The Technology Of The Detection For Defects In BGA Package Based On Flat Panel Detector

The performance and assembly of BGA package is better than conventional components, but many manufacturers are still reluctant to invest in the development of high-volume production capacity of BGA package. Mainly because it is difficult to test the BGA package solder joints and ensure its quality and reliability. In this paper, the technology of BGA defect detection is studied systematically. The main contents include:1. We studied the algorithm of multi-level combined filter based on the edge detection of entropy operator and the fuzzy enhancement algorithm based on the sinusoidal membership function for the low contrast and fuzzy edge of BGA-ray images. Those algorithms can filter out the interference of image, clear the pictures, without undermining the useful information of image such as contour and edge.2. The segmentation algorithms based on edge detection and region are discussed, in order to extract defect features effectively. We segment images with the two combined algorithms that the image segmentation algorithm of fuzzy C-means clustering is used in the region of gentle the gray-scale transformation and the image segmentation algorithm based on edge detection is used in the area of severe gray-scale transformation. This algorithm highlights the small defects in the ball, and avoids over-segmentation of the region.3. Studied the algorithm of the extraction of ball eigenvalue, summed up the method to judge a variety of defects, then, identified the defects of BGA automatically according to BGA defect identification flow chart.