A MEMS vibration and temperature composite sensor

Abstract

The present invention provides a MEMS vibration and temperature composite sensor, which belongs to the field of sensor technology, and includes a sensor body and a connector body. The sensor body includes a base and a shell cover, and the shell cover has a connector terminal along its axial direction; the end of the shell cover has a recessed groove, and the end of the connector terminal is located in the recessed groove; the first end of the connector body has a mounting sleeve for connecting the shell cover, and the mounting sleeve has a cavity for embedding the shell cover, and the bottom of the cavity has an extension sleeve extending toward the open end, and the extension sleeve has a lead terminal, and the extension sleeve is embedded in the recessed groove and the lead terminal extends into the extension sleeve and is connected to the connector terminal. The MEMS vibration and temperature composite sensor provided by the present invention is detachably connected to the shell cover of the connector body and the sensor body, which reduces the volume of the sensor, makes the product more convenient in production, assembly and testing, and increases the high pressure resistance and waterproof performance of the sensor.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and more specifically, relates to a MEMS vibration and temperature composite sensor. Background Art

[0002] In the design of vibration and temperature measurement and control conditions for rail transit such as high-speed rail and subway, vibration and temperature composite sensors are often used. The environmental conditions of vibration sensors require composite sensors to meet the requirements of high insulation withstand voltage (1500-4500VAC), IP68 protection level, adaptability to complex electromagnetic environments, high-strength structure, high-frequency vibration transmission and fast temperature response.

[0003] At present, most vibration sensors use piezoelectric accelerometers, and some products use external circuits with a response frequency of 0.5Hz-10000Hz. There are fewer capacitive accelerometers, and the structure of capacitive accelerometers is large and the assembly process is complex. The existing vibration sensors are integrated with the connector head, which increases the difficulty of the assembly process, and the transportation, testing, and maintenance are relatively complicated. Summary of the invention

[0004] The purpose of the present invention is to provide a MEMS vibration and temperature composite sensor, aiming to solve the problems of large volume and complex assembly process of capacitive vibration sensors.

[0005] To achieve the above object, the technical solution adopted by the present invention is: to provide a MEMS vibration and temperature composite sensor, comprising: The sensor body comprises a base and a shell cover, wherein the inner cavity of the base is provided with a circuit unit, and the circuit unit is connected with a vibration sensitive chip and a temperature probe; the shell cover is connected with the base to close the inner cavity of the base, and the shell cover has a connector terminal along its axial direction, and the connector terminal penetrates the shell cover and is connected with the circuit unit; the end of the shell cover has a sinking groove, and the end of the connector terminal is located in the sinking groove; A connector body, wherein the first end of the connector body has a mounting sleeve for connecting to the shell cover, the mounting sleeve has a cavity for embedding the shell cover, the bottom of the cavity has an extension sleeve extending toward the open end, the extension sleeve has a lead terminal, the extension sleeve is embedded in the sink groove and the lead terminal extends into the extension sleeve to be connected to the connector terminal.

[0006] As another embodiment of the present application, the sink is conical, and the inner diameter of the sink gradually decreases from the open end toward the closed section; the connector terminal is coaxial with the sink, and the end of the connector terminal is located in the sink.

[0007] As another embodiment of the present application, the lead terminal is arranged along the axial direction of the extension sleeve, the lead terminal is located in the extension sleeve, and the end of the lead terminal has a countersunk hole extending along the axial direction, and the countersunk hole is adapted to the connector terminal.

[0008] As another embodiment of the present application, the middle portion of the shell cover has an annular limiting groove, and the free end of the mounting sleeve has an annular clamping portion protruding inward, and the annular clamping portion is clamped and matched with the limiting groove.

[0009] As another embodiment of the present application, the circuit unit includes: A wiring substrate, the wiring substrate is fixed to the bottom end of the shell cover, and the wiring substrate is used to connect the connector terminals; A chip mounting substrate, the chip mounting substrate is located in the inner cavity of the base, the chip mounting substrate is longitudinally spaced apart from the wiring substrate and connected via a flexible circuit, the vibration sensitive chip and the temperature probe are connected to the chip mounting substrate; The inner cavity of the base is filled with epoxy glue, and the epoxy glue wraps the chip mounting substrate and the wiring substrate.

