Publications
3D X-Ray ct analysis of solder joints in area array electronic package assemblies
The inability to do visual solder joint inspection has been a major road block to using advanced ICs with high I/O count in area array packaging technologies like flip-chip, Quad Flat No Lead (QFN) and Ball grid Arrays (BGAs). In this paper, we report the results of a study to evaluate 3D X-Ray Computed Tomography (3DXRay-CT) as a solder inspection technique for area array package assemblies. We have conducted an experiment with board assemblies having intentionally designed solder defects like cold solder joints, solder-mask defects, unfilled vias in solder pads, and different shape and size solder pads. We have demonstrated that 3D X-Ray-CT technique was able to detect all these defects. This technique is a valid technique to inspect solder joints in area array packaging technologies.