Multi-axis direction measurement flow sensor chip

Abstract

The utility model relates to a multi-axis direction measurement flow sensor chip. The light emitting diode comprises a substrate; the central heat source structure is arranged on the substrate and is of a cross structure; the first upstream thermopile temperature measuring element, the first downstream thermopile temperature measuring element, the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are respectively arranged on the substrate; the first upstream thermopile temperature measuring element and the first downstream thermopile temperature measuring element are symmetrically arranged by taking the cross of the central heat source structure as a 45-degree axis of an XY-axis coordinate system, and the length direction of the first upstream thermopile temperature measuring element and the length direction of the first downstream thermopile temperature measuring element are parallel to a 135-degree axis; the second upstream thermopile temperature measurement element and the second downstream thermopile temperature measurement element are symmetrically arranged by using a 135-degree axis of a cross XY-axis coordinate system of the central heat source structure, and the length directions of the second upstream thermopile temperature measurement element and the second downstream thermopile temperature measurement element are parallel to a 45-degree axis; the first upstream thermopile temperature measurement element and the second upstream thermopile temperature measurement element are symmetrically arranged along the X axis. The flow monitoring device is suitable for flow monitoring in a complex airflow environment.

Description

Technical Field

[0001] The utility model relates to the technical field of flow sensors, in particular to a multi-axis direction flow sensor chip. Background Art

[0002] Thermal flow sensors measure flow by providing a constant voltage to a heating resistor and based on the temperature difference between the upstream and downstream temperature measuring elements under different flow rate conditions. According to the type of temperature measuring resistor used, thermal flow sensors can be divided into two types: thermistor type and thermopile type. Thermistor sensors rely on the characteristics of thermistors to measure temperature, while thermopile sensors are composed of multiple thermocouples in series. Thermocouples are closed loops consisting of two conductors of different materials. When there is a temperature difference between the two ends, a potential difference will be generated in the loop. This phenomenon is called the Seebeck effect.

[0003] The main MEMS flow sensors currently available on the market are usually single-flow or single-axis bidirectional designs. When faced with multi-directional gas flows, errors will occur and they cannot accurately reflect the actual flow conditions. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the single flow direction or single-axis bidirectional design of the flow sensor in the prior art cannot accurately reflect the actual flow conditions of multi-directional gas flow.

[0005] In order to solve the above technical problems, the utility model provides a multi-axis direction flow measurement sensor chip, comprising:

[0006] substrate;

[0007] A central heat source structure is disposed on the substrate and is in a cross structure;

[0008] Four groups of thermopile temperature measuring elements, including a first upstream thermopile temperature measuring element, a first downstream thermopile temperature measuring element, a second upstream thermopile temperature measuring element, and a second downstream thermopile temperature measuring element, which are respectively arranged on the substrate;

[0009] Among them, the first upstream thermopile temperature measuring element and the first downstream thermopile temperature measuring element are respectively arranged symmetrically with the cross of the central heat source structure as the 45° axis of the XY axis coordinate system, and the length direction is parallel to the 135° axis; the second upstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element are respectively arranged symmetrically with the 135° axis of the cross XY axis coordinate system of the central heat source structure, and the length direction is parallel to the 45° axis; the first upstream thermopile temperature measuring element is respectively arranged symmetrically with the second upstream thermopile temperature measuring element along the X axis and symmetrically with the second downstream thermopile temperature measuring element along the Y axis.

[0010] In one embodiment of the present invention, the substrate includes a silicon wafer and a support structure layer disposed on a surface of the silicon wafer.

[0011] In one embodiment of the present invention, the support structure layer includes a silicon oxide support layer and a silicon nitride support layer which are sequentially arranged on the surface of the substrate.

[0012] In one embodiment of the present invention, the thickness of the silicon oxide support layer is 0.1-5 μm; the thickness of the silicon nitride support layer is 0.01-0.5 μm.

[0013] In one embodiment of the present invention, the first upstream thermopile temperature measuring element and the second upstream thermopile temperature measuring element both include multiple rows of upstream temperature measuring element thermopiles arranged in parallel; the first downstream thermopile temperature measuring element and the second downstream thermopile temperature measuring element both include multiple rows of downstream temperature measuring element thermopiles arranged in parallel.

[0014] In one embodiment of the present invention, the material of the central heat source structure includes platinum or nickel.

[0015] The above technical solution of the utility model has the following advantages compared with the prior art:

[0016] The utility model discloses a multi-axis flow sensor chip, which can accurately measure gas flow from multiple directions, including the X-axis and Y-axis, the 45° axis and the 135° axis. This enables the sensor to provide more comprehensive and accurate flow data in complex fluid environments. In addition, by adopting a cross-structured central heat source and a diagonally arranged thermopile temperature measuring element, the effective length of the thermocouple is increased and the sensitivity of temperature detection is improved. The chip has a wider range of application scenarios, and is particularly suitable for flow monitoring in complex airflow environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments of the utility model in combination with the accompanying drawings.

[0018] Figure 1 It is a schematic diagram of the overall top view structure of the multi-axis direction measurement flow sensor chip of the utility model.