[0010] As another embodiment of the present application, the chip mounting substrate includes two circuit substrates, the two circuit substrates are spaced apart in the longitudinal direction, and the two circuit substrates are connected by a flexible circuit; the circuit substrate on the lower side is attached to the bottom of the base cavity, and the temperature probe extends into the embedded cavity below the base cavity, and the embedded cavity is filled with epoxy glue.

[0011] As another embodiment of the present application, the connection end of the temperature probe is connected to the circuit substrate on the upper side, and the measuring end of the temperature probe passes through the circuit substrate on the lower side and extends into the embedded cavity; a clearance hole is provided on the circuit substrate on the lower side to allow the temperature probe to pass through.

[0012] As another embodiment of the present application, the circuit substrate includes a flexible circuit layer, a copper-clad shielding layer and a hard reinforcement layer arranged in sequence from top to bottom, and the hard reinforcement layer is made of an insulating material; the welding points of the vibration sensitive chip and the welding points of the temperature probe are both located in the flexible circuit layer.

[0013] As another embodiment of the present application, the base includes: Base body; An extension part, wherein the extension part is connected to the bottom of the base body, the embedded cavity is opened in the extension part, the embedded cavity is connected to the inner cavity of the base body, and the inner diameter of the embedded cavity is smaller than the inner diameter of the inner cavity of the base body.

[0014] As another embodiment of the present application, the middle part of the inner cavity of the base body has a limiting step with the end face facing upward; the two circuit substrates are respectively located at the bottom of the inner cavity of the base body and on the limiting step, and the output ends of the two circuit substrates are located on the same side.

[0015] The beneficial effect of a MEMS vibration and temperature composite sensor provided by the present invention is that: compared with the prior art, a MEMS vibration and temperature composite sensor of the present invention realizes the electrical connection between the connector terminal and the lead terminal through the detachable connection between the shell cover of the connector body and the sensor body, thereby reducing the volume of the sensor and making the product more convenient in production, assembly and testing. In addition, the setting of the extension sleeve and the sink groove further increases the high pressure resistance and waterproof performance of the sensor, meeting the design requirements of high pressure resistance (5000V) insulation sealing and IP68 level. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a MEMS vibration and temperature composite sensor provided by an embodiment of the present invention; Figure 2 A cross-sectional view of a MEMS vibration and temperature composite sensor provided by an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a connector body provided by an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a housing cover provided by an embodiment of the present invention; Figure 5 A cross-sectional view of a housing cover provided by an embodiment of the present invention; Figure 6 A schematic diagram of the connection between the housing cover and the base provided in an embodiment of the present invention; Figure 7 A schematic diagram of the structure of a circuit unit provided by an embodiment of the present invention; Figure 8 A schematic diagram of the structure of a circuit unit provided in an embodiment of the present invention.

[0018] In the figure: 1. Connector body; 2. Mounting sleeve; 3. Shell cover; 4. Base; 5. Extension part; 6. Pressure-resistant filling layer; 7. Lead terminal; 8. Extension sleeve; 9. Connector terminal; 10. Circuit substrate; 11. Wiring substrate; 12. Temperature probe; 13. Sink; 14. Limiting groove; 15. Mounting groove; 16. Support part; 17. Embedded cavity; 18. Connection hole; 19. Flexible circuit. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] See also Figures 1 to 8 Now, a MEMS vibration and temperature composite sensor provided by the present invention is described. The MEMS vibration and temperature composite sensor comprises a sensor body and a connector body 1. The sensor body comprises a base 4 and a shell cover 3. The inner cavity of the base 4 has a circuit unit, and the circuit unit is connected with a vibration sensitive chip and a temperature probe 12; the shell cover 3 is connected to the base 4 for closing the inner cavity of the base 4, and the shell cover 3 has a connector terminal 9 along its axial direction, and the connector terminal 9 penetrates the shell cover 3 and is connected with the circuit unit; the end of the shell cover 3 has a sinking groove 13, and the end of the connector terminal 9 is located in the sinking groove 13; the first end of the connector body 1 has a mounting sleeve 2 for connecting the shell cover 3, and the mounting sleeve 2 has a cavity for embedding the shell cover 3, and the bottom of the cavity has an extension sleeve 8 extending toward the open end, and the extension sleeve 8 has a lead terminal 7, and the extension sleeve 8 is embedded in the sinking groove 13 and the lead terminal 7 extends into the extension sleeve 8 and is connected with the connector terminal 9.

