Data storage devices store digitally encoded information on discs. Heads read data from or write data to discs which are supported for rotation relative to a base chassis by a spindle motor or drive. Heads include transducer elements, such as magnetoresistive, magneto-optical or inductive elements for read or write operations. An actuator assembly moves the head relative to select data tracks on the disc for read or write operations.
Typically the head includes an air bearing slider which is coupled to a head suspension assembly. Rotation of the disc creates an air flow along the air bearing slider to provide a lift force. The lift force of the air bearing slider is countered by a load force supplied via a load beam of the suspension assembly to define in part a fly height of the slider. The slider is coupled to the head suspension assembly via a gimbal spring so that the slider pitches and rolls to follow the topography of the disc surface. Typically the slider flies at a pitch angle so that a trailing edge of the slider defines a close point of the slider relative to the disc surface. During operation, the air bearing compensates for shock or vibration to maintain a stable fly height for the slider above the disc surface.
The transducer elements of the head are fabricated on the trailing edge of the slider. Typically the transducer elements are embedded in a thermally expandable substrate or body such as Alumina Al2O3. Thermal expansion of the transducer portion via changes in ambient drive temperature or via heat generated by write current can cause transducer elements to protrude (i.e. pole tip protrusion) below air bearing surfaces of the slider. Protrusion of the transducer elements or pole tip protrusion can compromise effect of the air bearing to maintain a stable fly height between the slider and the disc surface. Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.