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Creation of an Air Bearing Surface by Excimer Laser Patterning of Ceramic

IP.com Disclosure Number: IPCOM000121630D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 100K

Publishing Venue

IBM

Related People

Brannon, J: AUTHOR [+4]

Abstract

We describe a technique for the fabrication of patterned Air Bearing Surface (ABS) sliders from a polished row of magnetic heads using short-duration ultraviolet (UV) laser pulses of appropriate fluence, shape and repetition rate to irradiate the ceramic. Short-duration minimizes any thermal spreading, while deep UV wavelengths cause controlled ablation of the slider ceramic material and thin-film alumina coating. We have successfully fabricated inductive and magneto-resistive (MR) sliders using this technique.

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Creation of an Air Bearing Surface by Excimer Laser Patterning of
Ceramic

      We describe a technique for the fabrication of patterned
Air Bearing Surface (ABS) sliders from a polished row of magnetic
heads using short-duration ultraviolet (UV) laser pulses of
appropriate fluence, shape and repetition rate to irradiate the
ceramic.  Short-duration minimizes any thermal spreading, while deep
UV wavelengths cause controlled ablation of the slider ceramic
material and thin-film alumina coating.  We have successfully
fabricated inductive and magneto-resistive (MR) sliders using this
technique.

      Prior art for slider fabrication include mechanical grinding,
and YAG-laser milling.  Mechanical grinding is difficult for both
curved ABS contours and for small ABS patterns. YAG laser milling
[1,2] is based on the well-known technique of laser-scribing that is
extensively used.  The feasibility of YAG scribing for possible ABS
patterning has been demonstrated [1,2], but the technique suffers
from the following constraints:  (a) extensive amounts of strongly
adhering, rede posited debris (redep) near the ABS rail if done in
air; (b) poor etch-depth control expected; (c) chemical etching (hot
phosphoric acid) of the alumina overcoat is needed since the YAG
laser is incapable of controllably ablating the alumina layer; (d)
any YAG light leaking into the (transparent) alumina overcoat will
damage the thin- film metallurgy; (e) the YAG laser patterns only by
a serial scanning process, which is slower and less efficient than a
parallel patterning scheme used by the excimer laser.

      In recent years, excimer lasers have been used in a variety of
etching or ablative techniques [3,4] for directly patterning
surfaces.  Common to these schemes is the use of image projection - a
parallel processing method which permits simultaneous and efficient
patterning of relatively large surface areas.  Initial attempts at
slider fabrication by 308 nm ablation of ceramics met with only
partial success.  Although 308 nm radiation will cause ablation of
the A1203/TiC ceramic, it is less efficient in ablating the alumina
overcoat resulting in an alumina fence at the end of the ceramic.
Hence, we develop the 248 nm excimer laser process as indicated in
Table I.  We have tried the deep UV laser machining on many rows,
using both contact printing approach and the projection printing
approach.  For example, we have used contact etching on 30 rows of
sliders at a laser repetition (rep) rate of ten...