A pressure sensor system

Abstract

The application discloses a pressure sensor system, which mainly comprises a MEMS pressure sensor module and a connector member. The MEMS pressure sensor module is mainly composed of a MEMS pressure sensor chip and a signal conditioning chip on a ceramic substrate, and a complete through hole is arranged below the ceramic substrate, the MEMS pressure sensor chip is communicated with the hole, the connector member provides pressure for the MEMS pressure sensor module through the through hole of the ceramic substrate, and the output signal of the MEMS pressure sensor module is filtered and processed through a single-chip microcomputer, so that the performance of the pressure sensor system is improved. The ceramic substrate and the protective cover of the MEMS pressure sensor module improve the mechanical strength and insulation performance compared with traditional pressure sensors, and the pressure-sensitive element and the test circuit are combined into a module, so that the overall size of the system is reduced, and the reliability of the system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro-electro-mechanical system (MEMS), in particular to a pressure sensor system. BACKGROUND

[0002] The pressure sensor is a device for converting pressure into pneumatic or electrical signal for control and remote transmission, which includes pressure element and control circuit and other components, the traditional pressure sensor is generally designed to separate the pressure element and the control circuit from each other, so that the overall volume of the sensor is large, the price is high, the reliability is poor, and it is difficult to adapt to the development of industrial production demand.

[0003] The pressure sensor system based on micro-electro-mechanical system (MEMS) technology can solve these problems, the volume of MEMS device is small, the size of general MEMS sensor is measured in microns, the mechanical parts after miniaturization have the advantages of small inertia, high resonant frequency and short response time. And the MEMS pressure sensor can integrate the pressure element and the signal conditioning chip together, reducing the volume of the pressure sensor.

[0004] When the pressure sensor is affected by the harsh environment, the output signal is easy to fluctuate, which will affect the accuracy of the pressure sensor, and the signal conditioning chip of the current MEMS pressure sensor only has a certain calibration function, the influence of the noise signal caused by the environmental interference reduces the reliability of the pressure sensor. In view of the above problems, the following proposes a solution. SUMMARY

[0005] The purpose of the present application is to provide a pressure sensor system with the advantages of high integration and high reliability.

[0006] The above technical purpose of the present application is realized by the following technical scheme:

[0007] The MEMS pressure sensor chip and the signal conditioning chip are integrated on the ceramic substrate circuit to form a MEMS pressure sensor module;

[0008] The ceramic substrate circuit is composed of printed circuit and alumina ceramic material, which is used to connect the circuit;

[0009] The protective cover of the MEMS pressure sensor module is made of alumina ceramic material, and there is a through hole in the center position to connect the ceramic substrate circuit with the external environment;

[0010] The specific manufacturing steps of the MEMS pressure sensor module in the present application are:

[0011] S1: processing the ceramic substrate circuit, gold plating at the pin and wire;

[0012] S2: Welding the MEMS pressure sensor chip filter capacitor on the ceramic substrate circuit;

[0013] S3: Bonding the signal conditioning chip on the ceramic substrate circuit;

[0014] S4: Wire bonding the MEMS pressure sensor and the signal conditioning chip

[0015] S5: Protecting the wire bonding site with silicone gel;

[0016] S6: Installing the ceramic protective cover on the ceramic substrate circuit.

[0017] The upper part of the component connects the power supply pins and signal pins of the pressure sensor module to the outside world through spring probes, PCB circuit boards, and terminal connectors.

[0018] The lower part of the component has a groove at the threaded part, which connects the space containing the pressure sensor module to the outside environment;

[0019] The lower part of the component has threads, making it easy to install the pressure sensor on other devices;

[0020] The upper part of the component has spring probes that can be stretched and retracted to make electrical connections with the pressure sensor module;

[0021] The connector component has a cavity inside to accommodate the pressure sensor module;

[0022] The cavity in the connector component has grooves on the top and bottom to install rubber rings;

[0023] The connector component holds the pressure sensor module in place and provides a seal through the rubber rings installed on the top and bottom of the cavity;

[0024] The middle collar of the connector component has knurling for anti-slip function, making it easy to remove the pressure sensor module;

[0025] The crossbeams on both sides of the upper part of the component are used to cooperate with the lower part to fix and prevent damage to the pressure sensor module during rotation;

[0026] The cavity in the lower part of the component that holds the pressure sensor module has cylindrical grooves at the four corners, making it easy to remove the pressure sensor module;

[0027] The upper part of the component has a groove channel that connects the pressure sensor module to the outside environment;

[0028] The upper part of the component has a through hole through which the spring probes pass to contact the pins of the pressure sensor module;

[0029] The connector component has a single-chip microcomputer filter module attached to it, which receives signals from the MEMS pressure sensor module through spring probes and outputs them through terminal connectors.

