IC solder joint inspection based on the Gaussian mixture model

Purpose This paper aims to inspect solder joint defects of integrated circuit (IC) components on printed circuit boards. Here, an IC solder joint inspection algorithm is developed based on a Gaussian mixture model (GMM). Design/methodology/approach First, the authors train a GMM using numerous qualified IC solder joints. Then, the authors compare the IC solder joint images with the trained model to inspect the potential defects. Finally, the authors introduce a frequency map and define a metric termed as normalized defect degree to evaluate qualities of the tested IC solder joints. Findings Experimental results indicate that the proposed method is superior to the state-of-the-art methods on IC solder joint inspection. Originality/value The approach is a promising method for IC solder joint inspection, which is quite different from the traditional classifier-based methods.