A New IC Solder Joint Inspection Method for an Automatic Optical Inspection System Based on an Improved Visual Background Extraction Algorithm

In the field of automatic optical inspection (AOI), defect recognition for an integrated circuit (IC) solder joint is a long-standing task. Inspired by a visual background extraction (ViBe) algorithm, an object detection method in computer vision, we propose a new inspection method for IC solder joints with an improved ViBe algorithm. To the best of our knowledge, we are the first to consider the defect inspection problem as an object detection problem. We build a solder joint model using the ViBe model updating scheme. Then, we compare the solder joint image with the well-trained model to detect potential defects. Finally, we introduce a frequency map method and define a metric named defect degree to evaluate the qualities of the solder joints. Experimental results show that our method is universal, accurate, and easily debugged compared with the other existing methods.