Minimizing pole-tip recession caused by lapping thin-film tape-recording heads

When thin-film magnetic tape-recording heads are diamond lapped during manu facture, wear-rate differences between the ceramics and the thin films on t he lapped surface cause pole-tip recession (PTR). PTR results in an increas ed recorded transition length as well as a significant signal loss in high- density recorded data. Currently PTR is corrected through a secondary proce ss that is both expensive and time consuming. In this paper; we present the results of a Taguchi optimization experiment that was designed to minimize PTR caused by diamond lapping. An L32 Taguchi screening experiment identif ied the important factors to be plate condition, plate type, lubrication an d slurry type. A subsequent L18 Taguchi optimization experiment identified that an alumina lapping plate used in conjunction with water-based slurry r esulted in the least PTR after the plate had been used in 20 h of lapping. The implications of the results to thin-film tape-head manufacturing are di scussed in detail.