A low-pressure drop flow channel assembly for thermal flow sensor chips

Abstract

This invention provides a low-pressure-drop flow channel assembly for a thermal flow sensor chip, comprising a flow channel assembly, a sensor chip assembly, and an external measurement circuit. The flow channel assembly includes a lower base, an intermediate sandwich plate, and a top cover plate. The top cover plate has an inlet connector and an outlet connector. The intermediate sandwich plate contains an inlet flow conditioning section and an outlet flow conditioning section. The top of the lower base has a downstream section communicating with the inlet flow conditioning section and a measurement section communicating with the outlet flow conditioning section. The sensor chip assembly includes a thermal flow sensor chip and a flexible interconnect. The thermal flow sensor chip is mounted on a chip mounting position on the measurement section. A wiring structure is sandwiched between the intermediate sandwich plate and the lower base, and the flexible interconnect is led out through the wiring structure to be electrically connected to the external measurement circuit. The beneficial effect of this invention is that it can achieve a repeatable flow development state in the measurement section while ensuring a low pressure drop, and at the same time taking into account the sealing performance of the chip mounting and the consistency of the flow field.

Description

Technical Field

[0001] This invention relates to the technical field of thermal gas flow measurement, and more specifically, to a low-pressure drop flow channel assembly for a thermal flow sensor chip. Background Technology

[0002] Thermal gas flow sensors utilize the heat transfer difference between a heating element and a temperature-sensitive element under forced gas convection to measure flow rate. They offer advantages such as compact structure, wide measurement range, and ease of miniaturization and integration, and are widely used in semiconductor precision manufacturing process control, environmental monitoring, medical respiratory systems, and automotive electronics. With the development of microelectromechanical processing (MEMS) and flexible interconnect packaging technologies, modular flow measurement schemes based on thermal flow sensor chips are gradually becoming mainstream. The measurement accuracy, repeatability, and dynamic response of these schemes largely depend on the flow field stability and the consistency of heat transfer boundary conditions within the measurement section where the sensor chip is located.

[0003] In existing technologies, thermal flow sensor chips are typically installed within straight-through or simple cavity-type flow channels. These flow channel structures often fail to adequately consider the inlet flow state in their design. Influenced by factors such as inlet connector type, abrupt changes in cavity geometry (e.g., sudden expansion / contraction, acute angle bends), and assembly errors, the inlet flow is prone to flow deviation, secondary flow, or local separation. This results in significant variations in the velocity profile and turbulence intensity within the measurement section depending on the operating conditions, leading to drift in the chip's convective heat transfer conditions. This manifests as zero-point drift, sensitivity dispersion, and poor repeatability of the calibration curve. Especially under low flow or pulsating flow conditions, these flow instabilities are more easily amplified, limiting the stability and comparability of thermal flow measurements.

[0004] Furthermore, to obtain sufficient heat transfer signals, existing solutions often improve local heat transfer intensity by reducing the flow channel cross-section, adding flow obstruction structures, or installing rectifiers. However, such measures often result in significant additional pressure drops, which not only increase system energy consumption but may also alter the upstream gas supply status and even cause instability in the flow source output, thereby further affecting measurement accuracy. In miniaturized packaging, improper flush mounting of chips, lead wire or flexible interconnect sealing, and stress relief treatment may also create local steps or gaps, inducing additional turbulence and local losses, further increasing the uncertainty of pressure drop and flow field.

[0005] Therefore, how to ensure a repeatable flow development state in the measurement section while maintaining a low pressure drop, and at the same time take into account the sealing of the chip installation and the consistency of the flow field, has become a technical problem that urgently needs to be solved in the field of thermal flow sensor chip packaging and flow channel design. Summary of the Invention

[0006] The technical problem to be solved by the present invention is how to obtain a repeatable flow development state in the measurement section while ensuring a low pressure drop, and at the same time take into account the sealing of the chip installation and the consistency of the flow field. In order to overcome the defects of the prior art (or related art) mentioned above, the present invention provides a low pressure drop flow channel assembly for thermal flow sensor chips.

