Concentric coplanar capacitive sensor system with quantitative model

摘要

A concentric coplanar capacitive sensor includes a charged central disc forming a first electrode, an outer annular ring coplanar with and outer to the charged central disc, the outer annular ring forming a second electrode, and a gap between the charged central disc and the outer annular ring. The first electrode and the second electrode may be attached to an insulative film. A method provides for determining transcapacitance between the first electrode and the second electrode and using the transcapacitance in a model that accounts for a dielectric test piece to determine inversely the properties of the dielectric test piece.

主权项

1. A concentric coplanar capacitive sensor system, comprising:
a concentric coplanar capacitive sensor comprising (a) a charged central disc forming a first electrode, (b) an outer annular ring coplanar with and outer to the charged central disc, the outer annular ring forming a second electrode, (c) a gap between the charged central disc and the outer annular ring, and (d) the first electrode and the second electrode attached to an insulative film; a capacitance measuring circuit electrically connected to the concentric coplanar capacitive sensor for measuring transcapacitance between the first electrode and the second electrode for use in evaluating a dielectric test piece; a processor operatively connected to the first electrode, the processor configured to use the transcapacitance as an input to a quantitative model of the dielectric test piece to determine inversely properties of the dielectric test piece; wherein the quantitative model provides a quantitative relationship between a transcapacitance measured with the concentric coplanar capacitive sensor and permittivity and thickness of each of a plurality of layers in the dielectric test piece.