Thermal Strain Measurement on Electronic Packages Using Digital Image Correlation Method

Abstract

An effective strain measurement system for small region in electronic packages using digital image correlation method (DICM) was developed. The accuracy of measurement using the DICM was affected by the distortion of captured images. An error correction method using a piezo-stage was proposed to improve the accuracy of the DICM. The measured distribution of thermal strain in a print circuit board accurately correlated to the macroscopic warpage measured by a laser displacement meter. It proved the accuracy of the measured strain. The distributions of thermal strain in chip embedded print circuit boards were measured using the DICM. The measured distributions of strain qualitatively corresponded with those calculated by the finite element method.