Detection Resolution Analysis of Scanning Acoustic Microscopy Used in Electronic Packaging

Abstract

Scanning Acoustic Microscopy (SAM) has been a powerful non-destructive testing tool used in electronic packaging and material characterization. With the development of 3D electronic packaging, internal dimensions of electronic packaging are getting more and more smaller, and the detection accuracy of existing non-destructive testing technology is far behind the requirements of manufacturing technology. In this study, a set of practical SAM system was developed independently by our Lab. And its detection resolution was analyzed using high frequency focused transducers with center frequency ranging from 20 MHz to 100MHz. The experimental results show that the lateral resolution of the ultrasonic transducer with 100MHz central frequency can reach about 40 microns, which is consistent with calculated resolution. Comparing with Sparrow criteria, Rayleigh criteria is more coherent with the experimental results.