Sensor bridge with thermally isolating apertures
First Claim
1. A flow sensor for sensing a flow of a fluid stream, the flow sensor comprising:
- a substrate having a top surface;
a depression extending into the substrate from the top surface, the depression having an upstream side, a downstream side, a first lateral side and a second lateral side, wherein during use of the flow sensor, the fluid stream flows from the upstream side towards the downstream side;
a bridge extending across the depression from the first lateral side of the depression to the second lateral side, the bridge being supported by the substrate adjacent the first lateral side and the second lateral side of the depression, wherein the bridge includes first and second lateral sides extending substantially parallel to a direction of fluid flow, and a leading edge and a spaced trailing edge each extending from the first lateral side to the second lateral side of the depression, the leading edge of the bridge being spaced apart from the upstream side of the depression defining a fluid inlet and the trailing edge of the bridge being spaced apart from the downstream side of the depression defining a fluid outlet;
a heater element provided on the bridge;
a first sensor element provided on the bridge adjacent an upstream side of the heater element;
a second sensor element provided on the bridge adjacent a downstream side of the heater element; and
a plurality of apertures extending through the bridge, the plurality of apertures disposed at spaced locations adjacent the first lateral side of the depression along a direction that is substantially parallel to the direction of fluid flow.
1 Assignment
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Accused Products
Abstract
A sensor having a sensor bridge supported above a substrate is disclosed. A number of thermally isolating apertures are provided in the sensor bridge to help increase the thermal isolation of the sensor bridge from the substrate. In one illustrative embodiment, a heater element, an upstream sensor element, and/or a downstream sensor element are provided on the sensor bridge. A plurality of apertures may extend through the sensor bridge to thermally isolate the heater element, the upstream and/or downstream sensor element from the substrate and/or from each other. In one illustrative embodiment, the plurality of apertures may be provided at spaced locations adjacent a first lateral side of the sensor bridge, adjacent the second lateral side of the sensor bridge, between the heater element and the upstream sensor element, and/or between the heater element and the downstream sensor element. In some cases, the plurality of apertures may be substantially round, oval, rectangular and/or any other suitable shape.
41 Citations
21 Claims
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1. A flow sensor for sensing a flow of a fluid stream, the flow sensor comprising:
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a substrate having a top surface; a depression extending into the substrate from the top surface, the depression having an upstream side, a downstream side, a first lateral side and a second lateral side, wherein during use of the flow sensor, the fluid stream flows from the upstream side towards the downstream side; a bridge extending across the depression from the first lateral side of the depression to the second lateral side, the bridge being supported by the substrate adjacent the first lateral side and the second lateral side of the depression, wherein the bridge includes first and second lateral sides extending substantially parallel to a direction of fluid flow, and a leading edge and a spaced trailing edge each extending from the first lateral side to the second lateral side of the depression, the leading edge of the bridge being spaced apart from the upstream side of the depression defining a fluid inlet and the trailing edge of the bridge being spaced apart from the downstream side of the depression defining a fluid outlet; a heater element provided on the bridge; a first sensor element provided on the bridge adjacent an upstream side of the heater element; a second sensor element provided on the bridge adjacent a downstream side of the heater element; and a plurality of apertures extending through the bridge, the plurality of apertures disposed at spaced locations adjacent the first lateral side of the depression along a direction that is substantially parallel to the direction of fluid flow. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A flow sensor for sensing a flow of a fluid stream, the flow sensor comprising:
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a substrate; a bridge having an upstream side, a downstream side, a first lateral side and a second lateral side, wherein during use of the flow sensor, the fluid stream flows in a direction from the upstream side towards the downstream side of the bridge, and wherein the first and second lateral sides of the bridge extend substantially parallel to a direction of fluid flow; the bridge is spaced from the substrate between the upstream side and the downstream side of the bridge, and is also spaced from the substrate between the first lateral side and the second lateral side of the bridge, the bridge being supported by the substrate adjacent the first lateral side and the second lateral side of the bridge; a heater element supported by the bridge; a first sensor element supported by the bridge adjacent the heater element; and a plurality of spaced apertures extending through the bridge, the plurality of spaced apertures spaced from one another in a direction that is substantially parallel to the direction of fluid flow of the fluid stream. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A flow sensor for sensing a flow of a fluid stream, the flow sensor comprising:
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a substrate having a top surface; a depression extending into the substrate from the top surface, the depression having an upstream side, a downstream side, a first lateral side and a second lateral side, wherein during use of the flow sensor, the fluid stream flows from the upstream side towards the downstream side, and wherein the first and second lateral sides of the depression extend parallel to a direction of fluid flow; a bridge extending across the depression from the first lateral side of the depression to the second lateral side, the bridge being supported by the substrate adjacent the first lateral side and the second lateral side of the depression and having a leading edge and a trailing edge extending from the first lateral side to the second lateral side of the depression, the leading edge of the bridge being spaced apart from the upstream side of the depression defining a fluid inlet and the trailing edge of the bridge being spaced apart from the downstream side of the depression defining a fluid outlet; a heater element supported by the bridge; a sensor element supported by the bridge adjacent the heater element; and an array of apertures extending through the bridge, the array of apertures having an array length that extends in a direction generally from the first lateral side toward the second lateral side of the depression, the array of apertures is further situated between the heater element and the sensor element. - View Dependent Claims (20, 21)
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Specification