[0021] Compared with the prior art, the MEMS vibration and temperature composite sensor provided by the present invention is manufactured into a two-part structure of a sensor body and a connector body 1. The electrical connection between the connector body 1 and the shell cover 3 of the sensor body is detachably connected to realize the electrical connection between the connector terminal 9 and the lead terminal 7, thereby reducing the volume of the sensor and making the product more convenient in production, assembly and testing. In addition, the provision of the extension sleeve 8 and the sink 13 further increases the high-voltage resistance and waterproof performance of the sensor, thereby meeting the design requirements of high-voltage resistance (5000V) insulation sealing and IP68 grade.

[0022] In addition, in order to adapt to the complex electromagnetic environment of rail transit, the sensor provided by the present invention adopts a signal transmission method with current (4-20mA) output, which has a strong anti-interference effect; and the internal circuit of the sensor of the present invention adds corresponding protection from the input and output, and can handle external voltage fluctuation interference through the internal secondary power supply circuit operating in a wide voltage range.

[0023] Specifically, the filling material in the shell cover 3, the filling material in the connector body 1, and the material of the extension sleeve 8 are consistent, and a high-voltage resistant elastic material is selected. This material is used to increase the high-voltage resistant protection and waterproof protection of the connection between the connector terminal 9 and the lead terminal 7. Optionally, the high-voltage resistant elastic material can be selected from high-thermal conductive carbon fiber.

[0024] The shell cover 3 is filled with the above-mentioned high-pressure resistant elastic material, and a recessed groove 13 is provided at the upper end of the internal filling layer of the shell cover 3. The connector terminal 9 penetrates the internal filling layer and extends to the inside of the recessed groove 13. The connector body 1 is also filled with the above-mentioned high-pressure resistant elastic material to form a pressure-resistant filling layer 6. An extension sleeve 8 extending downward is provided on the end face of the pressure-resistant filling layer 6 of the connector body 1. The extension sleeve 8 is also made of the above-mentioned high-pressure resistant elastic material. The lead terminal 7 is located inside the extension sleeve 8. During installation, the extension sleeve 8 extends into the recessed groove 13, and the open end of the extension sleeve 8 is sleeved on the end of the connector terminal 9. The two continue to be plugged and moved until the extension sleeve 8 is completely embedded in the recessed groove 13, and the end face of the filling layer of the shell cover 3 fits with the end face of the pressure-resistant filling layer 6 of the connector body 1. At the same time, the connector terminal 9 and the lead terminal 7 located in the extension sleeve 8 complete the plug-in connection.

[0025] The connector terminal 9 and the lead terminal 7 are connected and sealed by means of the recessed groove 13 and the extension sleeve 8. The recessed groove 13 and the extension sleeve 8 are fitted together so that the extension sleeve 8 can seal the connection between the two terminals, thereby increasing the length of the high-voltage breakdown path and further improving the pressure resistance and waterproof performance.

[0026] like Figures 2 to 4 As shown, the sink 13 is conical, and the inner diameter of the sink 13 gradually decreases from the open end toward the closed section; the connector terminal 9 is coaxial with the sink 13, and the end of the connector terminal 9 is located in the sink 13.

[0027] The sink 13 is in an inverted cone shape, and the inner diameter of the opening end of the sink 13 is larger than the inner diameter of the bottom of the sink 13 ; the connector terminal 9 in the sink 13 is located inside the sink 13 .

[0028] During installation, since the extension sleeve 8 is installed to the bottom of the sink 13, an inclined connection surface is formed between the extension sleeve 8 and the sink 13, thereby increasing the length of the high-voltage breakdown path and achieving the purpose of protecting the connection terminal.

[0029] The lead terminal 7 is arranged along the axial direction of the extension sleeve 8, the lead terminal 7 is located in the extension sleeve 8, and the end of the lead terminal 7 has a countersunk hole extending along the axial direction, and the countersunk hole is adapted to the connector terminal 9. The free end of the lead terminal 7 is located in the extension sleeve 8, the countersunk hole is arranged along the axial direction, and the inner side wall of the countersunk hole is in contact with the outer side wall of the connector terminal 9.

