一种微型Pt温度传感器及其读出电路的研究

基于电阻温度系数(TCR)原理及微机电系统技术,设计并制作了一种用于微型聚合酶链式反应(PCR)芯片的Pt温度传感器及其读出电路。利用溅射和剥离技术将厚度为100 nm的弯曲条形Pt传感器制作在硅衬底上。其长度和宽度分别为2 030μm和10μm。设计了基于四线法温度测量的读出电路,该电路主要包括一个恒流源电路和一个电压放大电路。测试结果表明,该传感器的电阻温度系数为1.48×10-3℃-1,其电阻变化随着温度的变化具有良好的线性度,当温度在27～100℃变化时,电阻范围在653.5～716.5Ω变化。在接出一个8位的模数转换器以后,整个传感器和读出电路能确保一个精度为0.2℃的温度控制,满足一般PCR测量需要。

Research on Micro-Pt Temperature Sensor and Its Read-Out Circuit

Pt temperature sensor and its read-out circuit used for micro polymerase reaction(PCR) chip,were designed and realized based on the temperature coefficient of resistance(TCR) principle and modern MEMS technologies.The turn strip shape Pt temperature sensor with thickness of 100 nm was fabricated on silicon substrate by sputtering and lift-off process.Its total length and width are 2 030 μm and 10 μm respectively.The temperature reading-out circuit was designed based on four-wires method,which included a constant flow source circuit and a voltage amplifier circuit.The test results show that the TCR of obtained Pt resistor is 1.48×10-3 ℃-1 and its resistance changes presented a good linearity with the temperature variation,and its resistance changes from 653.5Ω to 716.5 Ω when the temperature changes from 27 ℃ to 100 ℃.With an 8 bits A/D converter,the measurement assures an accuracy of 0.2 ℃ temperature controlling,which can meet a common PCR requirement.