Method for reducing the temperature dependence of a capacitive sensor and a capacitive sensor construction
View Patent ↗A method of manufacturing a sensor including forming an insulating layer on top of a conductive substrate, and forming a conducting electrode on top of the insulating layer. Further, the insulating layer is formed to include support areas formed at edges of the conducting electrode and a partial area formed under the conducting electrode, and a thickness (d 2 ) of the partial area of the insulating layer is less than a thickness (d 1 ) of the support areas of the insulating area.
1. A method of manufacturing a capacitive sensor, comprising:
forming an insulating layer on top of a conductive substrate; and
forming a first conducting electrode on top of the insulating layer,
wherein the insulating layer is formed to include support areas formed at edges of the first conducting electrode and a partial area formed under the first conducting electrode,
wherein said support areas of the insulating layer are formed to support a second conducting electrode located a predetermined distance from the first conducting electrode and a forming capacitance element,
wherein a thickness (d 2 ) of the partial area of the insulating layer is less than a thickness (d 1 ) of the support areas of the insulating layer, and
wherein a top surface of the conductive substrate includes feed-through protrusion formed at areas corresponding to the thickness (d 1 ) of the support areas of the insulating layer such that a top surface of the insulating layer is planar.
2. The method of claim 1 , wherein a ratio of the thicknesses (d 2 )/(d 1 ) of the insulating layer is between 0.05 and 0.8.
3. The method of claim 2 , wherein the ratio of the thicknesses (d 2 )/(d 1 ) of the insulating layer is substantially 0.5.
4. The method of claim 1 , wherein the conductive substrate comprises an electrically conductive silicon substrate.
5. The method of claim 1 , wherein the insulating layer comprises an insulating glass layer.
6. A capacitive sensor construction, comprising:
an insulating layer on top of a conductive substrate;
a first conducting electrode on top of the insulating layer; and
a second conducting electrode located a predetermined distance from the first conducting electrode and forming a capacitance element,
wherein the insulating layer includes support areas at edges of the first conducting electrode and a partial area under the first conducting electrode, said support areas of the insulating layer supporting said second conducting electrode.
wherein a thickness (d 2 ) of the partial area of the insulating layer is less than a thickness (d 1 ) of the support areas of the insulating layer, and
wherein a top surface of the conductive substrate includes feed-through protrusions formed at areas corresponding to the thickness (d 1 ) of the support areas of the insulating layer such that a top surface of the insulating layer is planar.
7. The capacitive sensor construction of claim 6 , wherein a ratio of the thicknesses (d 2 )/(d 1 ) of the insulating layer is between 0.05 and 0.8.
8. The capacitive sensor of construction claim 7 , wherein the ratio of the thicknesses (d 2 )/(d 1 ) of the insulating layer is substantially 0.5.
9. The capacitive sensor of construction claim 6 , wherein the conductive substrate comprises an electrically conductive silicon substrate.
10. The capacitive sensor of construction claim 6 , wherein the insulating layer comprises an insulating glass layer.
11. The capacitive sensor of construction claim 6 , further comprising:
a feed-through protrusion through the insulating layer to create an electrical contact between the first conducting electrode and the conductive substrate when the sensor is activated.