New type of flow sensor chip

Abstract

This invention discloses a novel flow sensor chip, comprising: a heating component, an upstream component, a downstream component, an insulating diaphragm, and a sensor substrate; the heating component is connected to the insulating diaphragm; the upstream component includes a hot end near the heating component and a cold end away from the heating component; the downstream component includes a hot end near the heating component and a cold end away from the heating component; the detected airflow flows sequentially through the upper surface of the upstream component, the upper surface of the heating component, and the upper surface of the downstream component; the insulating diaphragm has a through hole for connecting the upper and lower parts of the insulating diaphragm to balance the air pressure above and below the insulating diaphragm. The novel flow sensor chip of this invention, with the through hole in the insulating diaphragm, allows for the passage of air pressure above and below the insulating diaphragm, preventing the insulating diaphragm from being under pressure for extended periods, and thus balancing the air pressure between the air in the lower cavity and the air above the insulating diaphragm, thereby increasing the lifespan of the sensor chip.

Description

Technical Field

[0001] This invention belongs to the field of flow sensor technology, and specifically relates to a novel flow sensor chip. Background Technology

[0002] Currently, flow sensors are widely used in the detection of flow in oil and gas, automotive engines, and medical equipment. In some existing flow sensor structures, the sensor sometimes needs to be placed on a suspended diaphragm. However, the diaphragm is easily affected by parameters such as the pressure and temperature of the fluid being measured, causing an imbalance in air pressure above and below the sensor chip diaphragm, which can lead to diaphragm rupture or significantly reduce the lifespan of the chip. Summary of the Invention

[0003] This invention provides a novel flow sensor chip to solve the aforementioned technical problems, specifically employing the following technical solution:

[0004] A novel flow sensor chip, comprising:

[0005] Heating components, used to generate heat;

[0006] The upstream component is located upstream of the heating component and is spaced apart from the heating component;

[0007] The downstream component is located downstream of the heating component and is spaced apart from the heating component;

[0008] An insulating film is located below the heating element to insulate against heat.

[0009] It supports at least a portion of the heating element, the upstream element, and at least a portion of the downstream element;

[0010] The sensor substrate is connected to the isolation film and located on both sides of the isolation film.

[0011] The heating element is connected to the insulating diaphragm.

[0012] The upstream component includes a hot end close to the heating component and a cold end away from the heating component. The hot end of the upstream component is connected to and located above the insulating film, and the cold end of the upstream component is connected to and located above the sensor substrate.

[0013] The downstream component includes a hot end close to the heating component and a cold end away from the heating component. The hot end of the downstream component is connected to the sensor substrate and is located above the sensor substrate, and the cold end of the downstream component is connected to the sensor substrate and is located above the sensor substrate.

[0014] The detected airflow flows sequentially over the upper surface of the upstream component, the upper surface of the heating component, and the upper surface of the downstream component;

[0015] The isolation membrane is provided with a through hole for connecting the top and bottom of the isolation membrane to balance the air pressure above and below the isolation membrane.

[0016] Furthermore, the through-hole is located at the edge of the insulating film component.

[0017] Furthermore, the length of the through-hole is 0.05% to 5% of the total length of the insulating film.

[0018] Furthermore, the distance between the upstream component and the isolation film is equal to the distance between the downstream component and the isolation film.

[0019] Furthermore, the length of the portion of the upstream component that contacts the insulating film is greater than the length of the portion that contacts the sensor substrate;

[0020] The length of the downstream component in contact with the isolation film is greater than the length of the component in contact with the sensor substrate.

[0021] The length of the portion of the upstream component that contacts the isolation film is equal to the length of the portion of the downstream component that contacts the isolation film.

[0022] The length of the portion of the upstream component that contacts the sensor substrate is equal to the length of the portion of the downstream component that contacts the sensor substrate.

[0023] Furthermore, the heating element is made of a conductive material;

[0024] The upstream component is made of one of the following: a doped semiconductor, a metal, or a metal compound.

[0025] The downstream component is made of a metal or a metal compound.

[0026] Furthermore, the insulating thin film is fabricated by processing the insulating material in the semiconductor material on insulator using micro-machining technology;

[0027] The through holes on the insulating film are made by one of the following techniques: micro-machining, machining, or laser processing.

[0028] Furthermore, micro-nano fabrication technology includes semiconductor dry chemical etching technology, chemical wet etching technology, physical etching technology, and hybrid etching technology.

[0029] Furthermore, the new flow sensor chip also includes:

[0030] The first detection unit is used to detect the first voltage difference between the hot end and the cold end of the upstream component, and it is connected to the upstream component.

[0031] The second detection unit is used to detect the second voltage difference between the hot end and the cold end of the downstream component, and it is connected to the downstream component.

[0032] Furthermore, the new flow sensor chip also includes:

[0033] A calculation unit, used to calculate the flow rate of the airflow passing through the novel flow sensor chip based on a first voltage difference and a second voltage difference, is connected to a first detection unit and a second detection unit.

