Browse Prior Art Database

Inductive Head with Robust P2 Pole Tip Design

IP.com Disclosure Number: IPCOM000106450D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Baratte, H: AUTHOR [+4]

Abstract

Disclosed is a new design for inductive magnetic heads.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Inductive Head with Robust P2 Pole Tip Design

      Disclosed is a new design for inductive magnetic heads.

      In the current head designs, the permalloy pole tip P2 sits on
'A'1 sub 'O' sub 3  (gap region) towards its lower end and on hard
bake photoresist towards its middle and upper part (Fig. 1).  The
point of stress inversion between the two situations, permalloy on
alumina and permalloy on resist, is located in the most sensitive
pole tip P2, so that almost every process variation results in
catastrophic instability failure.

      The new design inserts the first level of coils in alumina and
the second level in hard bake resist, which will at the same time
provide the slope for the rising pole tip P2 (Fig. 2).

      Thereby, the point of stress inversion between permalloy on
alumina and permalloy on resist is pushed further back to the yoke
area, i.e., out of the critical pole tip P2 region.  Thus, the pole
tip P2 is more stress insensitive to process variations.

      The total absolute vertical expansion of the pole tip P2 during
the processes is divided by the factor 2 since one half the thickness
of the I-layer is resist and the remaining half ('A'1 sub 2 'O' sub
3) has a thermal expansion 10-to-30 times less than alumina.