公开(公告)号：DE2341648A1

公开(公告)日：1974-04-25

申请号：DE2341648

申请日：1973-08-17

Applicant: IBM

Inventor： ABBOTT CHESTER DANIEL ,  BROCK GEORGE WILLIAM ,  ROBINSON NEIL LLOYD ,  SHELLEDY FRANK BOYD ,  SMITH SIDNEY HENRY

IPC: B24B49/00 ,  G11B5/187 ,  G11B5/23 ,  G11B5/31 ,  G11B5/42

Abstract: 1420130 Making magnetic heads INTERNATIONAL BUSINESS MACHINES CORP 11 Sept 1973 [11 Oct 1972] 42651/73 Heading G5R In a method of making magnetic heads to obtain a desired throat height an electrically conductive film 2, 3, 4 is deposited on a substrate 1 to form a plurality of heads 2, 3 each having a transducing element conductive film portion with an initial excess of material on one side, and there being a bridge conductive film portion 4 connecting the transducing element portions of adjacent heads, the bridge being located on the side with the initial excess of material, a respective pair of leads 5, 6, 7, 8 for each head are arranged so that the leads are connected by the transducing element portion of the respective head, the resistance of the bridge portion is then monitored through two leads connected to different heads whilst removing material at a first rate from the bridge portion and substrate until the monitored resistance indicates circuit discontinuity between the transducing element portions of the heads initially connected by the bridge portion, and then the resistance of at least one transducing element portion is monitored through the leads eonnected thereto whilst removing material at a second rate from the one side of the transducing element portions and substrate until the resistance or resistances being monitored has or have reached a predetermined value indicative of the desired throat height. The method may be applied to multiturn heads or single turn heads, e.g. as disclosed in Specifications 1,343,860 and 1,372,474, and of inductive type having a copper film 2, 3 single turn with a nickel-iron alloy magnetic yoke 9, 9 1 , or of magnetoresistive type having a single magnetoresistive turn on a nickel-iron substrate. The material removal may be by grinding, lopping or weaving or by electrochemical techniques. Bridges 4 between adjacent conductor elements 2, 3 of a multitrack head may be rough ground whilst monitoring the resistance of each bridge in turn, e.g. via leads 5, 8 and scanning switchgear, Fig. 4 (not shown), until a desired number of bridges break, indicated by open circuits. The heads are then fine ground whilst monitoring the resistance of each element 2, 3 in turn. The head assembly may be adjusted in any of two or three axes during grinding to provide uniform material removal and compensation for fabrication tolerances, uneven removal being indicated by different monitored resistances. The grinding operations may be computer controlled.