Patent ID: 8767349

Claim:
A stitched pole magnetic write head, having an air bearing surface (ABS), comprising: (a) a magnetic pole structure comprising: (1) on a substrate, a first layer of high magnetic permeability material that serves as a primary lower magnetic pole having a top surface and a thickness, the primary lower magnetic pole has a first end that is recessed from the ABS by a first distance and a second end formed at a back end of the magnetic pole structure wherein the primary lower magnetic pole has a first thickness at the first end and second end, and a second thickness less than the first thickness in a section between the first and second ends that forms a depression in the top surface; (2) a first lower magnetic pole part extending laterally from said first end to the ABS so as to be in alignment with a stitched magnetic pole part that overlies the first lower magnetic pole part; (3) an upper magnetic pole with an end at the ABS and that overlies a field coil, the upper magnetic pole connects with said primary lower magnetic pole through a back gap connection such that said depression lies between the back gap connection and the first end, and the depression has a back side that is closer to the ABS than the back gap connection; and (4) the stitched magnetic pole part extends downward from the upper magnetic pole along the ABS, the stitched magnetic pole part and lower magnetic pole part have a width at the ABS that defines a track width; (b) a layer of non-magnetic material between the stitched magnetic pole part and the first lower magnetic pole part, that forms a write gap; and (c) the field coil that is formed over, and insulated from, said primary lower magnetic pole.