具有SiO_2绝缘层的硅基聚酰亚胺电容式湿度传感器的特性研究

Properties of the Polyimide Capacitive-type Humidity Sensor Based on Si Substrate with a SiO_2 Insulation Layer

传统夹层聚酰亚胺电容式湿度传感器在亚胺化过程中感湿膜会因挥发物产生微孔,对这种传感器的成品率造成很大影响。为此,从元件的结构入手,制作Si-SiO2-PI结构的湿度传感器,对该种传感器的特性进行了测试,并与传统夹层式结构的样品进行了对比。研究表明,Si-SiO2-PI结构的湿度传感器在同等测试条件下,其电容值要比传统结构样品高25%,湿度灵敏度达到1.24 pF / %,具有重复性好和一致性高的优点,并且特别利于克服薄膜孔洞和厚度不均匀造成的短路现象,有利于批量生产。

The yield of the traditional sandwich-type sensor is badly influenced by the micro holes in the film caused by the by-products of the imidization reaction. The Capacitive-type humidity sensors with Si-SiO2-PI structure were prepared and the properties were studied. The properties were compared with those of the traditional sandwich-type sensor. The results showed that the capacitance is increased by 25%; the sensitivity reaches 1.24 pF/%. Short circuit caused by the micro holes in the film has been minimized. The sensor suits for mass production.