Humidity sensor

摘要

A humidity sensor may include a first substrate having a recess formed in a first side, a second substrate and an insulating layer supported by the second substrate. The second substrate and the insulating layer may be supported by the first side of the first substrate and extend over the recess to form a diaphragm with the insulating layer facing the recess. The diaphragm may be at least partially thermally isolated from a remainder of the second substrate. A resistive heater element may be supported by the diaphragm. A pair of sensing electrodes are electrically separated from each other and supported by the diaphragm. A sensing material is disposed over the pair of sensing electrodes, wherein an electrical property of the sensing material changes in response to a change in moisture content of the sensing material.

主权项

1. A humidity sensor comprising:
a first substrate having a recess formed in a first side; a second substrate; an insulating layer supported by the second substrate; the second substrate and the insulating layer supported by the first side of the first substrate and extending over the recess to form a diaphragm, with the insulating layer facing the recess; a trench in the second substrate extending around or substantially around the diaphragm, the trench at least partially filled with an oxide to thermally insulate the diaphragm from a remainder of the second substrate; a resistive heater element supported by the diaphragm; a pair of sensing electrodes electrically separated from each other and supported by the diaphragm; and a sensing material disposed over the pair of sensing electrodes, wherein an electrical property of the sensing material is configured to change in response to a change in moisture content of the sensing material.