Patent ID: 8047074

Claim:
A humidity sensor, comprising: a substrate; an open cavity with an open upper portion, the open cavity being formed to have a depth and a width in the substrate; a plurality of electrode pads formed on the substrate; a heater connected to one pad of the electrode pads at a first end and connected to another pad of the electrode pads at a second end and suspended over the open cavity; a plurality of sensing electrodes formed on the same plane as the heater, and suspended over the open cavity to output a sensed signal to the electrode pads; a humidity sensitive layer formed on the heater and the sensing electrodes suspended over the open cavity, and changed in characteristic according to the humidity; and an ambient temperature measurement part configured to measure the temperature around the humidity sensor, wherein the temperature is used as a reference temperature to control a heating temperature of the heater, wherein the heater is formed in a bridge shape and disposed in the middle of the upper portion of the open cavity, the heater including comb-shaped branches at both sides.