[0007] This invention provides a low-pressure drop flow channel assembly for a thermal flow sensor chip, comprising a flow channel assembly, a sensor chip assembly, and an external measurement circuit. The flow channel assembly includes a lower base, an intermediate sandwich plate, and an upper cover plate stacked sequentially. The top of the upper cover plate has an inlet connector and an outlet connector. The intermediate sandwich plate has a vertically arranged inlet flow conditioning section connected to the inlet connector and an outlet flow conditioning section connected to the outlet connector. The top of the lower base has a downstream section connected to the inlet flow conditioning section and a measurement section connected to the outlet flow conditioning section. The downstream section and the measurement section are connected. The measurement section has a chip mounting position. The sensor chip assembly includes a thermal flow sensor chip and a flexible interconnect electrically connected to the thermal flow sensor chip. The thermal flow sensor chip is disposed on the chip mounting position. A wiring structure is sandwiched between the intermediate sandwich plate and the lower base. The flexible interconnect is led out through the wiring structure and electrically connected to the external measurement circuit.

[0008] The low-pressure drop flow channel assembly for thermal flow sensor chips of the present invention has the following advantages compared with the prior art: In this invention, a clamping stacked structure consisting of a lower base, an intermediate sandwich plate, and an upper cover plate is used to seal the connection between the three layers, meeting the basic airtightness requirements. Furthermore, as a base structure, it allows operators to install inlet and outlet flow conditioning sections on the intermediate sandwich plate, and a co-current section and a measurement section on the lower base, thereby achieving precise shaping of the internal flow channels. Simultaneously, the vertically positioned inlet flow conditioning section provides initial rectification of the incoming flow, and combined with the stable and smooth flow channel provided by the co-current section, the flowing gas reaches a repeatable and controlled development state before reaching the measurement section, significantly improving the consistency of the flow field in the measurement section, thus enhancing the calibration repeatability and measurement accuracy of the thermal flow sensor chip.

[0009] In one possible implementation, both the inlet flow conditioning section and the outlet flow conditioning section are flow channels with a cross-sectional area that continuously increases from top to bottom in the vertical direction.

[0010] Compared with existing technologies, the above technical solution can avoid flow separation and local eddies caused by abrupt changes in cross-section in traditional flow channels by setting a flow channel structure with a continuously increasing cross-sectional area from top to bottom. This makes the flow of gas smoother when entering and leaving the measurement section area, which not only further reduces flow resistance and overall pressure drop, but also suppresses the generation of deflection and secondary flow, and improves flow field stability.

[0011] In one possible implementation, the inlet flow conditioning section and the downstream section are connected by an inlet-side smooth transition section, and the outlet flow conditioning section and the measurement section are connected by an outlet-side smooth transition section.

[0012] In one possible implementation, both the inlet-side smooth transition section and the outlet-side smooth transition section are arc-shaped flow channels.

[0013] Compared with existing technologies, the above-mentioned technical solution can effectively eliminate sharp or right-angle turns at the flow channel bends by using an arc-shaped flow channel as a smooth transition structure, which greatly reduces local energy loss. This design not only reduces the overall pressure drop of the device and avoids disturbance to the upstream gas supply, but also prevents turbulence induced by geometric changes, ensuring the stability and consistency of heat transfer boundary conditions within the measurement section.

[0014] In one possible implementation, the chip mounting position is a stepped groove or an embedded groove, and the thermal flow sensor chip is fixed to the bottom of the stepped groove or the embedded groove.

[0015] Compared with existing technologies, the above-mentioned technical solution can achieve precise installation and positioning of the thermal flow sensor chip through stepped grooves or embedding grooves, ensuring that the measuring surface of the thermal flow sensor chip is flush or nearly flush with the inner wall of the measuring section. This flush installation method eliminates the steps and gaps caused by the protrusion or depression of the thermal flow sensor chip, avoids local turbulence and additional energy loss, and at the same time enables the thermal flow sensor chip to obtain stable and consistent convective heat transfer boundary conditions, which is beneficial to improving the repeatability and long-term stability of the measurement.

