Thermal Defomation Measurement of Electronic Devices, QFP and MCM, by Moire Interferometry, and Finite Element Analysis

Abstract

Thermal deformations of two electronic devices, QFP (Quad Flat Package), MCM (Multi chip Module), were measured by moire interferometry. A thermal loading was conducted by cooling the devices from an elevated temperature 100°C to room temperature 25°C. Moiré fringes were obtained on the cross sections of the devices to clarify the effect of the CTE (Coefficient of Thermal Expansion) mismatch of the micro components, such as silicon, metal and resin. The experiments were also made using QFP mounted on the PCB (Printed Circuit Board) to examine the influence of the PCB. FEA (Finite Element Analysis) was also performed to simulate the thermal deformations of the devices.