板壳状微电子器件的数字层析成像检测方法

Computed Laminography Imaging Inspection Method for Plate-Shell Microelectronic Devices

传统工业CT(industrial computed tomography,ICT)成像方法受扫描原理和探测器、射线源等硬件条件的限制,难以对芯片、印刷电路板等板、壳状微电子器件实施有效的数字层析成像检测.为此,讨论了一种基于锥束射线倾斜扫描和代数重建技术(Algebraic Reconstruction Technique,ART)的薄板层析成像(Computed Laminography,CL)方法,研究了其基于投影凸集理论的投影预处理方法及基于不同区域相似性的重建图像非局部平均降噪后处理方法,建立了基于非晶硅面阵探测器的实验系统,并完成了CPU芯片和印刷电路板的CL成像.实验结果证明了该方法的正确性.

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.