One of the most important issues whether unisotropic conductive film (ACF) interconnection technology is suitable to be used for flip chip on organic board applications is formations and warpages of thermal cycling reliability. In this study thermally induced deformations and warpages of ACF flip chip assemblies as a function of distance from neutral point (DNP) and ACF materials properties were investigated using in situ high sensitivity moire interferometry. For a nondestructive failure analysis, scanning acoustic microscopy investigation was performed for tested assemblies. To elucidate the effects of ACF material properties and DNP on the thermal cycling reliability of ACF assembly. Weibull analysis for the lifetime estimation of ACF joint was performed, unit compared with thermal deformations of ACF flip chip assembly investigated by moire interferometry, Results indicate that the properties of ACF have a significant role in the thermal deformation and reliability performance during thermal cycling testing. Therefore, optimized ACF properties can enhance ACF package reliability during thermal cycling regime.