AlN微热板气体传感器阵列热失稳特性研究

Study on thermal instability characteristics of AlN micro-hotplate gas sensor array

采用微机电系统(MEMS)技术设计和制作了一种基于氮化铝(AlN)基陶瓷微热板2单元气体传感器阵列。传感器单元由加热器电极和信号电极组成,中间加热区周围通过激光微加工刻蚀有4个热隔离通孔以减少热传导损失,并通过4个梁与边缘相连接。利用ANSYS软件对传感器阵列热结构进行了热场耦合有限元仿真分析,验证了设计的合理性及工艺的可行性。通过热干扰测试分析得出,传感器单元1工作在300 mW时,加热温度为130.6℃,对另一单元产生的热干扰温度为119.1℃,两单元同时工作在300 mW时产生的热温差仅为3.9℃,两单元的热响应速率均为6 000 ms。可见,研究传感器稳态下单元之间的热干扰大小和瞬态下热平衡速率对集成传感器阵列热稳定性具有重要意义。

The AlN-based ceramic micro-hotplate two-unit gas sensor arrays were designed and fabricated using mi- cro-electro-mechanical system （MEMS） technique. The sensor unit consists of heating and signal electrodes, around its middle heating area, four thermal isolated holes were prepared with laser micro-processing etching to reduce the thermal conduction loss, which are connected with the edge through four beams. The thermal coupling field behavior of the sensor arrays was simulated and analyzed using the ANSYS software, which verifies the rationality of the design and the feasibility of the processing technology. The thermal interference test analysis results show that when the unit No. 1 of the sensor operates at 300 mW, the heating temperature is 130.6 ~C, and the thermal interference tempera- ture to the unit No. 2 is 119.1 ℃. However, when two sensor units operate simultaneously at 300 mW, their tempera- ture difference is only 3.9 ℃. The thermal response speeds of the two units are both 6 000 ms. Hence, it is of great significance to study the thermal interference behavior between the stable sensor units and the effects of transient thermal balance rate on the thermal stability of integrated sensor arrays.