Patent ID: 8225486

Claim:
A method of manufacturing a perpendicular magnetic recording head comprising: a main pole having a flare point at which a width in a cross-track direction begins to increase, wherein a width of a portion of the main pole is constant in the cross-track direction from the flare point to an air bearing surface; a return pole being magnetically coupled with the main pole at a side opposite to the air bearing surface; and a coil interlinked with a magnetic circuit comprised of the main pole and the return pole, wherein the magnetic recording head is formed by: forming a plurality of head elements on a wafer, each head element comprising: the return pole, the coil, and the main pole; cutting the wafer into respective head elements so that individual head sliders are formed; calculating a ratio of an amplitude of an electrical signal applied to the coil of the write head on the head slider to an amplitude of output from an independent magnetic field sensor not embedded in the head slider, wherein the independent magnetic field sensor is disposed near the main pole so as to be opposed to the main pole across the air bearing surface, wherein the ratio is calculated while a displacement between the main pole and the magnetic field sensor is swept; and determining a flare point height of the main pole from the calculated amplitude ratio.