THE EFFECTS OF POLE GEOMETRY ON RECORDING PERFORMANCE OF NARROW TRACK THIN-FILM HEADS

The effects of pole trimming on the recording performance of thin film heads is investigated through experiment and modeling. Three dimensional head fields are computed numerically for various pole geometries, and are used by a simple two dimensional recording simulation to determine written width, erase width, read width and isolated pulse response. These parameters are then compared to experimental values measured on trimmed and untrimmed heads. Both modeled and experimental parameters are then used as input to a system error rate simulation to determine the effects of pole trimming on system error rate as a function of track density. Good agreement is found between model and experimental parameters. The error rate results suggest that in a system with a reasonable track misregistration (TMR), a track density increase of 7 to 9% can be obtained by trimming the inductive head poles.