A MEMS gas mass flow controller

Abstract

This invention discloses a MEMS gas mass flow controller, comprising a detection chamber, wires, a valve, and pipes. Pipes are located at both ends of the detection chamber, with a valve connected to one side of the pipe. A MEMS sensor is located at the top of the detection chamber. An electric handle is located at the upper end of the valve, and the electric handle is connected to the MEMS sensor via wires. Several heat-insulating components are located on the outside of the pipes. Each heat-insulating component includes an outer shell and an inner shell, which are fixedly connected. An inner cavity is provided between the inner shell and the outer shell. This invention, through multi-segment vacuum heat-insulating components on the outside of the pipes, combined with the sponge layer of the outer shell for buffering and heat insulation, forms a double temperature isolation barrier, solving the problem of thermal drift of the MEMS sensor caused by sudden changes in ambient temperature. It significantly reduces the zero-point drift amplitude, thereby extending the calibration cycle, reducing the frequency of manual calibration operations, and reducing labor costs. It is particularly suitable for the harsh environment of semiconductor workshops with rapid temperature changes.

Description

Technical Field

[0001] This utility model relates to the field of gas mass flow controller technology, specifically a MEMS gas mass flow controller. Background Technology

[0002] A MEMS gas mass flow controller (MFC) is a high-precision gas flow control device based on microelectromechanical systems (MEMS) flow sensing technology, widely used in high-end industrial applications such as semiconductors, photovoltaics, biomedicine, vacuum coating, and analytical instruments. Chinese Patent No. CN202121412841.5 discloses a novel thermal gas mass flow controller, comprising a straight pipe, a filter, a sensor module, a measurement and control circuit, a solenoid valve, a gas path opening and closing component, an external interface, and a control system. A filter is horizontally laid inside the straight pipe. The sensor module is mounted on the top of the straight pipe, and the solenoid valve is mounted on the top of the straight pipe to the right of the sensor module. The output of the sensor module is connected to the input of the measurement and control circuit. The output of the measurement and control circuit is connected to the input of the gas path opening and closing component and the solenoid valve, respectively. The measurement and control circuit is connected to the control system through an external interface. The control unit of this invention uses a solenoid valve to drive a metal moving part to open or close, achieving linear regulation of the gas flow in the pipeline.

[0003] Based on the above, the inventors have discovered the following problems: The above-mentioned device can control the metal moving parts driven by the solenoid valve to open or close, thereby achieving linear regulation of the airflow in the pipeline; however, it neglects the insulation of the pipe wall of the MEMS gas mass flow controller. Since the MEMS gas mass flow controller needs to be calibrated regularly or zero-point calibrated on-site to avoid zero-point drift and accuracy degradation, especially when the ambient temperature changes too quickly, i.e., when the ambient temperature rises or falls rapidly, operators need to frequently perform calibration and zero-point calibration, which is very troublesome. Utility Model Content

[0004] The purpose of this invention is to provide a MEMS gas mass flow controller to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a MEMS gas mass flow controller, comprising a detection chamber, wires, a valve, and a pipe. The detection chamber has pipes at both ends, and a valve is connected to one side of the pipe. A MEMS sensor is provided at the top of the detection chamber. An electric handle is provided at the upper end of the valve. The electric handle is connected to the MEMS sensor via wires. Several heat insulation components are provided on the outside of the pipe.

[0006] Furthermore, the heat insulation component includes an outer shell and an inner shell, which are fixedly connected. An inner cavity is provided between the inner shell and the outer shell, and the inner cavity is a vacuum cavity.

[0007] Furthermore, one end of the cylindrical component formed by the outer shell and the inner shell is provided with a connecting groove, and the other end of the cylindrical component is provided with a retaining ring. The retaining ring is adapted to the connecting groove, and the retaining rings on different cylindrical components are engaged with the connecting groove.

[0008] Furthermore, the inner shell is coated with an adhesive layer.

