A three-dimensional sensor for automatic visual inspection of soldered parts

A high-speed three-dimensional (3-D) sensor has been developed for the automatic visual inspection of soldered parts on printed circuit boards. Its advantages over existing techniques include the detection of the 3-D shape of objects with high speed and high accuracy. Using a coded fiber-optic array and a high-speed processing unit for detecting the position of the scanning light spot, the 3-D sensor is capable of obtaining 9-b range data and 7-b brightness data for 1024×1024 points within 0.85 s. An inspection system using the 3-D sensor can precisely detect the shape of solder joints and the locations of parts, and it can judge them to be good or defective