This paper describes the detection capability of micro delamination in ICs according to the transducer frequency of SAM (Scanning Acoustic Microscopy) equipment through a case study of non-destructive failure analysis. The analysis of scanning acoustic microscopy is non-destructive, but is difficult to define micro de-lamination or micro crack. In this study, two SAM systems and various transducer frequencies were used to detect micro de-lamination on the lead finger area. In the results of non-destructive analysis by utilizing two systems, one SAM detected the micro delamination but the other SAM did not define micro delamination with C-scan mode. To confirm an accurate delamination phenomenon, we analyze the destructive analysis under cross-sectional inspection and the micro de-lamination was observed. The cause of non-detection for micro delamination is not due to the difference between equipments, but due to the transducer frequency. This paper will be concluded with a discussion on what kind of transducer frequency are selected according to distance from package surface to chip surface, package materials, and micro de-lamination thickness.