[0030] The advantages of the present application are:

[0031] The MEMS pressure sensor module integrates the MEMS pressure sensor chip and the signal conditioning chip on the ceramic substrate, which reduces the volume of the pressure sensor, has high integration, and has higher reliability and better safety compared with traditional pressure sensors.

[0032] The substrate and the protective cover of the MEMS pressure sensor module are both alumina ceramic materials, which have better mechanical strength, insulation and corrosion resistance compared with traditional pressure sensors.

[0033] The MEMS pressure sensor module adopts IIC interface to output digital signals, and the built-in signal conditioning chip can output pressure data and temperature data, which is more comprehensive than the traditional pressure sensor that can only provide pressure data.

[0034] The single-chip microcomputer in the connector can perform algorithm calibration or filtering processing on the output signals of the MEMS pressure sensor module, further improving the performance of the sensor system. Moreover, the single-chip microcomputer does not directly contact the external environment, and has high reliability. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is an overall appearance schematic diagram of the pressure sensor system of the embodiment;

[0036] Figure 2 It is a lower part bottom view of the component of the embodiment;

[0037] Figure 3 It is an appearance schematic diagram of the pressure sensor module of the embodiment;

[0038] Figure 4 It is an internal structure schematic diagram of the pressure sensor module of the embodiment;

[0039] Figure 5 It is a structure schematic diagram of the upper part of the component of the embodiment;

[0040] Figure 6 It is an installation position schematic diagram of the single-chip microcomputer filtering module of the embodiment;

[0041] Figure 7 It is an assembly schematic diagram of the MEMS pressure sensor module and the lower part of the component of the embodiment;

[0042] Figure 8 It is a structure schematic diagram of the lower part of the component of the embodiment;

[0043] Figure 9 It is a sectional view of the pressure sensor system of the embodiment;

[0044] Figure 10 The schematic diagram of the pressure sensor module of the embodiment is connected with the single-chip microcomputer.

[0045] The figure mark: 1, the terminal; 2, the collar; 26, the upper thread; 28, the PCB round plate; 29, the spring probe; 3, the component upper part; 30, the through hole one; 31, the MEMS pressure sensor module; 4, the component lower part; 5, the knurl; 6, the lower thread; 7, the through hole two; 8, the ceramic substrate circuit; 9, the pin; 10, the protective cover; 11, the through hole three; 12, the MEMS pressure sensor chip; 13, the filter capacitor; 14, the signal conditioning chip; 15, the sealed chamber; 16, the rubber ring; 19, the single-chip microcomputer. DETAILED DESCRIPTION

[0046] The following description is only the preferred embodiment of the present application, the protection scope is not limited to the embodiment only, and the technical scheme belonging to the idea of the present application should belong to the protection scope of the present application.

[0047] The pressure sensor is a kind of sensor capable of measuring the pressure of gas or liquid, the pressure sensor system provided by the present application integrates the MEMS pressure sensor chip 12 and the signal conditioning circuit 14 on the ceramic substrate circuit 8, reduces the volume of the pressure sensor, and strengthens the temperature resistance of the system due to the small thermal expansion coefficient of the ceramic. The MEMS pressure sensor module 31 and the connector component are assembled to constitute the pressure sensor system, the pressure to be measured acts on the back cavity of the MEMS pressure sensor chip 12 through the through hole 7 of the connector component and the through hole 30 at the bottom of the MEMS pressure sensor module 31, and the pressure sensor system outputs the pressure signal.

[0048] Figure 1 It is the appearance of the pressure sensor system, the terminal 1 is provided with power supply for the pressure sensor system and receives the signal of the pressure sensor, and the connector component is assembled by the collar 2 to assemble the component upper part 3 and the component lower part 4. The knurl 5 is arranged on the side of the collar 2, which plays the role of anti-skid when the pressure sensor is disassembled. The lower end part 4 is provided with the thread 6 and the regular hexagonal column 25, which facilitates the pressure sensor system to be installed on other equipment.

[0049] Figure 2 It is the bottom view of the pressure sensor system, the through hole 7 is arranged in the center of the component lower part 4, which provides the pressure for the pressure sensor module 31.

[0050] Figure 3This is an external view of the MEMS pressure sensor module 31. Its bottom is a ceramic substrate circuit 8, with pins 9 that provide power to the pressure MEMS sensor module 31 and output pressure sensor signals. A ceramic cover 10 is located above the ceramic substrate circuit 8, protecting critical components. The ceramic cover 10 also has a through hole 11 in its center, allowing the front of the MEMS pressure sensor module to communicate with the external environment.