[0016] In one possible implementation, sealing structures are provided between the upper cover plate and the intermediate interlayer plate, and between the intermediate interlayer plate and the lower base, respectively, to seal the gap between the upper cover plate and the intermediate interlayer plate and the gap between the intermediate interlayer plate and the lower base.

[0017] Compared with existing technologies, the above technical solution can ensure the airtightness of the flow channel assembly after clamping and fixing by setting a sealing structure at the joint surface of the clamping stacked structure, preventing leakage of flowing gas under high or low pressure conditions, thus ensuring measurement accuracy and improving the operational reliability of the device under complex conditions.

[0018] In one possible implementation, the sealing structure may be any one of an O-ring, a gasket, or a sealant layer.

[0019] In one possible implementation, the cable outlet structure is a cable outlet groove, and the flexible interconnect is led out from the groove of the cable outlet groove. The groove of the cable outlet groove is filled with sealing material or is provided with a pressing cover plate to fix the flexible interconnect.

[0020] Compared with existing technologies, the above-mentioned technical solution can solve the sealing problem when flexible interconnects are led out by combining the cable outlet groove with sealing materials or pressing cover plates, preventing gas leakage from the gaps in the cable leads; at the same time, this structure can provide stress relief for flexible interconnects, avoid the failure of thermal flow sensor chip connection due to external force pulling, and improve the reliability of electrical connection and the sealing durability of the device.

[0021] In one possible implementation, the inlet connector and the outlet connector are any one of threaded connectors, inverted tapered sealing connectors, ferrule connectors, and quick-connect connectors.

[0022] Compared with existing technologies, the above technical solution can improve the compatibility and flexibility of the device's connection with external main channels by setting up a variety of standardized connector types, which facilitates quick installation and replacement, while ensuring the sealing reliability of the connectors. It is suitable for precise gas flow measurement and online monitoring in different industrial application scenarios.

[0023] In one possible implementation, the lower base, the intermediate interlayer plate, and the upper cover plate are sequentially threaded together and fixed.

[0024] Compared with existing technologies, the above technical solution can use fasteners to fix the three-layer structure, which can achieve stable clamping and precise alignment. This ensures that the internal flow channels do not misalign during assembly and is easy to disassemble and maintain. This mechanical fixing method, combined with the sealing structure, can maintain a stable preload during long-term use, ensuring the airtightness and structural consistency of the internal flow channels, which is conducive to achieving process consistency in mass production. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the exploded structure of the present invention; Figure 3 This is a schematic cross-sectional view of the internal flow channel of the present invention along the main flow direction; Figure 4 This is a schematic cross-sectional view of the measurement section of the present invention at the point where the thermal flow sensor chip passes through the thermal flow sensor chip. Figure 5 This is a pressure difference-flow rate curve comparing the structure of this invention with that of a straight-through cavity. Figure 6 This is a schematic diagram of the system composition and signal processing flow of the device of the present invention; Figure 7 A graph showing the comparison between test flow rate and calibration flow rate when a branch flow channel is connected to the main flow channel; Explanation of the numerical markings in the attached diagram: 1. Flow channel assembly; 2. Sensor chip assembly; 3. External measurement circuit; 4. Lower base; 5. Intermediate sandwich plate; 6. Upper cover plate; 7. Inlet connector; 8. Outlet connector; 9. Inlet flow conditioning section; 10. Outlet flow conditioning section; 11. Flow section; 12. Measurement section; 13. Chip mounting position; 14. Thermal flow sensor chip; 15. Flexible interconnect; 16. Outlet wiring structure; 17. Inlet-side smooth transition section; 18. Outlet-side smooth transition section; 19. Sealing structure; 20. Fasteners. Detailed Implementation

