Silicon piezoresistive pressure sensor based on MEMS technology
By adopting LGA-4PIN metal shell and tube packaging technology in MEMS pressure sensors and adding anti-slip pads and metal contacts at the bottom of the circuit board, the MEMS pressure sensor has solved the problems of high power consumption, high cost, low performance and easy welding, and high precision, low power consumption, low cost and long-term stability.
Patent Information
- Application Number
- CN202421209734.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2034-05-30
AI Technical Summary
The existing MEMS pressure sensors have high power consumption, high cost, low performance, poor long-term stability, and are easy to slide during welding operations, resulting in welding errors.
The silicon piezoresistive pressure sensor based on MEMS technology is adopted, and the LGA-4PIN metal shell and tube packaging technology of the shell and the circuit board is packaged to increase ventilation holes for heat dissipation. Anti-slip pads and metal contacts are installed at the bottom of the circuit board to provide good thermal conductivity, heat dissipation and electrical conductivity, and provide stable support during welding.
It realizes the high accuracy, low power consumption, low cost, long-term stability and good welding performance of pressure sensors, reduces welding errors and extends service life.
Smart Images
Figure CN222652411U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of micro-electromechanical systems, in particular to a silicon piezoresistive pressure sensor based on MEMS technology. Background Art
[0002] Microelectromechanical systems (MEMS), also known as microelectronic mechanical systems, microsystems, micromachines, etc., refer to high-tech devices with a size of several millimeters or even smaller. The internal structure of a MEMS is generally in the micron or even nanometer range. It is an independent intelligent system. MEMS is developed on the basis of microelectronics technology (semiconductor manufacturing technology) and is a high-tech electronic mechanical device made by integrating technologies such as lithography, corrosion, thin film, LIGA, silicon micromachining, non-silicon micromachining and precision machining.
[0003] A MEMS pressure sensor is a thin film element that deforms when subjected to pressure. This deformation can be measured using a strain gauge (piezoresistive sensing) or by capacitive sensing of the change in distance between two surfaces. Common MEMS pressure sensors have high power consumption, high cost, low performance, and poor long-term stability, which can easily affect the accuracy of the pressure sensor. In addition, during welding operations, the pressure sensor is prone to slip, causing errors during welding. Utility Model Content
[0004] The purpose of the utility model is to provide a silicon piezoresistive pressure sensor based on MEMS technology to solve the problems of high power consumption, high cost, low performance, poor long-term stability, easy impact on the accuracy of the pressure sensor, and easy sliding of the pressure sensor during welding operations, resulting in errors during welding.
[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solution: a silicon piezoresistive pressure sensor based on MEMS technology, comprising a shell, a surface of the shell is provided with ventilation holes, a circuit board is fixedly connected to the bottom of the shell, a non-slip pad is fixedly connected to the surface of the circuit board, and a metal contact is fixedly connected to the surface of the circuit board.
[0006] Preferably, the shell is made of metal and is packaged using LGA-4PIN metal tube shell packaging technology.
[0007] Preferably, the circuit board uses absolute pressure when performing pressure sensing.
[0008] Preferably, the ventilation hole is cylindrical.
[0009] Preferably, the anti-slip pads are in the shape of long strips and are distributed at the four corners of the bottom surface of the circuit board.
[0010] Preferably, the metal contacts are in four groups and are mounted on the bottom of the circuit board.
[0011] Preferably, constant current excitation or constant voltage excitation is adopted when the metal contact is connected to a power source.
[0012] Compared with the prior art, the beneficial effects of the utility model are:
[0013] 1. The LGA-4PIN metal tube packaging technology is used to package the shell and circuit board, which provides protection for the internal chip of the pressure sensor. It has good thermal conductivity and heat dissipation, good electrical conductivity, reduces transmission delay and energy loss, is light in weight, and has sufficient strength and mechanical properties. It has good processing capabilities for mass production, low thermal expansion coefficient, so as to meet the matching with the chip, thereby reducing the generation of thermal stress, good welding performance, plating performance and corrosion resistance to achieve reliable combination with the chip, sealing and environmental protection, and can provide high-precision voltage output linearly related to the external sensing pressure. By opening ventilation holes on the surface of the shell, the heat dissipation capacity is further improved. Through the metal contacts set at the bottom of the circuit board, it is connected to the positive and negative poles of the power supply and outputs positive and negative voltages, providing users with a flexible way of use, allowing users to easily design and add subsequent signal processing circuits. It has the characteristics of small size, low power consumption, low cost, superior performance and good long-term stability.
[0014] 2. By setting the anti-skid pad at the bottom of the circuit board, the pressure sensor can better determine the position during welding. The anti-skid pad provides a certain friction during welding, which can provide stable support and prevent the friction noise when the object slides or moves to a certain extent, making the pressure sensor more stable and avoiding errors during welding. It can protect the surface from being scratched by objects, reduce wear and tear, and extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a front view stereoscopic schematic diagram of the structure of the utility model;
[0016] Figure 2 It is a schematic top view of the structure of the utility model;
[0017] Figure 3 It is a bottom view schematic diagram of the structure of the utility model;
[0018] Figure 4 It is a schematic side view of the structure of the utility model;
[0019] Figure 5 It is a schematic structural stereoscopic diagram of a circuit board and an anti-skid pad of the utility model.
