The Thermal Analysis Of Electrothermal MEMS Micromirror Based On Bimorph Actuator

The micro-electro- mechanical systems(MEMS) is a cutting-edge technology that combines mechanical, optical, electrical, magnetic technology by the integrated circuit technology and the micro mechanical processing technology. With the characteristics of low power consumption, small size, high integration, high sensitivity and low price, MEMS has been widely applied to biomedicine, automotive industry, military products and aerospace fields. Electrothermal MEMS Micromirror is a light modulator which can adjust the spatial distribution of the incident light with movement and deflection of micromirror driven by the micro actuator, and has been widely used in communication field. But with the thermal driving mode, Electrothermal MEMS Micromirror will be affected by heat, which makes it necessary to do the thermal analysis.In this paper, the thermal analysis of electrothermal MEMS micromirror is studied with three parts, namely the temperature distribution of bimorph actuator, the crosstalk of drive actuator arms and substrate temperature. The first part puts forward two methods to decouple and solve the bimorph actuator’s power distribution and temperature distribution based on its thermal resistance model, and presents an estimation method for bimorph structure’s convection coefficient by making the bimorph average temperature as the reference index. The second part studies the crosstalk of a micromirror which having four actuating arms. According to the heat source location in bimorph structure, this paper puts forward different crosstalk models and analyzes the relationship between driving arm temperature and their parameters, which provides support to find feasible suggestions to improve bimorph temperature and reduce the thermal crosstalk. In the last part, making the MEMS micromirror as the research object,in whose substrate embedded a resistance acting as the temperature sensor, this paper establishes its TO package mode l and analyze s substrate static temperature and temperature response, which provides support to improve substrate temperature response speed and keep substrate temperature constant.Through modeling, theory analysis, simulation and test, the thermal analysis of the electrothermal MEMS micromirror becomes clear and complete, which enriches the research of electrothermal MEMS micromirror in thermal field and has important value for design and applications of electrothermal MEMS micromirror.