Side Fringing of Thin Film Heads with Pole Trimming

Pole tips of a thin-film recording head are typically trimmed over some distance from the air bearing surface, leaving a shoulder on either side of the head. This shoulder can significantly modify the side reading characteristics of the head if it is within 6 um of the air bearing surface. We present experimental techniques to reveal the the shoulder effects on the side-reading, -writing and -erasing of the trimmed head. The influence of the shoulder on side reading, and the improvements one can achieve after this effect is minimized, are quantified. © 1990 IEEE