[0026] First, those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0028] See Figures 1-4 This invention discloses a low-pressure drop flow channel assembly for a thermal flow sensor chip, including a flow channel assembly 1, a sensor chip assembly 2, and an external measurement circuit 3. The flow channel assembly 1 includes a lower base 4, an intermediate sandwich plate 5, and an upper cover plate 6 stacked sequentially. The top of the upper cover plate 6 has an inlet connector 7 and an outlet connector 8. The intermediate sandwich plate 5 has a vertically arranged inlet flow conditioning section 9 connected to the inlet connector 7 and a vertically arranged outlet flow conditioning section 10 connected to the outlet connector 8. The top of the lower base 4 has a section connected to the inlet flow conditioning section 9. The downstream section 11 is connected to the outlet flow conditioning section 10, and the measuring section 12 is connected to the downstream section 11 and the measuring section 12. The measuring section 12 is provided with a chip mounting position 13. The sensor chip assembly 2 includes a thermal flow sensor chip 14 and a flexible interconnect 15 electrically connected to the thermal flow sensor chip 14. The thermal flow sensor chip 14 is arranged on the chip mounting position 13. A wiring structure 16 is sandwiched between the intermediate sandwich plate 5 and the lower base 4. The flexible interconnect 15 is led out through the wiring structure 16 and electrically connected to the external measuring circuit 3.

[0029] In this embodiment of the invention, the downstream section 11 is a straight main channel with a basically constant cross-section, and its length is a settable parameter. In specific implementation, the length of the downstream section can be configured by replacing the intermediate sandwich plate 5 or the flow channel structure on the lower base 4 with different lengths to adapt to different flow ranges and installation space requirements. For example, if the overall size of the intermediate sandwich plate 5 is enlarged proportionally, then the overall size of the downstream section 11 is also enlarged proportionally. Or, if only the length of the intermediate sandwich plate 5 is increased, then the length of the downstream section 11 can be increased according to the ratio of the increased length to the original length. The downstream section 11 is used to provide a controllable flow development length before the gas enters the measuring section 12, so that the velocity profile and boundary layer evolution reach a repeatable controlled development state, thereby improving measurement repeatability. In this embodiment, the downstream section 11 and the measuring section 12 can actually be combined to form a complete flow channel, and the gas between the two is directly connected.

[0030] In this embodiment of the invention, both the inlet flow conditioning section 9 and the outlet flow conditioning section 10 are flow channels with cross-sections that change continuously from small to large in the vertical direction. This continuously changing structure can adopt a smooth transition cavity form that gradually expands or contracts, so that the gas avoids flow separation and local eddies caused by sudden expansion or contraction when flowing in and out, effectively reducing local energy loss at the inlet and outlet, and suppressing the generation of deflection and secondary flow.

[0031] In this embodiment of the invention, the inlet flow conditioning section 9 and the downstream section 11 are connected by an inlet-side smooth transition section 17, and the outlet flow conditioning section 10 and the measurement section 12 are connected by an outlet-side smooth transition section 18. Both the inlet-side smooth transition section 17 and the outlet-side smooth transition section 18 are arc-shaped flow channels. In specific implementation, the arc-shaped flow channel can adopt a continuous curved surface transition or a rounded corner transition structure, so that the internal flow channel has no sudden expansion, sudden contraction or sharp angle / right angle bend in the transition area, further reducing local energy loss, reducing overall pressure drop, and preventing the turbulence induced by geometrical abrupt changes from interfering with the flow field of the measurement section 12.

[0032] In this embodiment of the invention, the chip mounting position 13 adopts a stepped groove or an embedded groove, and the thermal flow sensor chip 14 is fixed to the bottom of the stepped groove or embedded groove. During specific assembly, the thermal flow sensor chip 14 can be fixed in the chip mounting position 13 by an adhesive layer, a clamping structure or a positioning and limiting structure, and the measuring surface of the thermal flow sensor chip 14 is kept flush or nearly flush with the inner wall of the measuring section 12, thereby eliminating the steps and gaps formed by the protrusion or depression of the thermal flow sensor chip 14, avoiding local turbulence and additional energy loss, and ensuring that the thermal flow sensor chip 14 obtains stable and consistent convective heat transfer boundary conditions.

