Stress-minimized packaging of inertial sensors using wire bonding

This paper presents a packaging approach for inertial sensors using wire bonding technology. The die is mounted exclusively by bond wires on the front- and backside to the package. Conventional single-side die attach to substrates, such as gluing, is abandoned. The approach is characterized by its novel and symmetric die attach concept as well as its simplicity of applying a standard wire bonding process. The wire bond attachment facilitates significant reduction of thermally induced mechanical stresses. The attachment concept is characterized in terms of attachment stiffness and potential die resonances using Laser Doppler Vibrometry (LDV). White-light interferometry is used to investigate stress related warping that is induced by the die attachment process.