An automatic inspection system for printed wiring board masks

摘要

This paper describes an automatic inspection system for printed wiring board masks. This system utilizes a hierarchical defect detection algorithm developed for inspecting high precision mask patterns for both printed wiring boards and integrated circuits. This algorithm makes use of geometrical characteristics of mask patterns to discriminate defects. Sufficient defect detection capability, as well as high inspection throughput, has been accomplished by hardware-implementation of the algorithm and inspection result utilization through retouching machines.