Current-perpendicular-to-the-plane (cpp) magnetoresistive sensor with impedance adjustment

Abstract

A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) read head structure has the MR read head located between first and second shields (S, S) on a substrate with a shunt resistor Rconnecting Sto the substrate and a shunt resistor Rconnecting Sto the substrate, with Rand Rbeing approximately equal. Because Rand Rare close enough in value there is no significant interference pickup in the low frequency region. The shunt resistors can be formed from high-resistivity metal nitrides or cermets. The spacing between the substrate and Smay be selected to make the capacitance between Sand the substrate approximately equal to the capacitance between Sand the substrate to substantially reduce interference pickup in the high frequency region. Equalization conductors (EC, EC) may be connected to the substrate and spaced from Sand S, respectively, by electrically insulating material to create additional capacitances with values selected to substantially equalize the total parasitic capacitance on Swith the total parasitic capacitance on S