Measurement of thermo-mechanical deformations of wafer-level CSP assembly under thermal cycling condition

The understanding of thermal deformation has been recognized as the key for a reliable electronic packaging design. In this study, thermal deformations of Ultra CSP/sup TM/ 80 assembly during a thermal cycling were investigated using real-time high sensitivity moire interferometry. For temperature cycling, a small-sized thermal chamber having an optical window was developed. The nominal shear strain of solder joint and the warpage of the wafer-level CSP assembly were measured under a thermal cycle.