Capacitive pressure difference sensor and method for its manufacture
First Claim
1. A pressure difference sensor, comprising:
- first and second counterelectrodes;
a conductive disk arranged between said first and second counterelectrodes;
a first insulating layer, via which an outer edge of said conductive disk is connected with an outer edge of said first counterelectrode to form a first pressure chamber;
a second insulating layer, via which an outer edge of said conductive disk is connected with an outer edge of said second counterelectrode to form a second pressure chamber;
an opening provided in said first counterelectrode, via which opening said first pressure chamber is contactable with a first pressure; and
an opening provided in said second counterelectrode, via which opening said second pressure chamber is contactable with a second pressure, wherein;
said conductive disk is divided by a moat into an inner region serving as an electrode and an outer region electrically insulated therefrom by said moat;
said inner region includes a measuring membrane arranged between said two pressure chambers and an edge region surrounding said measuring membrane and clamped between the inner edges of said two insulating layers; and
said inner region forms with each of said counterelectrodes, in each case, a capacitor having a capacitance dependent on a pressure difference between said first and said second pressures acting on said measuring membrane;
wherein the capacitors are composed, in each case, of an inner capacitor portion, whose capacitor surfaces correspond to the area of the measuring membrane, and an outer capacitor portion externally surrounding the inner capacitor portion and wherein the area of the moat and the area of the total outer region of the disk do not, due to the moat, contribute to the capacitor surface of the outer capacitor portions.
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Accused Products
Abstract
A pressure difference sensor includes first and second counterelectrodes, a conductive disk between the counterelectrodes, a first insulating layer connecting an outer edge of the disk with an outer edge of the first counterelectrode forming a first pressure chamber, a second insulating layer connecting an outer edge of the disk with an outer edge of the second counterelectrode forming a second pressure chamber, an opening in the first counterelectrode, via which the first pressure chamber is contactable with a first pressure, and an opening in the second counterelectrode, via which the second pressure chamber is contactable with a second pressure. The disk is divided into inner and outer regions, the inner region includes a measuring membrane arranged between the two pressure chambers and an edge region, the inner region forms with each of the counterelectrodes a capacitor having a capacitance dependent on a pressure difference acting on the measuring membrane.
13 Citations
13 Claims
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1. A pressure difference sensor, comprising:
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first and second counterelectrodes; a conductive disk arranged between said first and second counterelectrodes; a first insulating layer, via which an outer edge of said conductive disk is connected with an outer edge of said first counterelectrode to form a first pressure chamber; a second insulating layer, via which an outer edge of said conductive disk is connected with an outer edge of said second counterelectrode to form a second pressure chamber; an opening provided in said first counterelectrode, via which opening said first pressure chamber is contactable with a first pressure; and an opening provided in said second counterelectrode, via which opening said second pressure chamber is contactable with a second pressure, wherein; said conductive disk is divided by a moat into an inner region serving as an electrode and an outer region electrically insulated therefrom by said moat; said inner region includes a measuring membrane arranged between said two pressure chambers and an edge region surrounding said measuring membrane and clamped between the inner edges of said two insulating layers; and said inner region forms with each of said counterelectrodes, in each case, a capacitor having a capacitance dependent on a pressure difference between said first and said second pressures acting on said measuring membrane; wherein the capacitors are composed, in each case, of an inner capacitor portion, whose capacitor surfaces correspond to the area of the measuring membrane, and an outer capacitor portion externally surrounding the inner capacitor portion and wherein the area of the moat and the area of the total outer region of the disk do not, due to the moat, contribute to the capacitor surface of the outer capacitor portions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for operating a pressure difference sensor comprising first and second counterelectrodes;
- a conductive disk arranged between said first and second counterelectrodes;
a first insulating layer, via which an outer edge of said conductive disk is connected with an outer edge of said first counterelectrode to form a first pressure chamber;
a second insulating layer, via which an outer edge of said conductive disk is connected with an outer edge of said second counterelectrode to form a second pressure chamber;
an opening provided in said first counterelectrode, via which opening said first pressure chamber is contactable with a first pressure; and
an opening provided in said second counterelectrode, via which opening said second pressure chamber is contactable with a second pressure, wherein;
said conductive disk is divided by a moat into an inner region serving as an electrode and an outer region electrically insulated therefrom by said moat;
said inner region includes a measuring membrane arranged between said two pressure chambers and an edge region surrounding said measuring membrane and clamped between the inner edges of said two insulating layers; and
said inner region forms with each of said counterelectrodes, in each case, a capacitor having a capacitance dependent on a pressure difference between said first and said second pressures acting on said measuring membrane, the method comprising the steps of;determining the pressure difference acting on the measuring membrane, based on a capacitance of a first capacitor formed by the disk inner region serving as electrode and the first counterelectrode and/or a capacitance of a second capacitor formed by the disk inner region serving as electrode and the second counterelectrode and/or determining a measure for a system pressure acting equally on the two sides of the pressure difference sensor based on a capacitance of a capacitor formed by the first and second counterelectrodes; wherein the capacitors are composed, in each case, of an inner capacitor portion, whose capacitor surfaces correspond to the area of the measuring membrane, and an outer capacitor portion externally surrounding the inner capacitor portion and wherein the area of the moat and the area of the total outer region of the disk do not, due to the moat, contribute to the capacitor surface of the outer capacitor portions. - View Dependent Claims (11, 12, 13)
- a conductive disk arranged between said first and second counterelectrodes;
Specification