Air pressure sensor packaging device and method

Abstract

The invention belongs to the technical field of monitors, and particularly relates to an air pressure sensor packaging device and method. According to the technical scheme, the air pressure sensor packaging device comprises an outer body, a mounting cavity and a buffer cavity which are communicated with each other are formed in the outer body, a shrinkage cavity used for communicating the buffer cavity with the outside is formed in the outer body, a thickened PCB is mounted in the mounting cavity, one side, facing the buffer cavity, of the thickened PCB is connected with a ceramic chip, chip particles are mounted on the ceramic chip, and the chip particles are embedded in the mounting cavity. A stainless steel ring is fixed on the ceramic chip, jelly-shaped glue is arranged in the stainless steel ring, the chip particles are located in the jelly-shaped glue, and a bonding wire pin is connected to one side, far away from the buffer cavity, of the thickened PCB. The invention provides an air pressure sensor packaging device and method. The air pressure sensor packaging device and method ensure that a sensor stably and accurately measures atmospheric pressure under the long-term weather-proof condition.

Description

Technical Field

[0001] This invention belongs to the field of monitoring instrument technology, and specifically relates to a barometric pressure sensor packaging device and method. Background Technology

[0002] The wireless ECP system is applied to heavy-haul railway trains. A monitoring unit is installed in the first car, and each freight car is equipped with an onboard control device. The monitoring unit obtains train formation information from ground services, activates the onboard control devices in the train to establish and manage the train's wireless ad hoc network, and also monitors atmospheric pressure and sends it to each onboard control device to convert absolute pressure readings into gauge pressure readings for train operation and control. The wireless ECP system consists of the following components: Figure 3 As shown.

[0003] The monitoring device is installed on a heavy-duty vehicle in a complex and harsh environment. Therefore, a button-type digital barometric pressure sensor was selected, featuring high accuracy, built-in temperature compensation, good linearity and stability, low drift, and low power consumption. The sensor is a delicate electronic device with high sensitivity, requiring a suitable installation structure and application method. Existing sensor packaging structures cannot guarantee stable and accurate atmospheric pressure measurement under long-term weathering conditions. Summary of the Invention

[0004] In order to solve the above-mentioned problems in the prior art, the purpose of this invention is to provide a barometric pressure sensor packaging device and method to ensure that the sensor can stably and accurately measure atmospheric pressure under long-term weathering conditions.

[0005] The technical solution adopted in this invention is as follows: A barometric pressure sensor packaging device includes an outer body, within which a mounting cavity and a buffer cavity are connected. The outer body has a shrinkage hole for connecting the buffer cavity to the outside. A thickened PCB board is mounted in the mounting cavity. A ceramic plate is connected to the side of the thickened PCB board facing the buffer cavity. A chip is mounted on the ceramic plate. A stainless steel ring is fixed on the ceramic plate. A jelly-like adhesive is disposed inside the stainless steel ring. The chip is located inside the jelly-like adhesive. Solder pins are connected to the side of the thickened PCB board away from the buffer cavity.

[0006] This invention utilizes weather-resistant materials to create a specially structured outer body, which is machined with internal and external steps, a buffer cavity, a constriction cavity, external threads, a sealing ring groove, a bowl-shaped groove, and a water guide channel. The buffer cavity and constriction cavity structure can reduce the impact of ambient air disturbance on the accuracy of air pressure testing. The external threads ensure a secure installation on the monitoring instrument housing, and the sealing ring inserted into the sealing ring groove ensures the waterproof seal of the monitoring instrument housing. The bowl-shaped groove and water guide channel can minimize the adhesion and entry of rain, snow, dust, and other contaminants around the constriction cavity.

[0007] This invention manufactures a thickened PCB board. One side of the thickened PCB board can be used to solder and fix the pressure sensor, and the other side can be used to solder and fix the lead wires. The thickened PCB board increases the resistance to bending deformation and has good planarity retention. After the sensor is soldered, it provides stable and strong support for the sensor ceramic chip, which can reduce the stress transmitted to the ceramic chip due to micro-deformation and thus reduce the impact on chip testing.

[0008] The pressure sensor of this invention is first welded and fixed to a thickened PCB board. Before being placed into the outer casing, silicone rubber is applied around the pressure sensor. After the pressure sensor is placed in position, the silicone rubber is automatically compressed and fills the area around the pressure sensor. After curing, it provides sealing, support, and vibration and impact buffering for the pressure sensor. The adhesive has low shrinkage stress after curing, which has little impact on the test. The space between the back of the thickened PCB board and the outer casing wall is filled with potting compound. The potting compound has strong adhesion and, after natural curing upon contact with air, has a certain strength and flexibility, providing sufficient support to the PCB board to prevent the sensor from shifting.