[0034] The advantage of this invention is that the novel flow sensor chip provided has through holes in the isolation diaphragm, which can allow air pressure to pass through the upper and lower parts of the isolation diaphragm, preventing the isolation diaphragm from being under pressure for a long time. This helps to balance the air pressure between the air in the lower cavity and the upper part of the isolation diaphragm, thereby increasing the service life of the sensor chip.

[0035] The advantages of this invention also lie in the novel flow sensor chip provided. During the packaging process of the flow sensor chip, when the heating component is heated, heat accumulates below the insulating film, causing the temperature to rise. The through-hole allows for the passage of air pressure from above and below, preventing the film from being under pressure for extended periods and further increasing the lifespan of the sensor chip. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a novel flow sensor chip according to the present invention;

[0037] The novel flow sensor chip 100, heating component 10, upstream component 20, downstream component 30, insulating film component 40, and sensor substrate 50 are included. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1The illustration shows a novel flow sensor chip 100 according to this application, comprising: a heating element 10, an upstream element 20, a downstream element 30, an insulating film 40, and a sensor substrate 50. The heating element 10 generates heat when energized. The upstream element 20 is located upstream of the heating element 10 and spaced apart from it. The downstream element 30 is located downstream of the heating element 10 and spaced apart from it. The insulating film 40 is located below the heating element 10 to insulate against heat and supports at least a portion of the heating element 10, the upstream element 20, and the downstream element 30. The sensor substrate 50 is connected to the insulating film 40 and located on both sides of the insulating film 40. The heating element 10 is connected to the insulating film 40. The upstream component 20 includes a hot end near the heating component 10 and a cold end away from the heating component 10. The hot end of the upstream component 20 is connected to and above the insulating film 40, and the cold end of the upstream component 20 is connected to and above the sensor substrate 50. The downstream component 30 includes a hot end near the heating component 10 and a cold end away from the heating component 10. The hot end of the downstream component 30 is connected to and above the sensor substrate 50, and the cold end of the downstream component 30 is connected to and above the sensor substrate 50. The detected airflow flows sequentially over the upper surface of the upstream component 20, the upper surface of the heating component 10, and the upper surface of the downstream component 30.

[0040] Figure 1 As not shown, the novel flow sensor chip 100 also includes: a first detection unit, a second detection unit, and a calculation unit.

[0041] Specifically, a first detection unit, connected to the upstream component 20, detects a first voltage difference between the hot and cold ends of the upstream component 20. A second detection unit, connected to the downstream component 30, detects a second voltage difference between the hot and cold ends of the downstream component 30. A calculation unit is connected to both the first and second detection units. The calculation unit calculates the flow rate of the airflow passing through the novel flow sensor chip 100 based on the first and second voltage differences.

[0042] In the embodiments of this application, the isolation diaphragm 40 is provided with a through hole for connecting the upper and lower parts of the isolation diaphragm 40 to balance the air pressure above and below the isolation diaphragm 40. This serves as a stress relief point, preventing the isolation diaphragm 40 from being in a high-stress state for extended periods and increasing the service life of the novel flow sensor chip 100. When gas flows over the novel flow sensor chip 100, the flow velocity is high, resulting in low pressure. If the isolation diaphragm 40 were not provided with a through hole, it would bulge upwards, potentially causing the diaphragm to rupture or reducing the service life of the sensor chip.

[0043] The through-hole provided in this application allows for the passage of air pressure above and below the isolation diaphragm 40, preventing the diaphragm 40 from being under pressure for extended periods. This balances the air pressure between the lower cavity and the upper cavity of the isolation diaphragm 40, thereby increasing the lifespan of the sensor chip. Simultaneously, the through-hole allows for the passage of air pressure above and below the isolation diaphragm 40. The force generated by the flowing air causes the air pressure to circulate, driving the heat generated by the heating element 10 to circulate internally, resulting in a more uniform heat distribution and more accurate airflow test results.

[0044] Furthermore, during the encapsulation of the flow sensor chip, heating the heating component 10 causes heat to accumulate below the insulating diaphragm 40, resulting in a temperature increase. The through-hole allows air pressure to pass through, preventing the diaphragm from being under pressure for extended periods and further extending the lifespan of the sensor chip.

[0045] In a preferred embodiment, the through-hole is located at the edge of the insulating film member 40. Specifically, the length of the through-hole is 0.05% to 5% of the total length of the insulating film member 40. Its shape includes, but is not limited to, circular, elliptical, square, rectangular, etc.

[0046] In a preferred embodiment, the distances from the upstream component 20 to the isolation film 40 and the distances from the downstream component 30 to the isolation film 40 are equal. Furthermore, the length of the portion of the upstream component 20 in contact with the isolation film 40 is greater than the length of the portion in contact with the sensor substrate 50. Similarly, the length of the portion of the downstream component 30 in contact with the isolation film 40 is greater than the length of the portion in contact with the sensor substrate 50. The lengths of the portions of the upstream component 20 and the downstream component 30 in contact with the isolation film 40 are equal.

