Finite element and Monte Carlo modeling of the electrical and thermal properties of high areal density MR read-back heads

The current density distribution in magnetoresistive read-back heads with abutted permanent magnets was studied by using finite element modeling. The parasitic junction resistance was calculated as a function of reader width and stripe height. The Joule heat, which was generated by the local current density, was subsequently used as a heat source for a subsequent calculation of the local temperature rise in the active sensor area. The effect of the dispersion in reader width and stripe height on the average temperature rise was studied by Monte Carlo simulations. The thermal modeling predictions were in agreement with the experimental data from actual read-back heads. The thermal modeling was further used to study the trends in the bias current and voltage as a function of areal density.