硅基红外热堆中热电偶尺寸和对数对探测性能的影响

Effects of Size and Number of Thermocouples on Device Performance in a Infrared Silicon Based Thermopile

分析了多晶硅 -金集成热堆中热电偶的尺寸和对数对热堆性能的影响 ,对非接触红外测温的实用型热堆提出了设计和改进的思路 .随着热电偶对数的增加 ,时间常数减小 ,响应率增大 ,探测率出现最大值 .减小热电偶的长度可以减小热堆内阻和时间常数 .多晶硅横截面积和金横截面积的比值接近最佳比值时 ,探测率呈最大值 3× 10 8cm· Hz1 / 2· W- 1 .

The size and number of thermocouples in a infrared silicon based thermopile device have much effect on the performance of the devices in the non contact infrared temperature measurement.The main parameters of a thermopile,such as responsivity,detectivity,total resistance and response time,vary according to the size and number of thermocouples.The guidelines for designing and improving for a practical device are presented on the basis of theoretical analysis.As the number of thermocouples increases,the responsivity increases,the response time decreases and there appears a maximum value of the detectivity.The resistance and response time can be reduced by shortening the length of the thermocouples.When the ratio of the size of cross section of silicon to that of the metal(gold or aluminum) one reaches the optimum value,the maximal detectivity of 3×10 8cm·Hz 1/2 ·W -1 is obtained.