Narrow Track MR Head Technology

Narrow track technologies for shielded MR heads are discussed in terms of off-track performance and increased head output. Permanent magnet bias heads are increasingly superior to exchange coupling bias heads as tracks become narrower, because of the excellent off-track performance of the permanent magnet type. Increasing the sense current is one way to increase head output. However, the current increase raises the temperature of the MR element and degrades performance. An analysis of the thermal behavior of the shielded MR head shows that increasing the thermal conduction of the shield and gap layers, which are the main sources of heat radiation, and improving the crystalline properties of the Ni-Fe film effectively suppress the rise in temperature of the MR element.