| 摘要 |
PURPOSE:To perform a test while the heat generating state of an element due to back drive is directly monitored, by allowing a constant current to flow to the protective diode in a logical element to be tested and comparing the voltage between both terminals of the diode with a reference signal. CONSTITUTION:The logical element 19 to be tested mounted on a substrate 20 is connected to a digital in-circuit tester 21 through the test pins 8-11 of a test fixture 18. The receiver 1 and driver 2 of the in-circuit tester 21 are respectively connected to the pins 8, 9 connected to both terminals of a gate to be tested to perform a test. A constant current source 5, a voltmeter 6 and a comparator 7 are connected to the pins 10, 11 connected to both terminals of the protective diode 15 of the other gate 14 and the forward direction voltage of the protective diode 15 is monitored and an alarm is outputted to a main control part 17 when the forward direction voltage reaches a predetermined value or less by heating due to back drive. |
