| 摘要 |
PURPOSE:To relieve mis-decision due to improper contactness of a probe by pressing the probe into contact with circuit terminals of a memory element, collating a waveform outputted from a detector of the element not written with a mgnetic bubble and discriminating the propriety of the contact. CONSTITUTION:The contact resistance is measured by pressing the probe into contact with the circuit terminals of the memory element. If the result of decision of a memory element is NO, the measurement is finished at the point of time and if it is OK, the characteristic test is executed. If the result of this test is OK, the element is evaluated as a non-defective element and if the result is NO, the sense waveform is checked. The waveform is checked by applying a strong bias magnetic field to the element so as to annihilate written magnetic bubbles or annihilating all the written magnetic bubbles by an annihilating device 6, thereby decides the disturbance of the sense waveform from a detector 3. If no disturbance exists in the element, the cause to defective memory is in the element itself and the element is evaluated as the defective element. If disturbance exists, the cause is improper contact of the probe and the test is executed again. |
