Development and instrumentation of an integrated three–dimensional optical testing system for application in integrated circuit packaging

Measurement of hygrothermomechanical deformation is critical for the failure analysis and reliability evaluation of integrated circuit (IC) packages. Conventional methods, however, provide one– or two–dimensional measurements, and these measurements are not enough for accurate analysis and evaluation in many cases. In this paper, the development of a compact three-dimensional (3D) optical testing system based on moiré interferometry and Twyman-Green interferometry is described. Furthermore, a novel technique to simultaneously record the fringe patterns of three deformation fields with a single CCD camera is developed based on this 3D testing system. Some well-established measurement methods like thermal-mechanical-analyzer (TMA) and Taylor-Hobson stylus profilometer are used to verify the system performance. The results show good comparisons. In general, hygrothermomechanical deformation of IC packages during their fabrication and service can be measured comprehensively and dynamically using our 3D optical testing system, some drawbacks of the conventional optical methods and/or systems in the application of the IC packaging are overcome.