Reliability analysis in microelectronic packaging by acoustic microscopy

Acoustic microscopy has developed towards an acknowledged technique in nondestructive testing of different assemblies in microelectronic packaging. Beside the standard investigation of ICs within plastic packages or under-fill structures of flip chips and CSPs, excellent results could be reached in investigating heat sink connections, power modules with direct copper bonding as well as wafer bonding applications. A brief presentation of the measurement principle and setup including the different modi of investigation is completed by selective examples of industrial application. Practical experiences concerning the possibilities and limits of this testing method are discussed