[0020] In the figure: 1. Shell; 2. Circuit board; 3. Ventilation holes; 4. Anti-slip pad; 5. Metal contacts. DETAILED DESCRIPTION
[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0022] See also Figure 1-5 , an embodiment provided by the utility model:
[0023] A silicon piezoresistive pressure sensor based on MEMS technology comprises a shell 1, a ventilation hole 3 is opened on the surface of the shell 1, a circuit board 2 is fixedly connected to the bottom of the shell 1, an anti-skid pad 4 is fixedly connected to the surface of the circuit board 2, and a metal contact 5 is fixedly connected to the surface of the circuit board 2. The shell 1 and the circuit board 2 are packaged by adopting LGA-4PIN metal tube shell packaging technology. The metal contact 5 arranged at the bottom of the circuit board 2 provides protection for the internal chip of the pressure sensor, and can provide a high-precision voltage output linearly related to the external sensed pressure, so that the user can conveniently design and add subsequent signal processing circuits. The anti-skid pad 4 is arranged at the bottom of the circuit board 2, and the anti-skid pad 4 provides a certain friction during welding, so that the pressure sensor is not easy to slide, thereby avoiding errors during welding.
[0024] Furthermore, the housing 1 is made of metal and is packaged using LGA-4PIN metal tube shell packaging technology. It has good thermal conductivity and heat dissipation, good electrical conductivity, reduces transmission delay and energy loss, is light in weight, and has sufficient strength and mechanical properties. It has good processing capabilities to facilitate mass production, a low thermal expansion coefficient to meet the matching requirements with the chip, thereby reducing the generation of thermal stress, good welding performance, plating performance and corrosion resistance to achieve reliable bonding with the chip, sealing and environmental protection, and provides protection for the chip inside the pressure sensor.
[0025] Furthermore, the circuit board 2 uses absolute pressure when performing pressure sensing, which can accurately measure pressure changes and feed the data back to the control system for corresponding adjustment and control to ensure stability and safety.
[0026] Furthermore, the ventilation hole 3 is cylindrical, which ensures smooth airflow and further improves the heat dissipation capacity.
[0027] Furthermore, the anti-skid pad 4 is in the shape of a long strip and is distributed at the four corners of the bottom surface of the circuit board 2, so that the pressure sensor can better determine the position during welding. The anti-skid pad provides a certain friction during welding, can provide a stable support, and to a certain extent prevent the friction noise when the object slides or moves, making the pressure sensor more stable, avoiding errors during welding, and protecting the surface from being scratched by objects, reducing wear and tear, and extending the service life.
[0028] Furthermore, the metal contacts 5 are in four groups, mounted on the bottom of the circuit board 2, connected to the positive and negative electrodes of the power supply to provide the required power supply voltage and serve as a grounding, and can also be used to supply the power supply voltage required by other circuits or components.
[0029] Furthermore, when the metal contact 5 is connected to a power source, constant current excitation or constant voltage excitation is adopted. Both excitation modes can be used, with high compatibility and convenient use.
[0030] Working principle: The shell 1 of the pressure sensor is packaged with LGA-4PIN metal tube packaging technology, which has good thermal conductivity and heat dissipation, good electrical conductivity, reduces transmission delay and energy loss, is light in weight, and has sufficient strength and mechanical properties, good processing capabilities for mass production, low thermal expansion coefficient, so as to meet the matching with the chip, thereby reducing the generation of thermal stress, good welding performance, plating performance and corrosion resistance to achieve reliable combination with the chip, sealing and environmental protection, and provide protection for the chip inside the pressure sensor. The principle of pressure detection is that when there is no external pressure, the Wheatstone bridge is in equilibrium, and the output voltage of the sensor chip is zero. When the external pressure causes the detection film to deform, the sensor chip It outputs a non-zero voltage, and the size of the external pressure can be obtained according to the non-zero voltage, thereby realizing pressure detection. When installing the pressure sensor, align the metal contact 5 on the pad, connect it to the positive and negative poles of the power supply to provide the required power supply voltage and play a grounding role. It can also be used to supply the power supply voltage required by other circuits or components. The anti-slip pad 4 provides a certain friction during welding, so that the pressure sensor is not easy to slide, avoiding errors during welding. When using an electric soldering iron to solder the pressure sensor, use an electric soldering iron with a temperature of 260 to 300 degrees to complete the operation within five seconds. After soldering on the pin, it should be left for a period of time before use to avoid damage to components. When using reflow soldering, use 230 degrees to complete the operation within ten seconds.
[0031] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.
Claims
1. A silicon piezoresistive pressure sensor based on MEMS technology, comprising a housing (1), characterized in that: A ventilation hole (3) is provided on the surface of the shell (1), a circuit board (2) is fixedly connected to the bottom of the shell (1), an anti-slip pad (4) is fixedly connected to the surface of the circuit board (2), and a metal contact (5) is fixedly connected to the surface of the circuit board (2).
2. The silicon piezoresistive pressure sensor based on MEMS technology according to claim 1, characterized in that: The housing (1) is made of metal and is packaged using LGA-4PIN metal tube shell packaging technology.
3. The silicon piezoresistive pressure sensor based on MEMS technology according to claim 1, characterized in that: The circuit board (2) uses absolute pressure when performing pressure sensing.
4. The silicon piezoresistive pressure sensor based on MEMS technology according to claim 1, characterized in that: The ventilation hole (3) is cylindrical.
5. The silicon piezoresistive pressure sensor based on MEMS technology according to claim 1, characterized in that: The anti-slip pads (4) are in the shape of long strips and are distributed at the four corners of the bottom surface of the circuit board (2).
6. The silicon piezoresistive pressure sensor based on MEMS technology according to claim 1, characterized in that: The metal contacts (5) are in four groups and are mounted on the bottom of the circuit board (2).
7. The silicon piezoresistive pressure sensor based on MEMS technology according to claim 1, characterized in that: When the metal contact (5) is connected to a power source, constant current excitation or constant voltage excitation is adopted.