What can my x-ray inspection system tell me about the levels of voiding within BGAs?

The greater greyscale sensitivity that digital x-ray inspection systems provide allow a far more subtle investigation into joint quality, especially of BGAs. For example, they are able to interrogate the joint interfaces of a BGA far better and indicate the presence of interfacial voiding within the solder balls in addition to bulk, or process, voiding. Further information on the different types of voiding that can be seen using digital x-ray inspection systems can be found in the following technical paper presented by Dage at the Proceedings of SMTA International, Chicago, September, 2004 - Use Of Digital Imaging As A Process Control Tool