No abstract

No abstract

No abstract

For surface mount technology, the occurrence of void defects inside solder balls during the ball grid array (BGA) reflow is an important problem. In this paper, we design a simple automated system for void detection. First, it can analyze the X-ray images obtained from arbitrary rotating angles and it is robust against occluded balls caused by some interference. Second, we apply the new method, which is to average multiple outputs of local contrast enhancement over different block sizes, for treating poor contrast images in order to reduce some false voids while the accuracy of void location and void area is reasonably preserved. These conclusions were confirmed by our experiments.

No abstract