[0033] In this embodiment of the invention, a sealing structure 19 is provided between the upper cover plate 6, the intermediate interlayer plate 5, and the lower base 4. The sealing structure 19 adopts any one of O-rings, gaskets, and sealing adhesive layers. In actual implementation, sealing grooves can be opened at the joint surfaces of each layer, and O-rings or gaskets can be embedded therein. After being clamped by fasteners 20, an airtight seal is achieved. The sealing adhesive layer can be used as an auxiliary or alternative method to further improve the sealing reliability and prevent gas leakage under positive or negative pressure conditions.

[0034] In this embodiment of the invention, the outgoing structure 16 is an outgoing groove, and the flexible interconnect 15 is led out from the groove. The groove is filled with sealing material or a pressing cover plate is provided to fix the flexible interconnect 15. Specifically, the outgoing groove can be opened at the joint surface between the intermediate sandwich plate 5 and the lower base 4. After the flexible interconnect 15 is led out through the outgoing groove, it is gas-tightened by filling with sealing materials such as epoxy resin, or fixed and sealed by pressing cover plate and elastic gasket. At the same time, it provides stress relief for the flexible interconnect 15 and avoids the failure of the solder joints of the thermal flow sensor chip 14 due to external pulling.

[0035] In this embodiment of the invention, the inlet connector 7 and the outlet connector 8 are any one of threaded connectors, inverted cone sealing connectors, compression fittings, and quick-connect connectors. The above connector types can be flexibly selected according to the application scenario, which facilitates a fast and reliable connection with the external main channel and ensures the sealing performance at the connector.

[0036] In this embodiment of the invention, multiple fasteners 20 are inserted between the lower base 4, the intermediate interlayer plate 5, and the upper cover plate 6 for fixation. Specifically, fastener 20 holes are opened on each layer plate, and fasteners 20 such as bolts and screws are inserted and locked to achieve precise alignment and stable clamping of the three-layer structure, which not only ensures the assembly accuracy of the internal flow channel, but also facilitates disassembly, maintenance and mass production.

[0037] See Figure 6 In this embodiment of the invention, the external measurement circuit 3 is electrically connected to the sensor chip assembly 2 and is used to drive and acquire signals from the thermal flow sensor chip 14 and output the flow result. The external measurement circuit 3 can adopt a constant temperature drive or a constant current drive: in the constant temperature drive, the external measurement circuit 3 adjusts the heating power in a closed loop according to the temperature / resistance signal of the thermal flow sensor chip 14 to keep the overheating temperature difference within the set range, and converts the required power or bridge output into flow rate.

[0038] In this embodiment of the invention, the working process of the device is as follows: Gas enters the flow channel assembly 1 from an external gas source through the inlet connector 7. It first flows through the inlet flow conditioning section 9, where it achieves preliminary rectification and homogenization under the action of the flow channel structure with continuously changing cross-section. Then, it enters the downstream section 11 through the inlet-side smooth transition section 17, where it fully develops in the straight mainstream channel with a basically constant cross-section, forming a repeatable flow state. Next, it enters the measurement section 12, where it undergoes forced convection heat exchange with the thermal flow sensor chip 14, which is flush with the chip mounting position 13. The electrical signal output by the thermal flow sensor chip 14 is led out through the flexible interconnect 15 and sent to the external measurement circuit 3 for driving, acquisition, and conversion, and finally outputs the flow result. Finally, the gas flows out through the outlet-side smooth transition section 18 and the outlet flow conditioning section 10, and exits through the outlet connector 8, completing the measurement process.

[0039] In this embodiment of the invention, to verify the low voltage drop effect of the invention, such as... Figure 5 As shown, under the same flow conditions, the pressure difference-flow rate curve of the device of the present invention is generally lower than that of the simulation structure of the straight cavity, indicating that the device of the present invention can effectively reduce local losses and reduce overall pressure drop through the design of the smooth transition section, flow conditioning section, co-flow section 11, and measurement section 12. To verify the applicability and measurement consistency of the branch flow channel connecting to the main flow channel, as shown... Figure 7 As shown, by comparing the results of test 1 and test 2 with the calibration values, it can be seen that under the condition that the measurement section 12 is connected to the outlet flow conditioning section 10 and the downstream section 11 is connected to the inlet flow conditioning section 9, the test flow rate and the calibration flow rate have good consistency, and the repeated test results are close, indicating that the device of the present invention has good measurement stability and repeatability under the connected use conditions.

