Pressure Transducer With Capacitively Coupled Source Electrode

摘要

A capacitive pressure transducer of an embodiment of the present invention capacitively couples two electrodes on a substrate with a diaphragm electrode to form a transducing circuit without the need for a physical connection between the electrodes. Embodiments of the present invention have a substrate with a coupling electrode and a sensing electrode and an attached diaphragm with a diaphragm electrode. A spacer positioned between the substrate and the diaphragm provides for a cavity that defines a gap between the sensing electrode and the diaphragm electrode. A dielectric spacer may be positioned over the coupling electrode to increase the capacitance between the coupling electrode and the diaphragm electrode. The capacitive pressure transducer has similar electrical characteristics as existing capacitive pressure transducers, is easier to manufacture, and has long-term reliability and durability improvements brought about by the elimination of mechanical interconnects and additional conductive materials.

主权项

1. A capacitive pressure transducer, comprising:
a substrate having thereon a coupling electrode and a sensing electrode; a diaphragm having a diaphragm electrode thereon; a spacer positioned between the substrate and the diaphragm, the spacer providing a cavity that includes a gap between the coupling electrode and the diaphragm electrode and between the sensing electrode and the diaphragm electrode, the coupling electrode and the diaphragm electrode defining a coupling capacitance and the sensing electrode and the diaphragm electrode defining a sensing capacitance, wherein pressure change on the diaphragm causes a corresponding change in the sensing capacitance.