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Dynamic, In-Situ Take-Off Height Control for Effective Slider Burnishing

IP.com Disclosure Number: IPCOM000010440D
Original Publication Date: 2002-Dec-02
Included in the Prior Art Database: 2002-Dec-02
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Abstract

The procedure outlined solves the lack of burnishing efficiency of head disk interfaces that require burnishing. To reduce the magnetic spacing between the head and the disk, the allowance for interference is a promising solution path. However, the ever decreasing disk take-off height will limit the effectiveness of this solution significantly.

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Dynamic, In-Situ Take-Off Height Control for Effective Slider Burnishing

The method disclosed solves the lack of burnishing efficiency of head disk interfaces that require burnishing. To reduce the magnetic spacing between the disk and head design that allows burnishing is a promising solution path. However, the ever decreasing disk take-off height will limit the effectiveness of the solution significantly.

Problem statement: lack of burnishing power with low TOH disks

In case of very good TOH; the interface cannot be burnished to eliminate spacing sigmas. Hence interfering head disk interfaces will continue to interact without burnishing, which can lead to catastrophic failure of the hard disk interface.

Method to change the TOH in-situ

TOH was measured in drives built with sliders having different dynamic pitch (see results below). The table below shows that the effective TOH on low pitch sliders (PIR 37 and PIR38) is much higher than on the high pitch sliders (PIR41). Burnishing is done at a reduced rotational speed. With this understanding of "effective TOH", the ABS can include a design parameter such that during low speed burnishing, the slider pitch is low and during normal operation the slider pitch is high. This effectively allows for good burnishing properties while maintaining the effectively low TOH disk during normal operation.

#Hds TOH FH*StdMaxMinAvg Clearance (nm) Ser.No

PIR37 + WR1 PTA619

PIR37 + H-Tx PTA640

1.9 1.1 2.3 0.4 7.0

1.9 1.2 2.4 0.4 7....