[0019] Description of the Figures in the Specification:

[0020] 100, substrate;

[0021] 1. Central heat source structure;

[0022] 2. First upstream thermopile temperature measuring element;

[0023] 3. Second upstream thermopile temperature measuring element;

[0024] 4. First downstream thermopile temperature measuring element;

[0025] 5. Second downstream thermopile temperature measuring element;

[0026] 6. Upstream temperature measuring element thermopile;

[0027] 7. Downstream temperature measuring element thermopile. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0029] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0030] In the present utility model, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present utility model, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0031] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0032] Reference Figure 1 As shown, a multi-axis direction flow measurement sensor chip of the utility model comprises:

[0033] Substrate 100;

[0034] A central heat source structure 1 is disposed on the substrate 100 and is in a cross structure; the material of the central heat source structure 1 includes platinum or nickel;

[0035] Four groups of thermopile temperature measuring elements, including a first upstream thermopile temperature measuring element 2, a first downstream thermopile temperature measuring element 4, a second upstream thermopile temperature measuring element 3 and a second downstream thermopile temperature measuring element 5, which are respectively arranged on the substrate 100;

[0036] Among them, the first upstream thermopile temperature measuring element 2 and the first downstream thermopile temperature measuring element 4 are respectively arranged symmetrically with the cross of the central heat source structure 1 as the 45° axis of the XY axis coordinate system, and the length direction is parallel to the 135° axis; the second upstream thermopile temperature measuring element 3 and the second downstream thermopile temperature measuring element 5 are respectively arranged symmetrically with the 135° axis of the cross XY axis coordinate system of the central heat source structure 1, and the length direction is parallel to the 45° axis; the first upstream thermopile temperature measuring element 2 is respectively arranged symmetrically with the second upstream thermopile temperature measuring element along the X axis and symmetrically with the second downstream thermopile temperature measuring element 5 along the Y axis.

[0037] In one embodiment, the substrate 100 includes a silicon wafer and a support structure layer disposed on a surface of the silicon wafer.

[0038] Specifically, the support structure layer includes a silicon oxide support layer and a silicon nitride support layer sequentially arranged on the surface of the substrate 100. The thickness of the silicon oxide support layer is 0.1-5 μm; the thickness of the silicon nitride support layer is 0.01-0.5 μm. The double-layer support structure (silicon oxide and silicon nitride) improves the stress of the support film layer through stress reverse action, making the chip more stable, reducing deformation or damage caused by thermal stress, and increasing the durability and reliability of the sensor.

[0039] In one embodiment, the first upstream thermopile temperature measuring element 2 and the second upstream thermopile temperature measuring element 3 both include multiple rows of upstream temperature measuring element thermopiles 6 arranged in parallel; the first downstream thermopile temperature measuring element 4 and the second downstream thermopile temperature measuring element 5 both include multiple rows of downstream temperature measuring element thermopiles 7 arranged in parallel.

[0040] It can be understood that the multiple rows of upstream temperature measuring element thermopiles 6 are connected by wires, and the multiple rows of downstream temperature measuring element thermopiles 7 are connected by wires.

[0041] Through the above settings, the diagonal design can make the thermocouple longer in a limited area, thereby improving the sensitivity of chip temperature detection. At the same time, no matter the flow rate flows in from the six directions of X-axis, Y-axis, 45° axis, 135° axis or any direction, it can be stably detected.

[0042] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to examples, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A multi-axis flow sensor chip, characterized in that: include: Substrate (100); A central heat source structure (1) is arranged on the substrate (100) and is in a cross structure; Four groups of thermopile temperature measuring elements, comprising a first upstream thermopile temperature measuring element (2), a first downstream thermopile temperature measuring element (4), a second upstream thermopile temperature measuring element (3) and a second downstream thermopile temperature measuring element (5), which are respectively arranged on the substrate (100); The first upstream thermopile temperature measuring element (2) and the first downstream thermopile temperature measuring element (4) are respectively arranged symmetrically with the cross of the central heat source structure (1) as the 45° axis of the XY axis coordinate system, and the length direction is parallel to the 135° axis; the second upstream thermopile temperature measuring element (3) and the second downstream thermopile temperature measuring element (5) are respectively arranged symmetrically with the 135° axis of the cross XY axis coordinate system of the central heat source structure (1), and the length direction is parallel to the 45° axis; the first upstream thermopile temperature measuring element (2) is respectively arranged symmetrically with the second upstream thermopile temperature measuring element along the X axis and symmetrically with the second downstream thermopile temperature measuring element (5) along the Y axis.

2. A multi-axis direction flow measurement sensor chip according to claim 1, characterized in that: The substrate (100) comprises a silicon wafer and a support structure layer arranged on the surface of the silicon wafer.

3. A multi-axis direction flow measurement sensor chip according to claim 2, characterized in that: The support structure layer comprises a silicon oxide support layer and a silicon nitride support layer which are sequentially arranged on the surface of the substrate (100).

4. A multi-axis direction flow measurement sensor chip according to claim 3, characterized in that: The thickness of the silicon oxide support layer is 0.1-5 μm; the thickness of the silicon nitride support layer is 0.01-0.5 μm.

5. The multi-axis direction flow sensor chip according to claim 1, characterized in that: The first upstream thermopile temperature measuring element (2) and the second upstream thermopile temperature measuring element (3) both comprise a plurality of rows of upstream temperature measuring element thermopiles (6) arranged in parallel; and the first downstream thermopile temperature measuring element (4) and the second downstream thermopile temperature measuring element (5) both comprise a plurality of rows of downstream temperature measuring element thermopiles (7) arranged in parallel.

6. The multi-axis direction flow measurement sensor chip according to claim 1, characterized in that: The material of the central heat source structure (1) includes platinum or nickel.

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