Computed laminography imaging inspection method for plate-shell microelectronic devices

Limited by the scan principle and the hardware such as detectors and X-ray sources, conventional industrial computed tomography (ICT) can not execute the effective tomography imaging of plate-shell microelectronic devices. In order to realize the tomography imaging of this kind of microelectronic device, a method called computed laminography (CL) has been researched. It is based on the cone-beam X-ray tilt scan and the algebraic reconstruction technique (ART). The projection pre-processing method based on the projection convex on sets (POCS) and the non-local means post-processing method based on the similarity between different regions have been discussed. An experiment system based on a-si flat panel detector has been developed. The CL imaging experiments of CPU chip and printed circuit board have been executed successfully. The validity of this method was verified by the results of experiments.