[0051] Figure 4 for Figure 3 After removing the ceramic protective cover 10, the internal structure of the ceramic substrate circuit 8 shows that the MEMS pressure sensor chip 12 and the filter capacitor 13 are soldered onto the ceramic substrate circuit 8, and the signal conditioning chip 14 is mounted on the substrate using H2OE two-component conductive silver paste. The signal conditioning chip 14 and the MEMS pressure sensor chip 12 are mounted together on the ceramic substrate circuit 8 to power the MEMS pressure sensor chip 12 and to amplify and convert the analog output signal of the MEMS pressure sensor 12 into an IIC signal after digital-to-analog conversion.

[0052] On the ceramic substrate circuit 8, the 0.1uF capacitor 13 primarily filters out noise and high-frequency components in the power supply, making the power supply closer to an ideal voltage source. The MEMS pressure sensor chip 12 uses a back-pressure type piezoresistive pressure sensor. The signal conditioning chip 14 uses the ST015, a dedicated pressure sensor conditioning chip; the ST015 chip incorporates a temperature sensor. Figure 4 Since the signal conditioning chip 14 and the MEMS pressure sensor chip 12 are located close to each other, the temperature data of the signal conditioning chip 14 can be assumed to be the temperature data of the sensor chip 12. Module 31 outputs pressure and temperature signals through its internal IIC interface connected to the ST015 chip 14.

[0053] Figure 5 The upper part 3 of the component has a chamber 15 in the middle to accommodate the MEMS pressure sensor module 31 and an arc-shaped groove 17 for mounting the rubber ring 16. There are crossbeams 18 on both sides for fixing the position. The groove 20 connects the chamber 15 to the external environment to prevent internal pressure from affecting the performance of the pressure sensor system.

[0054] Figure 6 The mounting position of the microcontroller 19 on the PCB circular board 28 is shown. The circuit on the PCB circular board 28 connects the spring probe 29, the microcontroller 19, and the terminal block 1. After the spring probe 29 contacts the module 31, the output signal of the module 31 is transmitted to the microcontroller 19 through the spring probe 29. Then the microcontroller 19 sends out the processed signal through the terminal block 1.

[0055] Figure 7For the installation of MEMS pressure sensor module 31 in the lower part 4 of the structure, the cylindrical groove 21 is used to determine the orientation of the MEMS pressure sensor module 31. The groove 22 on both sides of the lower part 4 is complementary to the crossbeam 18, which can fix the relative position of the upper and lower parts of the connector structure. The four corners of the MEMS pressure sensor module 31 have cylindrical grooves 23 to prevent the MEMS pressure sensor module 31 from being stuck during disassembly.

[0056] Figure 8 For the lower part 4 of the structure in the pressure sensor system, there is an arc-shaped groove 17 in the center position for installing the rubber ring 16, which contains the cavity 15 of the MEMS pressure sensor module 31. The side of the lower part 4 has a groove 24 for connecting the external environment with the cavity 15. The regular hexagonal column 25 of the lower part 4 facilitates the installation of the pressure sensor system on other equipment.

[0057] Figure 9 For the cross-sectional view of the pressure sensor system. The MEMS pressure sensor module 31 is elastically clamped in the connector structure by the upper and lower nitrile rubber rings 16 with an outer diameter of 7mm and a wire diameter of 2.4mm Figure 9 The rubber ring 16 installed in the lower part 4 of the structure seals between the through hole 30 at the bottom of the MEMS pressure sensor module 31 and the through hole 7 of the lower part 4, preventing leakage. The bottom groove 27 of the cavity 15 of the lower part 4 can avoid the circuit part of the MEMS pressure sensor module 31 from contacting the lower part 4 and causing short circuit. The terminal 1 contacts the pin 9 of the MEMS pressure sensor module 31 through the PCB round plate 28 and the spring probe 29 Figure 9 The function of the PCB round plate 28 is to connect the four spring probes 29 and the terminal 1. The groove 24, the groove 20 and the through hole 11 of the ceramic cover 10 connect the MEMS pressure sensor module 31 with the external environment, preventing the generation of internal pressure affecting the performance of the pressure sensor. The lower end part 4 has a through hole 7 in the center, which provides air pressure for the pressure sensor module 31.

[0058] Figure 10 In the middle is the connection diagram of the MEMS pressure sensor module 31 and the single-chip microcomputer 19. The module 31 and the single-chip microcomputer 19 share the positive and negative electrodes. The single-chip microcomputer 19 receives the output signal of the module 31 through the IIC interface and processes it through filtering, and then sends it out through the serial port pins Txd and Rxd. The single-chip microcomputer used here is STC8G1K08A, which uses SOP8 packaging, has a small volume and saves space.

