A Feasibility Study of Using X-Ray Computer Tomography for Ball Grid Array (BGA) Inspection

It is of interest to study the feasibility of using computing tomography technique on BGA inspection. The effects of system parameters on the quality of the reconstructed images were studied first. The system parameters studied are projection type, projection number, sensor number, and filter. For fan beam projection, there are two additional parameters are studied. They are the fan beam arc angle and the sensor geometry. It was found that the increase in projection number and sensor number generally improve the quality of reconstructed image. The effects of sensor geometry and the fan beam arc angle are not significant. BGA simulation test show the feasibility of using this technique to detect the shape and location of defects inside the BGA.