Browse Prior Art Database

Helical Coil Process

IP.com Disclosure Number: IPCOM000106335D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Tang, DD: AUTHOR

Abstract

Disclosed is a method for fabricating helical coils for flat yoke head structures. After the lower coil is plated, it is insulated with a hardbake photoresist, leaving the ends of the lower coils open for connection. Fig. 1 (a) shows the photoresist profile of a conventional helical coil process. An approximately 11 mm photoresist must be opened at the lower coil layer and only an approximately 4 mm photoresist is to be opened at the top of the yoke.

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Helical Coil Process

      Disclosed is a method for fabricating helical coils for flat
yoke head structures.  After the lower coil is plated, it is
insulated with a hardbake photoresist, leaving the ends of the lower
coils open for connection.  Fig. 1 (a) shows the photoresist profile
of a conventional helical coil process.  An approximately 11 mm
photoresist must be opened at the lower coil layer and only an
approximately 4 mm photoresist is to be opened at the top of the
yoke.

      Such a large topography strains the exposure and development
protoresist and degrades the best achievable coil pitch.  The
inspection for the remaining photoresist in the deep and narrow wells
is difficult in a manufacturing enviroment.  Having the coil
extensions (Fig. 1 (b)) the topography is reduces to 4-6 mm.  Thus,
the photolithographic process is eased and finer coil pitch becomes
possible.  The removal of the plating seedlayer also becomes easier;
since the hardbake photoresist fills the gap between the coil
extensions and the yoke, the plating seedlayer of the top coil layer
is deposited over a rather planar surface.