Patent ID: 8817425

Claim:
A read head structure; comprising: (a) a dynamic fly height (DFH) element formed on a substrate, the DFH element is recessed a first distance (d 1 ) from an air bearing surface (ABS) and has a top surface and sides that contact a first insulation layer, the DFH element expands when heated and pushes the read head structure toward a magnetic medium that is proximate to the ABS; (b) a dual piece heat sink (HS) layer including a front piece and a back piece each having a top surface substantially formed in a first plane, the front piece is recessed a second distance (d 2 ) from the ABS where d 2 <d 1 , and is aligned above a front portion of the DFH heater element while the back piece is aligned above a back portion of the DFH heater element, a front side of the back piece that faces the ABS is separated from a back side of the front piece by a gap that is filled with a second insulation layer; and (c) a bottom (S1) shield formed on a portion of the first insulation layer and that contacts the top surface of the front piece, the S1 shield has a front side along the ABS and a first thickness (t 1 ) in a down-track direction in a front section adjoining the ABS, and a second thickness (t 2 ) in the down-track direction in a back section formed over the front piece where t 1 >t 2 .