Method of manufacturing a capacitive humidity sensor.

摘要

A capacitive humidity sensor is made by forming a bottom electrode (2) on an insulating substrate, (1) depositing a uniform thickness humidity-sensitive polymer layer (5) on the electrode while leaving contact areas uncovered, and activating polymer surface bonds by ion bombardment. A colloidal dispersion of SiO2 or Al2O3 particles (6) of uniform size is applied to the surface and dried. A cover electrode is deposited on the particles, and the particles are then removed together with the parts of the cover electrode overlying them using an ultrasound bath. The polymer is pref. polyimide with a polyimide acid used as a precursor. The particles are pref. about 250 nm in size. The cover electrode is pref. deposited over an adhesive metal layer applied over the particles.