Characterization of MEMS Inertial Measurement Unit Package with Digital Image Correlation

Abstract

In the field of MEMS and sensors, package has also to allow the ‘sensing’ of external ambient without influence the measurement of the target physical quantity. It follows that package plays a primary role since it may strongly affects the device behavior and performance. Depending on the application and mission profile, design and package technology need to be targeted in order to fit the best the given requirements.

Ceramic cavity packages limit the stress transfer to the MEMS due to the high mechanical stiffness and to the coefficient of thermal expansion that can be considered matched versus that of silicon sensor ensuring high performance in terms of stability. On the opposite the thermomechanical parameter of ceramic are in discrepancy with the one of PCB and this lead to a higher stress on the solder joint between component and board.

In this paper it is presented a package structure that has the target to achieve the best tradeoff between device stability and reliability requirements. The introduction of a Silicon Interposer add a degree of freedom to the structure allowing the possibility for an optimal material and design.

Numerical analysis has been performed to properly design the package. Correlation with a study on full device with field displacement characterization technique based on digital image correlation (DIC) is demonstrated.