Acoustic microscopy reveals IC packaging hidden defects

Abstract

This paper highlights the possibilities of non-destructive techniques such as high frequency ultrasonic to find internal defects and discontinuities in plastic-packaged IC's. C-scan, B-scan, through-scan and signal polarity techniques were employed. These methods can complement each other in enhancing the interpretation of the scanning images. Case studies of detecting delamination between layers, porosity's, disbonds, pop-corn effect and even die crack when they are well oriented towards the ultrasonic beam will be presented in this paper. In addition, electrical overstress causing localized carbonized mold compound at bond wires and/or melted metallization on the die surface can be detected.