Thermal Displacement and Strain Fields Measurement of Electronic Package, Stacked-MCP, by Phase-Shifting Moiré Interferometry Using Wedged Glass Plate

Abstract

The thermal deformations of electronic package, Stacked-MCP (Multi Chip Package), were measured by phase-shifting moiré interferometry. This technique was developed using a wedged glass plate as a phase shifter to obtain the displacement fields with the sensitivity of 30nm/line. Digital image processing was also introduced to determine the thermal strain distributions quantitatively in the whole observation areas. Thermal loading was applied from room temperature 25°C to two states of elevated temperature 75°C and 100°C. The thermal strains were then investigated with the two states. The results showed that the normal strains concentrated around the two silicon chips. And concentration of the shear strain occurred at the end of the lower chip.