Browse Prior Art Database

WAFER LEVEL OVERCOAT ETCH TO PREVENT PROTRUSION

IP.com Disclosure Number: IPCOM000014080D
Original Publication Date: 1999-Dec-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 36K

Publishing Venue

IBM

Related People

J TABIB: AUTHOR [+4]

Abstract

An economical wafer level process is disclosed for reducing overcoat (OC) protrusion on an MR head. This technique uses a wafer level etching process to remove the protruding material, and can result in allowing the magnetic fly height to be decreased.

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WAFER LEVEL OVERCOAT ETCH TO PREVENT PROTRUSION

     An economical wafer level process is disclosed for reducing overcoat (OC) protrusion on an MR head. This technique uses a wafer level etching process to remove the protruding material, and can result in allowing the magnetic fly height to be decreased.

      In this disclosed process, the wafer is subjected to a masking process to expose the portion of overcoat which will protrude at the slider level, and to protect the other structures on the wafer. The wafer is then immersed into an etchant, (in this case EDTA for Al2O3), to etch away the overcoat material. The etch depth is controlled by time. Since the overcoat near the pole piece has much slower etch rate, this provides an etch stop to prevent severe over etch. The EDTA etch for Al2O3 is known to undercut the resist mask which in turn creates a very gently sloped etch pocket wall. By creating a gentle slope, chipping and cracking during fabrication can be minimized. Since the mask is aligned at wafer level, it is easy to align the etch pocket with respect to the pole piece, hence very precise alignment and etch can be accomplished. Furthermore, the size and shape of the etch pocket can be designed and optimized to etch various head/slider types, and completely eliminate the overcoat protrusion problem.

By using a wafer level process many sliders can be processed at once making the disclosed process very economical compared with row level or individual slider level pr...