[0040] In other embodiments of this invention, the inlet flow conditioning section 9 and the outlet flow conditioning section 10 may adopt different gradient shapes and transition curvatures; the length of the downstream section 11 may be set according to the target flow range and device size; the cross-sectional shape and size of the measuring section 12 may also be adjusted according to the size of the thermal flow sensor chip 14, flush installation requirements, and pressure drop target; the sealing structure 19 may adopt different cross-sectional forms or multiple sealing methods; the outgoing cable structure 16 may be arranged equivalently according to the size and lead-out direction of the flexible interconnect 15. The above changes do not constitute a change to the principle of this invention.

[0041] In the description of this invention, the references to "one embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0042] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A low-pressure drop flow channel assembly for a thermal flow sensor chip, comprising a flow channel assembly (1), a sensor chip assembly (2), and an external measurement circuit (3), characterized in that, The flow channel assembly (1) includes a lower base (4), an intermediate sandwich plate (5), and an upper cover plate (6) stacked in sequence. The top of the upper cover plate (6) is provided with an inlet connector (7) and an outlet connector (8). The intermediate sandwich plate (5) is provided with an inlet flow conditioning section (9) vertically arranged and connected to the inlet connector (7) and an outlet flow conditioning section (10) vertically arranged and connected to the outlet connector (8). The top of the lower base (4) is provided with a downstream section (11) connected to the inlet flow conditioning section (9) and a measuring section (12) connected to the outlet flow conditioning section (10). The downstream section (11) and the measurement section (12) are connected. The measurement section (12) is provided with a chip mounting position (13). The sensor chip assembly (2) includes a thermal flow sensor chip (14) and a flexible interconnect (15) electrically connected to the thermal flow sensor chip (14). The thermal flow sensor chip (14) is arranged on the chip mounting position (13). A wire outlet structure (16) is sandwiched between the intermediate sandwich plate (5) and the lower base (4). The flexible interconnect (15) is led out through the wire outlet structure (16) and electrically connected to the external measurement circuit (3).

2. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, Both the inlet flow conditioning section (9) and the outlet flow conditioning section (10) are flow channels whose cross-sectional area continuously increases from top to bottom in the vertical direction.

3. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, The inlet flow conditioning section (9) and the downstream section (11) are connected by an inlet-side smooth transition section (17), and the outlet flow conditioning section (10) and the measurement section (12) are connected by an outlet-side smooth transition section (18).

4. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 3, characterized in that, Both the inlet-side smooth transition section (17) and the outlet-side smooth transition section (18) are arc-shaped flow channels.

5. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, The chip mounting position (13) adopts a stepped groove or an embedded groove, and the thermal flow sensor chip (14) is fixed to the bottom of the stepped groove or the embedded groove.

6. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, Sealing structures (19) are provided between the upper cover plate (6) and the intermediate interlayer plate (5), and between the intermediate interlayer plate (5) and the lower base (4) to seal the gap between the upper cover plate (6) and the intermediate interlayer plate (5) and the gap between the intermediate interlayer plate (5) and the lower base (4).

7. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 6, characterized in that, The sealing structure (19) can be any one of O-rings, gaskets, or sealant layers.

8. The low-pressure drop channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, The cable outlet structure (16) is a cable outlet groove, and the flexible interconnect (15) is led out from the groove of the cable outlet groove. The groove of the cable outlet groove is filled with sealing material or is provided with a pressing cover plate to fix the flexible interconnect (15).

9. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, The inlet connector (7) and the outlet connector (8) are any one of the following: threaded connector, inverted cone sealing connector, ferrule connector, quick-connect connector.

10. The low-pressure drop flow channel assembly for a thermal flow sensor chip according to claim 1, characterized in that, Multiple fasteners (20) are threadedly connected and fixed by passing through the lower base (4), the intermediate interlayer plate (5), and the upper cover plate (6) in sequence.

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