Optical inspection devices for looking at the balls of BGA are becoming more prevalent. How do these devices and conventional xray fit together as complemtary tools in the day-to-day product environment?
Dave; See my answer to "Alternate to X-ray" The combination of endoscope optical inspection with x-ray inspection provides the most effective means of BGA inspection. Transmission x-ray provides a very rapid means of qualifying then process control of reflow. When suspicious "signatures" are observed in the ball bond image pattern, then endoscopic inspection is indicated.