Patent ID: 6842308

Claim:
A head for a magnetic drive, comprising: a substrate defining a generally planar air bearing surface and arranged with a face substantially in the plane of the air bearing surface and with a thermal expansion rate CTE 1 ; a transducer that has a bond to the substrate on a first side and having a transducer thermal expansion rate CTE 2 that is greater than CTE 1 such that the transducer expands relative to the substrate with increasing temperature in a first direction perpendicular to the plane of the substrate, the transducer having a face in the plane of the air bearing surface; and a first restraint layer that has a bond to a second side of the transducer, opposite the first side, and that has a first restraint layer thermal expansion rate CTE 3 that is less than CTE 1 , the first restraint layer having a thickness of at least 2 μm and a thermal expansion rate CTE 3 of about 1×10 −6 /° C. to 4.3×10 −6 /° C., whereby the first restraint layer contracts relative to the substrate with increasing temperature in a second direction which is perpendicular to the plane of the substrate and opposite the first direction to reduce a distance of a thermal protrusion of the transducer beyond the plane of the substrate and maintain the arrangement of the face of the transducer substantially in the plane of the air bearing surface of the substrate.