用于高空气象探测的聚酰亚胺薄膜湿敏电容研究

设计制作了一种基于MEMS技术,可应用于高空湿度探测的薄膜湿敏电容.电容采用三明治结构,聚酰亚胺薄膜作为湿度敏感层材料,金作为上、下电极.测试结果表明,在15%RH~95%RH的全量程范围内,湿敏电容的合格率≥80%,灵敏度约为0.29pF/%RH,线性误差<1.5%RH,湿滞较小,响应时间小于4 s,温度系数好,具有良好的长期稳定性.研究表明,制作的湿敏电容综合指标良好,适合批量生产,可以满足高空气象探测要求.

Study on polyimide film humidity sensitive capacitor for high altitude meteorological observation

Based on MEMS technology, a design of humidity sensitive
capacitor was described. The capacitor employed sandwich structure,
i.e. polyimide was used as the humidity sensitive material and gold
was used as the electrodes. Capacitor shows a good pass rate of
80{\%}. As can be seen from the measurements, over the testing range
from 15{\%} RH to 95{\%} RH, the maximum linearity error is 1.5{\%}
RH. The sensitivity reaches 0.29pF /{\%} RH. The hysteresis is
small, and the sensor has fast response time of 4~s. Meanwhile,
capacitor shows good temperature coefficient and long-term
stability. The results show that the comprehensive indexes of
humidity capacitor are satisfactory. The capacitor is suitable for
batch fabrication and can be used for high altitude meteorological
observation.