ESD induced pinned layer reversal in spin-valve GMR heads

Magnetization direction of the pinned layer in the Spin-Valve giant magnetoresistive (SV) heads has been found to be reversed easily by electrostatic discharge (ESD). Thermal stress and magnetic field from ESD cause this phenomenon. This phenomenon happens only when the bias field direction by ESD current Is opposite to the magnetization of the pinned layer. The energy of magnetization reversal of the pinned layer from ESD is found to be a quarter of the ESD breakdown energy. For SV heads which consist of an AF film with higher blocking temperature, the energy becomes higher.