| 摘要 |
PURPOSE:To inspect accurately the state of wire bonds. CONSTITUTION:An ultrasonic signal generated from an ultrasonic oscillating circuit 32 is supplied to an ultrasonic vibrator 26 via an output transformer 34. The current flowing through the ultrasonic vibrator 26 is converted into a voltage by a resistor 37, and the voltage is fed to a waveform shaping circuit 35. In the circuit 35, the phases of the current flowing through the vibrator 26 and the ultrasonic signal generated from the ultrasonic oscillating circuit 32 are sensed respectively, and these phase data are brought to a frequency counter 31 via a PLL 38, and as a result, such a control that the phases of the forgoing current and the foregoing ultrasonic signal are forced to coincide with each other is performed. By a CPU 30, the frequency of the ultrasonic signal is sensed at least one time during a wire bonding, and when the sensed frequency continues to be present in the range other than a predetermined one or is present in the range other than the predetermined one by the times not less than predetermined set times, the wire bonding is recognized as a faulty one. |
