传统的电容式湿度传感器采用感湿膜都是水蒸汽通过上表面扩散的长方体感湿膜,因上表面面积有限,且有一部分被上电极覆盖,影响了系统的响应时间。采用了水蒸汽从周围扩散的圆柱体、圆环体结构,将其与传统的长方体做了比较,并在分析圆环体时引入的占空因子k,最后,将电容归一化得出圆柱体的响应时间约为长方体的10倍,圆环体与圆柱体相比,响应时间可减少约77.2%,大大缩短了响应时间,且圆柱体与圆环体对与薄膜厚度没有特别要求,因而还可以减小器件体积。
The convertional shape of thin film for capacitive humidity sensor is rectangular body,yet it can effect the response time for its limited upper area and some part covered by upper electrode. Cylindrical and cirque body structure is introduced, admiting vapour enteting from circumambience. The fill favtor k is introduced here to explain the cirque body. Normalize the capacitance and find the response time of cirque body is 10 times faster than rectangular body and the cirque body can deminish 77.2 % for cylindrical body, furthermore, the cylindrical and cirque body havn' t request for thickness of the film, which can minish the bulk.