[0059] In the various components of the present application: the component upper portion 3 is mainly made of ULTEM1010 high-performance thermoplastic, the component lower portion 4 is mainly made of stainless steel, and the ceramic substrate circuit 8 of the MEMS pressure sensor module 31, the material design of these components enables the sensor to withstand a temperature range of-40℃ to 150℃ and has certain corrosion resistance, greatly expanding the use range of the pressure sensor system.

[0060] The above-described specific embodiments further specifically describe the technical problems solved by the present application, the technical solutions and beneficial effects. It should be understood that the above-described specific embodiments are merely specific embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pressure sensor system comprising a pressure sensor system, characterized by, The pressure sensor system comprises a MEMS pressure sensor module (31) and a connector member, the MEMS pressure sensor module (31) is connected with the connector member, the MEMS pressure sensor module (31) comprises a MEMS pressure sensor chip (12), a signal conditioning chip (14) and a ceramic substrate circuit (8), the MEMS pressure sensor chip (12) and the signal conditioning chip (14) are integrated on the ceramic substrate circuit (8), the MEMS pressure sensor module (31) further comprises four pins (9), the four pins (9) are output terminals of the MEMS pressure sensor module (31), the four pins (9) are positive, SCL, SDA and negative respectively, a sealed chamber (15) is arranged in the connector member, the sealed chamber (15) is used for accommodating the MEMS pressure sensor module (31), a rubber ring (16) is arranged in the sealed chamber (15), the rubber ring (16) is arranged at the upper end and the lower end of the MEMS pressure sensor module (31) and is used for sealing the MEMS pressure sensor module (31), a single-chip microcomputer (19) is arranged in the connector member, the single-chip microcomputer (19) is connected with the output terminals of the MEMS pressure sensor module (31), the single-chip microcomputer (19) is used for filtering the output signals of the MEMS pressure sensor module (31), and a wiring terminal (1) is connected with the output end of the single-chip microcomputer (19), the wiring terminal (1) is used for connecting external equipment and transmitting the filtered signals to the external equipment. The output of the MEMS pressure sensor module (31) is a digital signal, an IIC interface is adopted, the single-chip microcomputer (19) reads the pressure signals and temperature signals of the pressure sensor through the IIC interface of the MEMS pressure sensor module (31) and performs filtering processing. The connector member comprises a member upper portion (3) and a member lower portion (4), the member upper portion (3) and the member lower portion (4) are fixedly connected, a sleeve ring (2) is sleeved and fixed on the outer side wall of the member upper portion (3), the member upper portion (3) is provided with a PCB round plate (28) and a spring probe (29), the single-chip microcomputer (19) is fixed to the lower end face of the PCB round plate (28), the spring probe (29) is fixed to the lower end face of the PCB round plate (28), and the spring probe (29) is electrically connected with the single-chip microcomputer (19), and the lower end of the spring probe (29) is used for connecting the pins (9) of the MEMS pressure sensor module (31), and the wiring terminal (1) is fixed to the upper end face of the PCB round plate (28).

2. A pressure sensor system according to claim 1, wherein, The sleeve ring (2) is provided with knurls (5), and the knurls (5) are used for anti-skid.

3. A pressure sensor system according to claim 1, wherein, The member lower portion (4) is provided with an upper thread (26) and a lower thread (6), the upper thread (26) is used for connecting the member upper portion (3), and the lower thread (6) is used for connecting external equipment.

4. The pressure sensor system of claim 1, wherein, The ceramic substrate is provided with a through hole one (30), the connector member is provided with a through hole two (7), the through hole one (30) and the through hole two (7) are connected, for measuring pressure, the MEMS pressure sensor module (31) is provided with a protective cover (10), the protective cover (10) is provided with a through hole three (11), the through hole three (11) is communicated with the upper part of the module and the environment, to prevent the formation of pressure in the module affecting the system performance.

5. The method of claim 1, wherein the MEMS pressure sensor module is fabricated by a method comprising: It comprises the following steps, ​ S1: making ceramic substrate circuit (8), and sinking gold in the circuit part; S2: welding MEMS pressure sensor chip (12), filter capacitor (13) on the ceramic substrate circuit (8); S3: the pressure sensor signal conditioning chip (14) is pasted on the substrate by conductive silver paste, and the silver paste is solidified at 150 DEG C for 10 minutes; S4: using wire bonder to connect MEMS pressure sensor chip (12) and signal conditioning chip (14); S5: using organic silicone gel to package all the pins (9) of MEMS pressure sensor chip (12) and signal conditioning chip (14) which are wired, to prevent the wired parts from being interfered by external vibration and causing poor contact; S6: the ceramic protective cover (10) is bonded on the ceramic substrate with glue to protect the circuit.

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