Double wavelength combined electronic speckle pattern interferometry–moiré system for full-field strain analysis on electronic components

Determination of thermal dissipation capability and thermomechanical behavior of electronic components is becoming a relevant topic in view of the fact that thermal management can strongly affect reliability and lifetime of the component. The level of miniaturization, which is achieved in current electronics, requires that no-contact analysis must be privileged in view of the fact that any contact with the chip can significantly alter the heat capacity of the component and to introduce a systematic bias in the measurements. Moreover, the high complexity of electronics components suggests that full-field methods should be adopted in order to take into account about differences in terms of thermomechanical response in different areas of the same sample. In this article, an original optical set-up including a speckle interferometer and a projection moiré branch was developed; this system comprises two different laser sources emitting at two different wavelengths. Recording by a color camera allows detecting simultaneously the speckle pattern and the projected fringes. The whole information is successively separated in the post-processing stage and this allows obtaining in-plane and out-of-plane displacement fields. The system demonstrated its capability to determine dynamic response of the LM1084 analyzed component and, moreover, to detect the presence of a functional damage.