Imaging of packaging-related problems in electronic components by scanning acoustic microscopy

Low-frequency (50 MHz) scanning acoustic microscopy has been applied to the problem of imaging defects in semiconductor packages. The results have been compared with the more established technique of X-ray shadow imaging. The scanning acoustic microscope has been found to be able to image a greater variety of defects than X-ray shadow imaging, although the acoustic image could often only be fully interpreted after comparison with the corresponding X-ray image. Scanning acoustic microscopy is now proving to be a valuable analysis technique for the detection and characterisation of packaging related problems.