ESD testing of GMR heads as a function of temperature

ESD testing of giant magnetoresistive (GMR) heads as a function of temperature is described. Two different GMR designs are subjected to HBM ESD step stress testing to failure over a range of temperatures. The designs tested are an IrMn GMR head and a PtMn GMR head. Results show that different designs of GMR heads produce significantly different failure trends as a function of temperature. The IrMn heads showed no significant reduction of either the magnetic or the resistive V/sub HBM/ failure points. These heads also exhibited a behavior termed "bias masking of pinned layer reversal". "Bias masking" occurred only beyond a certain substrate temperature, where the pinned layer reversals due to injected ESD transients were no longer visible. This may be due to the setting or resetting of the pinned layer by the bias current. The PtMn heads showed a clear reduction in both magnetic and resistive V/sub HBM/ points as a function of temperature. It is concluded that it is important and interesting to study the effects of temperature on the ESD behavior of GMR heads.