| 摘要 |
PURPOSE:To enable simultaneous measurements of wetting of both the following by a method wherein the difference in input waveform of a light emitting diode and in output waveform of a photo transistor is detected with the quality of mount wetting. CONSTITUTION:A voltage waveform is impressed from a pulse input part 3 onto the light emitting diode 1. At this time, the value of forward voltages VF1 and VF2 of the diode 1 are read out, and kept held in a measurement value holding part 6. The value of the forward voltage VF can obtain the VF1 value at the time of no heat-generation of elements and the VF2 value at the time of VF decrease due to heat generation. The better is the mount wetting, the earlier recovers this VF2 to the value of VF1, therefore, the quality of mount wetting can be judged by the value of VF2 after the set time. On the other hand, the photo transistor 2 acts and varies waveforms at the point 0, which vary with mount wetting. V1 and V2 are obtained at every point of the waveform inclined by wetting and are held in the measurement value holding part 8, then, the voltage value held finally is calculated by testers, resulting in the judgement of mount wetting. |
