Visualization of Residual Thermal Strain Distribution for Underfill by Sampling Moiré Method

Abstract

  This paper presents a method for visualizing the distribution of residual thermal strain for underfill (UF) materials using the sampling moiré method to evaluate the internal thermal deformation of semiconductor components. In this method, microgrids are formed in advance on the sample surface at room temperature, and the residual thermal strain distribution can be measured at any temperature relative to the sample formation temperature. A heating chamber for flip chip package (FCPKG) was designed under a laser microscope, and the developed method was used to measure and compare the residual thermal strain distribution at 150℃ in FCPKG of two types of UF with different glass transition temperature (Tg) Experimental results of residual thermal strain distribution are reported.