MEMS infrared light source stress optimization and reliable package design.

Abstract

Aiming at the effects caused by stress and deformation on Micro-Electro-Mechanical System (MEMS) sensors, the stress distribution in the radiation area of the MEMS infrared light source is investigated, and by simulating and optimizing the thickness of the composite support film of the chip structure in COMSOL, a film layer thickness matching with lower stress and deformation for the MEMS infrared light source is derived. The utilization of the particle swarm algorithm and backpropagation neural network model allowed for the optimization of simulation data, enabling regression prediction over a broader range of thicknesses and providing a more precise depiction of the stress distribution trend. In addition, the specifications of the MEMS device help us to analyze the design of the support film thickness in the processing of the residual stress within the controllable range. To ensure the long-term stability and functionality of MEMS infrared light source chips in harsh environments, a comprehensive set of packaging schemes has been devised. Through simulations, it has been demonstrated that these packaging schemes effectively enhance the thermal efficiency of the light source while mitigating thermal stress and deformation that may arise during its operation. Consequently, this packaged configuration proves to be more advantageous for the sensor's normal operation under challenging conditions such as rain and temperature fluctuations, as compared to utilizing a bare chip. Finally, the manufacturing flow and layout design for the MEMS infrared light source chip are provided to guide the process of chip fabrication.