DETECTING DAMAGED TMR SENSORS USING BIAS CURRENTS AND OUTLIERS

• Main Authors: Paniagua, Guillermo Francisco, Iben, Icko E.T
• Format: Patent
• Language: English
• Published: 10.12.2020
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

A computer-implemented method to detect a damaged tunneling magnetoresistance (TMR) sensor includes applying current at at least two different current values to the TMR sensor and measuring a resistance, RTMR, at each current value. The method also includes measuring a slope in resistance vs. bias current, RDSLP, using the measured resistances RTMR and the at least two different current values. The method includes calculating a ΔRDSLP value as a difference between the RDSLP value and an expected value, RDSLP-expected, for the TMR sensor. The method includes determining whether the ΔRDSLP value is within a predefined range. In response to determining that the ΔRDSLP value is outside the predefined range, the method includes outputting an indication that the TMR sensor fails. In response to determining that the ΔRDSLP value is within the predefined range, the method includes outputting an indication that the TMR sensor passes.