[0009] Furthermore, each of the inner shell and the outer shell has a mounting plate at one end facing each other, and each pair of mounting plates has an adhesive layer at one end facing each other. The adhesive layer is Velcro, and the adhesive layers on the pair of mounting plates match each other.

[0010] Furthermore, the outer shell is provided with a sponge layer.

[0011] Compared with the prior art, the beneficial effects of this utility model are: this MEMS gas mass flow controller is reasonable and has the following advantages:

[0012] (1) By using a multi-segment vacuum insulation component on the outside of the pipe, combined with the sponge layer of the outer shell for buffering and heat insulation, a double temperature isolation barrier is formed; the vacuum cavity effectively blocks the conduction of external temperature, while the sponge layer absorbs the instantaneous temperature difference fluctuations in the environment, which greatly reduces the rate of temperature change of the gas inside the pipe; this solution completely solves the problem of thermal drift of MEMS sensors caused by sudden changes in ambient temperature, greatly compresses the zero-point drift amplitude, thereby extending the calibration cycle, reducing the frequency of manual calibration operations, reducing labor costs, and is especially suitable for the harsh environment of rapid temperature changes in semiconductor workshops;

[0013] (2) By using the quick-locking connection between the snap ring and the connecting groove, and with the Velcro adhesive layer of the mounting plate, the mechanical locking and flexible sealing assembly of the insulation components can be achieved; the installation time of the single-section cylindrical component is fast and it supports tool-free disassembly, which greatly improves the maintenance efficiency; the elastic compensation characteristics of the Velcro fill the connection gaps and can improve the vibration resistance; this design allows for the partial replacement of damaged sections, avoids the scrapping of the entire insulation layer, reduces maintenance costs, and ensures the sealing integrity of the vacuum chamber under long-term vibration conditions, thus ensuring the stability of MEMS flow control accuracy from the root. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0015] Figure 2 This is a schematic diagram of the cross-sectional structure of the present invention;

[0016] Figure 3 This is a partially exploded structural diagram of the present invention;

[0017] Figure 4 This is a cross-sectional structural diagram of the present invention;

[0018] In the diagram: 1. MEMS sensor; 2. Electric handle; 3. Valve; 4. Detection chamber; 5. Outer shell; 6. Wire; 7. Pipe; 8. Snap ring; 9. Connecting groove; 10. Mounting plate; 11. Inner cavity; 12. Adhesive layer; 13. Inner shell. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1-4 The present invention provides a technical solution as follows:

[0021] Example:

[0022] A MEMS gas mass flow controller includes a detection chamber 4, a wire 6, a valve 3, and a pipe 7. The detection chamber 4 has pipes 7 at both ends, and one side of the pipe 7 is connected to the valve 3. The top of the detection chamber 4 is provided with a MEMS sensor 1. The upper end of the valve 3 is provided with an electric handle 2. The electric handle 2 is connected to the MEMS sensor 1 through the wire 6. Several heat insulation components are provided on the outside of the pipe 7.

[0023] The aforementioned MEMS sensor 1 detects the gas flow rate, and the detected signal is transmitted through the wire 6 to drive the electric handle 2 to adjust the valve 3, thereby stabilizing the gas flow rate at the set value. The MEMS sensor 1 can adopt the thermal mass flow detection principle, and combined with the electric valve 3, it can achieve rapid response and realize high-precision, real-time gas mass flow control.

[0024] The heat insulation component includes an outer shell 5 and an inner shell 13, which are fixedly connected. An inner cavity 11 is provided between the inner shell 13 and the outer shell 5, and the inner cavity 11 is a vacuum cavity.

[0025] Since the detection accuracy of MEMS sensor 1 depends on a stable temperature environment, the insulation of detection cavity 4 and pipe 7 is crucial. The insulation component on the outside of pipe 7 can maintain the temperature stability of pipe 7, while the inner cavity 11 provides thermal insulation to reduce the impact of external ambient temperature on gas and sensor. Among them, the sponge layer has the function of auxiliary buffering and insulation, enhancing the insulation effect of the insulation component. The insulation component ensures that the thermal detection principle of MEMS sensor 1 is not affected by temperature fluctuations, thereby improving the accuracy of flow measurement and the reliability of control system.

