Inventors:
Yousef M. Alimi - Allen TX, US
Richard A. Davis - Plano TX, US
Assignee:
Honeywell International Inc. - Morristown NJ
International Classification:
G01R 27/26
H01G 5/012
Abstract:
An improved relative humidity sensor apparatus that provides a more accurate measurement of humidity in the presence of water condensation. A series capacitive sensor includes a thin porous platinum top plate, a humidity sensitive polyimide dielectric, and two metal bottom plates on a semiconductor substrate. The two capacitors can be wired in series such that the metal bottom plates form independent, electrically driven connections. The thin top layer can form a top plate. Changes in humidity affect the humidity sensitive dielectric thereby causing changes in the capacitive value. A P-well layer and a P-plus layer can be added at the perimeter of the substrate to create a path for a parasitic capacitance caused by water condensation to connect to one or more connection nodes, thereby preventing erroneous measurements of humidity in the presence of water condensation.