A Novel Micro Heater Integrated on Flexible Polyimide Substrate With Fast Response and Uniform Temperature Distribution

This paper presents a novel micro heater prepared on polyimide thin film with fast response and ultra-uniform temperature distribution in the heating area. The transparent polyimide thin film was fabricated by spin-coating, baking and curing the liquid polyimide on the silicon wafer. A gold heater together with the vanadium oxide based thermistor was integrated on the polyimide thin film. Due to the low thermal conductivity of the polyimide thin film, the MEMS heater could reach high temperature with low power consumption and fast response time. FEA method was applied to optimize the shape of the gold heater to achieve uniform temperature distribution along the heating area. A copper island was also deposited on the back of the heater to improve the uniformity of the temperature distribution. The vanadium oxide based temperature sensor with a high temperature coefficient of resistivity as 2.4% was used for the temperature sensing. The temperature variation among the heating area is less than 0.2°C.