新型薄膜热电变换器的误差分析及其设计制作

Study on the Thermoelectric Conversion Transfer Error and Fabrication Process of Novel Film Thermal Converter

交流电压(流)基准是国家交流电压(流)量值传递中的基准计量器具.首先分析新型薄膜热电变换器的热电转换误差,提出采用微桥谐振器非接触式测量加热电阻温度,属于新型薄膜热电变换器中加热电阻的高灵敏度温度检测方式、减小温度传感器与加热电阻之间的寄生电容、减小因热电效应、寄生电容和介质损耗引起的交直流转换误差,从而具有较高的测温灵敏度.其次研究新型薄膜热电变换器设计制作中的关键工艺,加热电阻辐射的热量使得微机械桥平均温度上升,轴向压应力增加(或拉应力减小),谐振频率减小,通过测量微桥谐振频率的变化获得加热器的温度信息,而温度测量元件从加热电阻汲取的热量极小.这种新型薄膜热电变换器的测量输出量为频率信号,受电路噪声影响很小,因此是一种高计量精度的薄膜热电转换器.

The study on the alternating voltage and current criterion is very important because it is national standard measuring instruments in quantity transmission of ahetnating voltage and current, and it is the foundation of alternating power and electrical energy measuring. The project put forwards a novel high sensitivity thin-film thermal converter based on a microbridge resonator to measure the temperature of heat resistor non-contact with the hope of reducing AC/DC conversion errors and parasitic capacitance between heat re- sistor and temperature sensors. Average temperature of microbridge is rised due to thermal radiation of heat resistors. Axial compress stress increases（ or tensile stress decrease） and the resonance frequency decreases with the temperature elevation, we can get information of the heat resistorg temperature by measuring the changes of the resonance frequency. This novel thin-film thermal converter have the adentages of high measuring sensitivity and precision, low AC/DC converting errors caused by thermoelectric effect, parasitic capacitance and dielectric loss. Heat absorbed by temperature measuring element in the novel thermal converter is negligible. Its output signal is frequency with negligible circuit noise, thereby it is expected to get an excellent thermoelectric converter with very high conversion accuracy.