Faulty solder joint test method - using laser beam to generate ultrasonic signals which are sensor monitored

摘要

Solder joints between electronic component leads (2) and connection points on conductor plates (3) are tested by irradiating the joint with a laser beam which does not visibly affect the heated surface. The heating effect gives out an ultrasonic signal which passes through the joint and is detected by a sensor (4). The detected signal is compared with signals give off by previously well soldered joints and the quality of the joint ascertained. ADVANTAGE - Effective destruction-free testing method which is quick to carry out.