Non-Intrusive 3-D Image Inspection of Multi-layer Printed Circuit Boards and Electronic Devices

This proposal describes an approach for a non-invasive system of inspection that capitalizes on the advancing technology of three dimensional (3D) digital X-ray laminography and digital tomosynthesis in providing an automatic and non-destructive means of inspection for a device under test while allowing for high fault coverage of all pins. Newly available ultra-high resolution X-ray system technology offers solutions to detect and analyze failures down to micron levels, revealing many defects including IC, transistor or diode internal opens and shorts, capacitor plating deformations, open or shorted solder joints, lifted leads, missing solder balls or bridging between solder balls, holes in solder, component misregistration, IC tombstoning, voiding, and unacceptable size variations in solder bumps, as in BGA components. Such testing and inspection systems have proven to be a vital inspection tool for catching faults in printed circuit boards previously determined to be undetectable. We envision a completely automated X-ray inspection system, capable of handling all motion control, image acquisition, image reconstruction, and image analysis tasks. Also, new generation X-ray emitters exhibit very low power output, virtually eliminating the risk of damage to electrical and electronic devices.