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Browse Prior Art Database

Electrical Lapping Guide

IP.com Disclosure Number: IPCOM000034387D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Cannon, DM: AUTHOR

Abstract

In high performance inductive heads for tape drives and other magnetic recording devices, it is critical that the throat height of the head be tightly controlled. Such control can be provided by lapping guides. Two examples of lapping guides are described in U.S. Patent 3,821,815 and IBM Technical Disclosure Bulletin 25, 6347 (May 1983). However, the techniques for forming lapping guides in the prior art make it difficult to provide a precisely controlled throat height for heads in which the inductive coil is buried in a recess etched into the substrate. The reason for this is that these lapping guides are designed for measurement of the throat height with reference to the position of the coils rather than the edge of the recess.

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Electrical Lapping Guide

In high performance inductive heads for tape drives and other magnetic recording devices, it is critical that the throat height of the head be tightly controlled. Such control can be provided by lapping guides. Two examples of lapping guides are described in U.S. Patent 3,821,815 and IBM Technical Disclosure Bulletin 25, 6347 (May 1983). However, the techniques for forming lapping guides in the prior art make it difficult to provide a precisely controlled throat height for heads in which the inductive coil is buried in a recess etched into the substrate. The reason for this is that these lapping guides are designed for measurement of the throat height with reference to the position of the coils rather than the edge of the recess. This requires the precise alignment of the coil mask to the edge of the recess, and it is very difficult to achieve absolute alignment. The present article describes a procedure for avoiding this stringent alignment requirement. As shown in Fig. 1, coils 1 are deposited on a recessed area 2 of a substrate 3. The throat height of the head is defined by the distance between the edge 4 of recessed area 2 and the lapped air bearing surface 5. The distance between edge 4 and surface 5 can be tightly controlled by forming masks on the surface of the substrate in the manner shown in Fig. 2. A conducting film 6 for the lapping guide 7 is deposited on the surface of the substrate 3 prior to etching the recessed area 2 in...