[0030] In some possible embodiments, see Figure 1, Figure 2 , Figure 4 and Figure 5 The middle part of the shell cover 3 has an annular limiting groove 14 , and the free end of the mounting sleeve 2 has an annular clamping portion protruding inward, and the annular clamping portion is clamped and matched with the limiting groove 14 .

[0031] The limiting groove 14 is provided in the middle of the outer side of the shell cover 3. The limiting groove 14 is an annular groove with its opening facing outward. During installation, the free end of the installation sleeve 2 is inserted from the end of the shell cover 3 until the annular clamping portion of the free end of the installation sleeve 2 enters the limiting groove 14; at this time, the extension sleeve 8 fits with the sink groove 13, and the lead terminal 7 and the connector terminal 9 are connected.

[0032] The lower end of the shell cover 3 has a mounting groove 15 for adapting the circuit unit. The connector terminal 9 longitudinally penetrates the filling layer of the shell cover 3 and extends into the mounting groove 15. The connector terminal is connected to the circuit unit in the mounting groove 15.

[0033] In some possible embodiments, see Figure 7 and Figure 8 The circuit unit includes a wiring substrate 11 and a chip mounting substrate; the wiring substrate 11 is fixed to the bottom end of the shell cover 3, and the wiring substrate 11 is used to connect the connector terminal 9; the chip mounting substrate is located in the inner cavity of the base 4, the chip mounting substrate and the wiring substrate 11 are longitudinally spaced and connected through a flexible circuit 19, and the vibration sensitive chip and the temperature probe 12 are connected to the chip mounting substrate; the inner cavity of the base 4 is filled with epoxy glue, and the epoxy glue wraps the chip mounting substrate and the wiring substrate 11.

[0034] The wiring substrate 11 of the circuit unit is bonded and fixed in the mounting groove 15 and welded to the housing cover 3. A plurality of connection holes 18 are reserved on the circuit unit, and the connection terminals penetrate through the connection holes 18 and are welded to the hole walls of the connection holes 18. The wiring substrate 11 and the chip mounting substrate are connected through a flexible circuit 19.

[0035] The bottom of the inner cavity of the base 4 is connected to a pre-buried cavity 17 opened at the bottom of the base 4 . The chip mounting substrate is located in the inner cavity of the base 4 . The temperature probe 12 connected to the chip mounting substrate extends into the pre-buried cavity 17 .

[0036] The connection end of the temperature probe 12 is connected to the upper circuit substrate 10, and the measuring end of the temperature probe 12 passes through the lower circuit substrate 10 and extends into the embedded cavity 17; a clearance hole is opened on the lower circuit substrate 10 to allow the temperature probe 12 to pass through.

[0037] Specifically, the chip mounting substrate includes two circuit substrates 10, which are spaced apart in the longitudinal direction and connected by a flexible circuit 19; the lower circuit substrate 10 is attached to the bottom of the inner cavity of the base 4, and the temperature probe 12 extends into the embedded cavity 17 below the inner cavity of the base 4, and the embedded cavity 17 is filled with epoxy glue.

[0038] Two circuit substrates 10 and one wiring substrate 11 are connected in sequence through a flexible circuit 19, and the output end of the circuit substrate 10 is located on the same side, and the input end of the circuit substrate 10 and the wiring substrate 11 are located on the same side. The flexible circuit 19 is folded in the inner cavity of the base 4, and when folded, the middle part of the flexible circuit 19 is located between two adjacent substrates and is spaced apart from both substrates.

[0039] The connection end of the temperature probe 12 is connected to the upper circuit substrate 10, and the measuring end of the temperature probe 12 passes through the lower circuit substrate 10 and extends into the embedded cavity 17; a clearance hole is opened on the lower circuit substrate 10 to allow the temperature probe 12 to pass through.

[0040] During installation, the measuring end of the temperature probe 12 is first passed through the lower circuit substrate 10 and extended into the embedded cavity 17. After the installation is completed, epoxy glue is filled into the embedded cavity 17. The epoxy glue is used to seal the temperature probe 12 to protect the temperature probe 12.

[0041] Then, the circuit substrate 10 on the lower side and the circuit substrate 10 on the upper side and the wiring substrate 11 are installed in sequence. After the installation is completed, epoxy glue is poured into the inner cavity of the base 4, and the epoxy glue completely wraps the two circuit substrates 10. Finally, the shell cover 3 is closed and laser welded to the open end of the base 4, and the wiring substrate 11 at the lower end of the shell cover 3 is in contact with the epoxy glue.

