| 摘要 |
PROBLEM TO BE SOLVED: To nondestructively discriminate the joining states of minute junctions of electronic parts from the reflected waves of ultrasonic waves transmitted to the junctions. SOLUTION: An ultrasonic pulse transmitted from an ultrasonic oscillator 3 is transmitted to the junction of electronic parts through an electronic parts joining tool 4, and ultrasonic waves reflected from the tool 4 are received. Then the difference between the peak output voltage of the detected waveform and amplitude obtained by converting the received ultrasonic waves, and the peak output voltage of the detected waveform and amplitude of ultrasonic waves reflected from the tool 4 measured while the tool 4 is not in contact with the junction before joining the junction, is computed. Thereafter, the computed difference is compared with a curve indicating the relation between the voltage difference and peel strength, and the peel strength of the junction is estimated from the deviation of the computed difference from the curve. |
