the last manufacturing step, the magnetic disk is slightly polished, with a burnishing magnetic head reducing disk asperities at a reduced flight height. The burnishing head is provided with a piezocrystal acting as an electroacoustic transducer, whose output signal during disk rotation remains below a predetermined level if the flight height of the burnishing magnetic head is sufficiently constant, i.e., if most asperities have been removed.

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Method of Testing Burnishing Magnetic Heads

The test means used for burnishing magnetic heads is a special magnetic disk into which a radial groove has been burned by means of a laser beam, so that the burnishing magnetic head, provided with a piezocrystal, emits a signal every time it crosses the groove. The constancy of this signal indicates whether the head functions properly or not. In the last manufacturing step, the magnetic disk is slightly polished, with a burnishing magnetic head reducing disk asperities at a reduced flight height. The burnishing head is provided with a piezocrystal acting as an electroacoustic transducer, whose output signal during disk rotation remains below a predetermined level if the flight height of the burnishing magnetic head is sufficiently constant, i.e., if most asperities have been removed. Both burnishing magnetic head and piezocrystal wear in the course of time and have to be replaced. It is extremely difficult, however, to determine after a certain period of time whether head and crystal are still functioning properly, so that they are generally replaced sufficiently early before their wear becomes excessive. As a result, burnishing heads are frequently prematurely discarded. To accurately determine the wear of burnishing magnetic heads and piezocrystals, so that they can be used for their full service life, a special magnetic disk is provided, by means of a laser beam, with a 0.2 to 0.9 mm wide radial groove which is slig...