[0042] The sensor is potted with electronic epoxy glue to achieve reliable high-frequency response measurement and meet the voltage isolation requirements of strong electricity in the working environment and weak electricity inside the sensor.

[0043] Specifically, the circuit substrate 10 includes a flexible circuit layer, a copper-clad shielding layer and a hard reinforcement layer arranged in sequence from top to bottom, and the hard reinforcement layer is made of insulating material; the welding points of the vibration sensitive chip and the welding points of the temperature probe 12 are both located in the flexible circuit layer.

[0044] The flexible circuit layer of the circuit substrate 10 is a single-sided fabric, and a large area of ​​copper is coated on the bottom of the flexible circuit layer to form a copper-clad shielding layer to achieve secondary effective shielding of the internal sensitive units, and combined with a metal shielding shell to achieve a double-layer shielding protection effect.

[0045] The hard reinforcing layer is a hard circuit board material, and is connected to the copper-clad shielding layer to increase the hardness and strength of the circuit substrate 10, and facilitate the installation and clamping of the circuit substrate 10. The thickness of the hard reinforcing layer is 1 mm, and the hard reinforcing layer has an insulating characteristic, and the hard reinforcing layer isolates the copper-clad shielding layer and the base 4.

[0046] The circuit unit connects multiple circuit substrates 10 through a flexible circuit 19, and adds a copper-clad shielding layer and a hard reinforcement layer at the bottom of the circuit substrate 10. The multiple circuit substrates 10 are folded and installed, which saves installation space and facilitates product miniaturization. At the same time, it also ensures the strength and quality of the circuit substrate 10 and realizes secondary shielding.

[0047] In some possible embodiments, see Figure 6 The base 4 includes a base body and an extension portion 5, the extension portion 5 is connected to the bottom of the base body, the embedded cavity 17 is opened in the extension portion 5, the embedded cavity 17 is connected to the inner cavity of the base body, and the inner diameter of the embedded cavity 17 is smaller than the inner diameter of the inner cavity of the base body.

[0048] The base body and the extension part 5 are integrally formed. The inner cavity of the base body is a cylindrical space for installing the circuit unit. The extension part 5 has a pre-embedded cavity 17, which is connected to the inner cavity of the base body. The inner diameter of the pre-embedded cavity 17 is smaller than the inner diameter of the inner cavity of the base body, and the opening end of the pre-embedded cavity 17 has a chamfered structure, which forms a flared mouth at the opening of the pre-embedded cavity 17 to facilitate the insertion of the temperature probe 12.

[0049] The middle of the inner cavity of the base body has a limiting step with the end surface facing upward; the two circuit substrates 10 are respectively located at the bottom of the inner cavity of the base body and on the limiting step, and the output ends of the two circuit substrates 10 are located on the same side.

[0050] The inner cavity of the base body has a support portion 16 extending inwardly, the support portion 16 is an arc-shaped structure, the outer side of the support portion 16 is connected to the base body, and the upper end surface of the support portion 16 forms a limiting step. The circuit substrate 10 located at the bottom is directly placed at the bottom of the inner cavity of the base body, and the circuit substrate 10 located at the top is overlapped on the limiting step at the upper end of the support portion 16. Under the action of the support portion 16, the upper circuit substrate 10 and the lower circuit substrate 10 are spaced apart to form a folded circuit unit.

[0051] The present invention provides a MEMS vibration and temperature composite sensor, which adopts a MEMS variable capacitance accelerometer with a response frequency of 0-10000Hz and can test signals of various frequency bands such as vibration, impact, overload, etc. The sensor has the characteristics of small size, simple assembly process, high measurement accuracy, low cost, and batch production; the sensor body and the connector body 1 can be independently assembled, tested, and maintained in batches, which is conducive to promotion.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A MEMS vibration and temperature composite sensor, characterized in that: include: A sensor body comprises a base (4) and a shell cover (3); a circuit unit is provided in the inner cavity of the base (4); the circuit unit is connected to a vibration sensitive chip and a temperature probe (12); the shell cover (3) is connected to the base (4) for closing the inner cavity of the base (4); a connector terminal (9) is provided in the shell cover (3) along its axial direction; the connector terminal (9) passes through the shell cover (3) and is connected to the circuit unit; a recessed groove (13) is provided at the end of the shell cover (3); the end of the connector terminal (9) is located in the recessed groove (13); A connector body (1), wherein the first end of the connector body (1) has a mounting sleeve (2) for connecting to the shell cover (3), the mounting sleeve (2) has a cavity for embedding the shell cover (3), the bottom of the cavity has an extension sleeve (8) extending toward the open end, the extension sleeve (8) has a lead terminal (7), the extension sleeve (8) is embedded in the sink groove (13), and the lead terminal (7) extends into the extension sleeve (8) to be connected to the connector terminal (9).

