摘要 |
Thermal pole tip protrusion is caused by the materials in and around the head slider expanding during write operations till part of those materials protrude, leading to contact with the rotating disk surface, altering the flying height and often wearing down part of the disk surface. While it is well known that read-write heads expand during writing, the inventors are unaware of anyone else who recognized this situation's significance, particularly as the flying height decreases and the data rates increase, both of which are required for high areal density disk drives. The inventors realized that they could detect the problem at the spin stand level by testing head gimbal assemblies to reliably, and inexpensively, predict the tendency for thermal pole tip protrusion. This leads to selection of head gimbal assemblies, which do not have the thermal pole tip protrusion tendency. The selected head gimbal assemblies have better reliability, as do actuators and disk drives made with the selected head gimbal assemblies.
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