Batch fabricated servo write head having low write-gap linewidth variation

摘要

A batch fabrication technique is described that increases the manufacturing efficiency of servo write heads and also improves servo pattern definition for fine features, while reducing tape and head wear. Multiple heads are fabricated as a batch from one or more ferrite wafers. A nominally flat, large wafer surface and a contour suitable for uniform photoresist application and planar photolithography permit fine servo pattern definition with low linewidth variation. Non-magnetic material is photolithographically defined to produce gaps above the spacer. The non-magnetic material may be photoresist, semiconductor materials, glass, metal or the like. The material may even be removed later to leave air gaps. The non-magnetic material forms a region where the field loops out to intersect the passing tape, thereby transferring a magnetic pattern to tape. Additionally, a lower ferrite wafer may be mated to the upper ferrite wafer to complete a magnetic circuit around the gaps. The upper or lower ferrite wafer may have a channel through which an inductive winding passes. Multiple heads may be formed through batch processing of the upper and lower ferrite wafers.