Head having a transducer heater and an air bearing surface with a flow-diversion dam and pressure-relief trough disposed upstream of the transducer

A head comprising:

• a transducer including at least a read transducer and a heating element;
• and
• a slider having an air bearing surface, the air bearing surface defining an upstream direction and a lateral axis that is orthogonal to the upstream direction, the air bearing surface including:
• a leading pad including a major surface in a first plane;
• a sub-ambient pressure cavity adjacent the leading pad, the sub-ambient pressure cavity including a surface that is recessed from the first plane;
• a transducer pad, the transducer pad defining a total width measured parallel to the lateral axis, the transducer pad including a face of the transducer and including a surface that lies in the first plane;
• a pressure-relief trough recessed from the first plane by at least 0.1 microns and having a breadth measured in the upstream direction of no more than one fourth of a total length of the slider, the pressure-relief trough being disposed immediately upstream of the transducer pad and continuously spanning the total width of the transducer pad;
• and
• a flow-diversion dam including a dam surface that lies in the first plane, the dam surface continuously spanning the total width of the transducer pad, the dam surface being disposed immediately upstream of the pressure-relief trough and generally downstream of the sub-ambient pressure cavity, and wherein the dam surface is shared like a letter W that is oriented so that the center peak of the W extends further upstream than the bottom points of the W.