2. A MEMS vibration and temperature composite sensor as claimed in claim 1, characterized in that: The sink groove (13) is conical, and the inner diameter of the sink groove (13) gradually decreases from the open end toward the closed section; the connector terminal (9) is coaxial with the sink groove (13), and the end of the connector terminal (9) is located in the sink groove (13).

3. A MEMS vibration and temperature composite sensor as claimed in claim 2, characterized in that: The lead terminal (7) is arranged along the axial direction of the extension sleeve (8), the lead terminal (7) is located in the extension sleeve (8), and the end of the lead terminal (7) has a countersunk hole extending along the axial direction, and the countersunk hole is adapted to the connector terminal (9).

4. A MEMS vibration and temperature composite sensor as claimed in claim 1, characterized in that: The shell cover (3) has an annular limiting groove (14) in the middle, and the free end of the mounting sleeve (2) has an annular clamping portion protruding inward, and the annular clamping portion is clamped and matched with the limiting groove (14).

5. A MEMS vibration and temperature composite sensor as claimed in claim 1, characterized in that: The circuit unit comprises: A wiring substrate (11), the wiring substrate (11) being fixed to the bottom end of the shell cover (3), the wiring substrate (11) being used to connect the connector terminal (9); a chip mounting substrate, the chip mounting substrate being located in the inner cavity of the base (4), the chip mounting substrate being spaced apart from the wiring substrate (11) in the longitudinal direction and connected via a flexible circuit (19), the vibration sensitive chip and the temperature probe (12) being connected to the chip mounting substrate; The inner cavity of the base (4) is filled with epoxy glue, and the epoxy glue wraps the chip mounting substrate and the wiring substrate (11).

6. A MEMS vibration and temperature composite sensor as claimed in claim 5, characterized in that: The chip mounting substrate comprises two circuit substrates (10), the two circuit substrates (10) are spaced apart in the longitudinal direction, and the two circuit substrates (10) are connected via a flexible circuit (19); the circuit substrate (10) on the lower side is attached to the bottom of the inner cavity of the base (4), the temperature probe (12) extends into a pre-buried cavity (17) below the inner cavity of the base (4), and the pre-buried cavity (17) is filled with epoxy glue.

7. A MEMS vibration and temperature composite sensor as claimed in claim 6, characterized in that: The connection end of the temperature probe (12) is connected to the circuit substrate (10) on the upper side, and the measuring end of the temperature probe (12) passes through the circuit substrate (10) on the lower side and extends into the embedded cavity (17); a clearance hole is provided on the circuit substrate (10) on the lower side to allow the temperature probe (12) to pass through.

8. A MEMS vibration and temperature composite sensor as claimed in claim 6, characterized in that: The circuit substrate (10) comprises a flexible circuit layer, a copper-clad shielding layer and a hard reinforcement layer which are arranged in sequence from top to bottom, and the hard reinforcement layer is made of an insulating material; the welding points of the vibration sensitive chip and the welding points of the temperature probe (12) are both located in the flexible circuit layer.

9. A MEMS vibration and temperature composite sensor as claimed in claim 6, characterized in that: The base (4) comprises: Base body; An extension portion (5), the extension portion (5) is connected to the bottom of the base body, the embedded cavity (17) is opened in the extension portion (5), the embedded cavity (17) is connected to the inner cavity of the base body, and the inner diameter of the embedded cavity (17) is smaller than the inner diameter of the inner cavity of the base body.

10. A MEMS vibration and temperature composite sensor as claimed in claim 9, characterized in that: The middle of the inner cavity of the base body has a limiting step with the end surface facing upward; the two circuit substrates (10) are respectively located at the bottom of the inner cavity of the base body and on the limiting step, and the output ends of the two circuit substrates (10) are located on the same side.

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