陶瓷微板热隔离气体传感器阵列热干扰分析

Thermalinterference analysis of ceramic micro-plate thermal-isolated gas sensor arrays

热干扰特性是影响微热板气体传感器阵列热结构设计的重要因素之一。为探讨微热板阵列传感器单元之间的热力学特性关系,设计并制备了具有独立式加热功能的热隔离结构4单元微热板气体阵列,传感器阵列单元由Al N陶瓷衬底、Pt膜电极组成,为提高加热效率,阵列单元中间加热区采用激光微加工刻蚀热隔离通孔设计,与边缘形成微梁连接结构。利用有限元法对传感器阵列结构进行了热干扰仿真分析,验证了热隔离结构设计的合理性。给出了4种热干扰测试模式,并进行了热干扰特性测试分析,给出了4单元之间的热干扰规律曲线,得出传感器单元功耗300m W时最大干扰温度达169.6℃,最小热干扰温度84.7℃。热隔离通孔设计可有效降低传感器单元热传导损耗,热干扰分析对微热板传感器阵列的热结构设计具有重要意义。

Thermal interference characteristic is one of important factors influencing the thermal structure design of micro-hotplate gas sensor array. In order to investigate the thermodynamic characteristic of micro-hotplate array sensor units,the four-unit micro-hotplate gas sensor array with thermal isolation structure is designed and fabricated,which provides an independent heating function. The sensor array unit consists of Al N ceramic substrate and Pt electrodes. Thermal isolated holes are prepared in the middle heating area of sensor array units using the laser micromachining technology in order to enhance the heating efficiency. The thermal interference simulation analysis of sensor array structure is conducted with the finite element method. The result shows that the design of thermal isolation structure for sensor array is practical. Four kinds of thermal interference modes are provided,and then the thermal interference characteristics are conducted. Thermal interference curves of four-unit array are finally obtained. Experimental results show that when the unit power consumption is 300 m W,the maximum and minimum interference temperatures are about 169. 6℃ and 84. 7℃,respectively. The thermal conduction loss of sensor unit can be effectively reduced by employing the thermal isolation holes,and the thermal interference analysis is of great importance to the structural design of micro-hotplate sensor array.