[0026] The cylindrical component consisting of the outer shell 5 and the inner shell 13 has a connecting groove 9 at one end and a retaining ring 8 at the other end. The retaining ring 8 is adapted to and engaged with the connecting groove 9.

[0027] Alignment and locking are achieved by using the retaining ring 8 and the connecting groove 9, and the adhesive layer 12 is pressed and fixed. The operation is simple, and the detachable design extends the life of the insulation components, avoids the need to replace the entire section of pipe insulation layer due to local damage, and reduces maintenance costs.

[0028] The inner shell 13 is coated with an adhesive layer.

[0029] The cylindrical component consisting of the outer shell 5 and the inner shell 13 has a connecting groove 9 at one end and a retaining ring 8 at the other end. The retaining ring 8 is adapted to the connecting groove 9, and the retaining rings 8 on different cylindrical components are engaged with the connecting groove 9.

[0030] After the retaining ring 8 and the connecting groove 9 are mechanically connected, the adhesive layer 12 provides secondary fixation: the axial auxiliary locking can prevent the retaining ring 8 from slipping out of the connecting groove due to vibration, and the radial sealing compensation can fill the tiny gaps between the mounting plates 10 and block air convection heat dissipation.

[0031] The outer shell 5 is provided with a sponge layer.

[0032] Working principle: When the ambient temperature changes, the cylindrical component composed of the outer shell 5 and the inner shell 13 is placed over the pipe 7. The corresponding number of insulation components are combined according to the pipe 7 of different lengths. The cylindrical components are connected by the design of the retaining ring 8 and the connecting groove 9, thereby completely covering the surface of the pipe 7. Then, the cylindrical components are fixed to the pipe 7 by a pair of adhesive layers 12. The inner cavity 11 is designed as a vacuum cavity, which can isolate the ambient temperature and prevent the temperature of the pipe 7 and its interior from being affected by the external ambient temperature. The surface sponge layer can prevent the pipe 7 from colliding, thereby preventing damage to the MEMS sensor 1 and the valve 3.

[0033] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A MEMS gas mass flow controller, comprising a detection chamber (4), a wire (6), a valve (3), and a pipe (7), characterized in that: The detection chamber (4) has pipes (7) at both ends. One side of the pipe (7) is connected to a valve (3). The top of the detection chamber (4) is equipped with a MEMS sensor (1). The upper end of the valve (3) is equipped with an electric handle (2). The electric handle (2) is connected to the MEMS sensor (1) through a wire (6). Several heat insulation components are provided on the outside of the pipe (7).

2. The MEMS gas mass flow controller according to claim 1, characterized in that: The heat insulation component includes an outer shell (5) and an inner shell (13), the outer shell (5) and the inner shell (13) are fixedly connected, and an inner cavity (11) is provided between the inner shell (13) and the outer shell (5), the inner cavity (11) being a vacuum cavity.

3. A MEMS gas mass flow controller according to claim 2, characterized in that: The cylindrical component consisting of the outer shell (5) and the inner shell (13) has a connecting groove (9) at one end and a retaining ring (8) at the other end. The retaining ring (8) is adapted to the connecting groove (9), and the retaining ring (8) on different cylindrical components is engaged with the connecting groove (9).

4. A MEMS gas mass flow controller according to claim 3, characterized in that: The inner shell (13) is coated with an adhesive layer.

5. A MEMS gas mass flow controller according to claim 4, characterized in that: The inner shell (13) and the outer shell (5) are each provided with a mounting plate (10) at the opposite end. Each pair of mounting plates (10) is provided with an adhesive layer (12) at the opposite end. The adhesive layer (12) is Velcro, and the adhesive layers (12) on the pair of mounting plates (10) match.

6. A MEMS gas mass flow controller according to claim 5, characterized in that: The outer shell (5) is provided with a sponge layer.

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