[0047] Therefore, in this application, when no airflow passes through, the first voltage difference detected by the first detection unit and the second voltage difference detected by the second detection unit are equal. When airflow passes through, the airflow changes the temperature distribution above the heating component 10, the upstream component 20, and the downstream component 30. The first voltage difference detected by the first detection unit decreases, and the second voltage difference detected by the second detection unit increases. The calculation unit can calculate the flow velocity of the passing airflow based on the difference between the first voltage difference and the second voltage difference.

[0048] In a preferred embodiment, the heating element 10 is made of a conductive material. This includes, but is not limited to, doped semiconductors such as single-crystal silicon, polycrystalline silicon (α-type or β-type), metals or metal compounds, including but not limited to aluminum, iron, copper, platinum, and their compounds.

[0049] The upstream component 20 and the downstream component 30 are a third temperature control component. Specifically, the material of the upstream component 20 includes, but is not limited to, doped semiconductors such as monocrystalline silicon, polycrystalline silicon (α-type or β-type), metals, or metal compounds. The material of the downstream component 30 is a metal or metal compound, such as aluminum, iron, copper, platinum, and their compounds.

[0050] In a preferred embodiment, the insulating thin film 40 is fabricated by processing the insulating material in the semiconductor-on-insulator material using micro-machining technology. The semiconductor-on-insulator material comprises a substrate, an insulator, and a semiconductor. Specifically, the substrate includes, but is not limited to, silicon, silicon nitride, and other semiconductors and their compounds, with a thickness ranging from 10 μm to 1000 μm. The insulator includes, but is not limited to, silicon oxide, silicon nitride, and other compounds, with a thickness ranging from 10 nm to 10 μm. The semiconductor material includes, but is not limited to, doped semiconductors, such as single-crystal silicon, polycrystalline silicon (α-type or β-type), metals or metal compounds, including but not limited to aluminum, iron, copper, platinum, and their compounds, with a thickness ranging from 10 nm to 100 μm.

[0051] The vias on the isolation film 40 are fabricated using one of the following techniques: micro-machining, machining, or laser processing. It is understood that micro / nano fabrication techniques include semiconductor dry chemical etching, wet chemical etching, physical etching, and hybrid etching.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A flow sensor chip, characterized in that, Include: Heating components, used to generate heat; An upstream component is located upstream of the heating component and is spaced apart from the heating component; The downstream component is located downstream of the heating component and is spaced apart from the heating component; An insulating film is located below the heating element to insulate against heat. And supports the heating element, at least a portion of the upstream element, and at least a portion of the downstream element; The sensor substrate is connected to the insulating film and located on both sides of the insulating film. The heating component is connected to the insulating film; The upstream component includes a hot end near the heating component and a cold end away from the heating component. The hot end of the upstream component is connected to and located above the insulating film, and the cold end of the upstream component is connected to and located above the sensor substrate. The downstream component includes a hot end near the heating component and a cold end away from the heating component. The cold end of the downstream component is connected to the sensor base and is located above the sensor base. The hot end of the downstream component is connected to the sensor base and is located above the sensor base. The detected airflow flows sequentially over the upper surface of the upstream component, the upper surface of the heating component, and the upper surface of the downstream component; The insulating film is provided with a through hole for connecting the top and bottom of the insulating film to balance the air pressure above and below the insulating film; The through-hole is located at the edge of the insulating film; The length of the through hole is 0.05% to 5% of the total length of the insulating film. The distance between the upstream component and the heating component is equal to the distance between the downstream component and the heating component; The length of the portion of the upstream component that contacts the isolation film is greater than the length of the portion that contacts the sensor substrate; The length of the portion of the downstream component that contacts the isolation film is greater than the length of the portion that contacts the sensor substrate. The length of the portion of the upstream component that contacts the insulating film is equal to the length of the portion of the downstream component that contacts the insulating film. The length of the portion of the upstream component that contacts the sensor substrate is equal to the length of the portion of the downstream component that contacts the sensor substrate.

2. The flow sensor chip according to claim 1, characterized in that, The heating element is made of a conductive material; The upstream component is made of one of the following: doped semiconductor, metal, or metal compound. The downstream component is made of a metal or a metal compound.

3. The flow sensor chip according to claim 1, characterized in that, The isolation film is fabricated by processing the insulating material in the semiconductor material on insulator using micro-nano fabrication technology. The through-holes on the insulating film are fabricated using one of the following techniques: micro / nano fabrication, machining, or laser processing.

4. The flow sensor chip according to claim 3, characterized in that, The micro-nano fabrication technology includes semiconductor dry chemical etching technology, chemical wet etching technology, physical etching technology, and hybrid etching technology.

5. The flow sensor chip according to claim 1, characterized in that, The flow sensor chip also includes: A first detection unit is used to detect a first voltage difference between the hot end and the cold end of the upstream component, and is connected to the upstream component. The second detection unit is used to detect the second voltage difference between the hot end and the cold end of the downstream component, and it is connected to the downstream component.

6. The flow sensor chip according to claim 5, characterized in that, The flow sensor chip also includes: A calculation unit is used to calculate the flow rate of the airflow passing through the flow sensor chip based on the first voltage difference and the second voltage difference, and it is connected to the first detection unit and the second detection unit.

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