Development of Inspection System for IC Lead Frame Defects
Hirokazu Tsuji and Kazuo Maruyama
Precision and Intelligence Laboratory, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 227, Japan
A visual inspection system for IC lead frame defects based on the image processing technique is developed, and its inspection algorithm for the practical use is discussed. The inspection system consists of an image input system using a microscope and a TV camera, an image processing system, and a lead frame carrier. The inspection algorithm to recognize defects consists of pattern matching and local feature extraction. In the pattern matching method, minimum recognition size of defects is limited to the positioning error of the lead frame; therefore, small defects are recognized by the local feature extraction method in which local irregular patterns are detected using logical filter.