Back to results
US 6,647,782 B2Granted
Capacitive humidity sensor
AssigneeDenso Corporation
InventorInao Toyoda
Life of this patent
Estimating the term…
Abstract
A humidity sensor has two detection electrodes located on a semiconductor substrate and a humidity sensitive film. The capacitance of the film changes in response to humidity. The sensor includes a reference capacitor and a feedback capacitor. An electrode of each capacitor is located beneath one of the detection electrodes to limit the size of the device.
Claims12
A capacitive humidity sensor comprising:
- a semiconductor substrate;
- circuit devices formed on a surface of the semiconductor substrate;
- two detection electrodes, which are isolated from one another and are opposed to one other, wherein the detection electrodes are formed on the surface of the semiconductor substrate;
- and
- a humidity-sensitive film, the capacitance of which changes in response to humidity, placed between the detection electrodes and formed on the surface of the semiconductor substrate, wherein:
- the capacitance between the detection electrodes changes in response to changes in the surrounding humidity;
- the circuit devices make up switched capacitor circuits comprising a reference capacitor and feedback capacitor that convert changes in capacitance between the detection electrodes into voltage signal output;
- and
- at least one of the reference capacitor and the feedback capacitor is an underlying capacitor and is located beneath one of the detection electrodes.
6 more elements
A capacitive humidity sensor comprising:
- a semiconductor substrate;
- circuit devices formed on a surface of the semiconductor substrate;
- a first insulating film formed on the surface of the semiconductor substrate;
- two detection electrodes formed in isolation from each other and opposed to each other on the first insulating film;
- a second insulating film formed to cover the detection electrodes;
- and
- a humidity-sensitive film, the capacitance of which changes in response to humidity, formed on the second insulating film to cover the detection electrodes and an area between the detection electrodes, wherein:
- the capacitance between the detection electrodes changes in response to changes in surrounding humidity;
- the circuit devices make up switched capacitor circuits comprising a reference capacitor and a feedback capacitor for converting changes in capacitance between the detection electrodes into voltage signal output;
- and
- at least one of the reference capacitor and the feedback capacitor is an underlying capacitor that is formed beneath one of the detection electrodes.
8 more elements
Dependencies are inferred from the claim text.