Design issues for practical rigid disk magnetoresistive heads

Some of the issues of magnetoresistive (MR) head design are discussed from the point of view of practical, high-reliability, low-cost, manufacturable heads for rigid disk files. The major advantages of MR heads over single element inductive thin-film heads are that the MR head gives an ideal, easy to equalize output waveshape, can be used on disks with high coercivities for high linear densities, and is less subject to stability problems at narrow trackwidths. The major advantages of MR heads over metal-in-gap ferrite heads are in narrow trackwidth and high-frequency potential. Disadvantages of MR heads in the rigid disk environment include concerns about reliability and, more specifically, possible environmental fragility, loss of performance due to imperfect alignment between the read and write elements and/or due to signal asymmetry, and the possibility of higher cost/price