Transient Thermo-Resistance Apparatus for Nondestructive Monitoring of the Thermal Integrity of Magnetoresistive Heads
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
Apparatus is described for nondestructively testing the thermal properties of a magnetoresistive (MR) sensor by transient thermo-resistance detection. The test apparatus comprises a pulsed laser 1, the output beam of which is focused by a lens 2 having a focal length L. The MR sensor 3 under test is mounted on a slider body 4 which is positioned within the path of the laser beam at a distance x from lens 2 which is less than the focal length L. The pulsed energy from laser 1 causes a resistance change in the MR element and this change is sensed over twisted leads 10 in a circuit that includes a battery 5 and resistors 6 and 7. The resistance changes are monitored across resistor 7 by means of a digital voltmeter 8 and an oscilloscope 9.