[0009] When the monitoring device is mounted on a heavy-duty vehicle, the barometric pressure sensor protrudes vertically downwards from the housing. This prevents the wind direction from directly impacting the external orifice and creating additional pressure within the buffer chamber, which could affect test accuracy. It also allows rain, snow, and dust entering the orifice to fall off automatically by their own weight, preventing them from accumulating in the orifice and buffer chamber and affecting the normal transmission of atmospheric pressure to the chip particles.

[0010] As a preferred embodiment of the present invention, the space between the mounting cavity and the solder pin is filled with potting compound, and the end of the solder pin away from the thickened PCB extends out of the potting compound.

[0011] As a preferred embodiment of the present invention, the ceramic piece and the stainless steel ring are respectively filled with silicone sealant between themselves and the inner cavity of the outer body.

[0012] As a preferred embodiment of the present invention, the outer end of the outer body is provided with a bowl-shaped groove, and the shrinkage hole communicates with the bowl-shaped groove.

[0013] As a preferred embodiment of the present invention, the bowl-shaped groove is provided with a plurality of water guide grooves in the radial direction.

[0014] As a preferred embodiment of the present invention, the outer body includes a mounting end and a protruding end. The protruding end protrudes from an opening on the chassis of the monitor. The mounting end is pressed against the inner wall of the chassis of the monitor. A hexagonal nut is threaded onto the protruding end. The hexagonal nut is pressed against the outer wall of the chassis of the monitor by a washer.

[0015] As a preferred embodiment of the present invention, a rubber ring is provided on the side of the mounting end facing the inner wall of the monitor's chassis.

[0016] As a preferred embodiment of the present invention, the monitoring device is installed on a heavy-duty vehicle, and the installation direction of the encapsulation device is vertically downward on the outside of the constriction hole.

[0017] In a preferred embodiment of the present invention, the number of chip particles is two.

[0018] A method for packaging a barometric pressure sensor includes the following steps: S1: The outer body is made of weather-resistant material with a special structure, and the outer end face of the outer body is machined with a bowl-shaped groove and a water guide groove; S2: The pressure sensor is welded and fixed on the thickened PCB board, and the wiring pins are welded and fixed on the back of the thickened PCB board; the pressure sensor is composed of ceramic plate, chip, stainless steel ring and jelly-like adhesive. S3: Place an outer casing around the barometric pressure sensor for fixation; S4: Fill the space between the back of the thickened PCB board and the outer wall with potting compound, exposing the solder pins; S5: Pass the encapsulated barometric pressure sensor through the opening in the chassis of the monitor; S6: Mount the monitoring device onto the heavy-duty vehicle, ensuring the air pressure sensor protrudes vertically downwards from the housing.

[0019] The beneficial effects of this invention are as follows: 1. This invention uses weather-resistant material to create a specially structured outer body, which is machined with inner and outer steps, a buffer cavity, a contraction cavity, external threads, a sealing ring groove, a bowl-shaped groove, and a water guide channel. The buffer cavity and contraction cavity structure can reduce the impact of ambient air disturbance on the accuracy of air pressure testing. The external threads ensure a secure installation on the monitoring instrument housing, and the sealing ring inserted into the sealing ring groove ensures the waterproof seal of the monitoring instrument housing. The bowl-shaped groove and water guide channel can minimize the adhesion and entry of rain, snow, dust, and other substances around the contraction cavity.

[0020] 2. This invention manufactures a thickened PCB board. One side of the thickened PCB board can be used to solder and fix the pressure sensor, and the other side can be used to solder and fix the lead wires. The thickened PCB board increases its resistance to bending deformation and has good planarity retention. After the sensor is soldered, it provides stable and strong support for the sensor ceramic chip, which can reduce the stress transmitted to the ceramic chip due to micro-deformation, thus reducing the impact on chip testing.

[0021] 3. The pressure sensor of this invention is first welded and fixed to a thickened PCB board. Before being placed into the outer casing, silicone rubber is applied around the pressure sensor. After the pressure sensor is placed in position, the silicone rubber is automatically compressed and fills the area around the pressure sensor. After curing, it provides sealing, support, and vibration and impact buffering for the pressure sensor. The cured adhesive has low shrinkage stress, which has little impact on the test. The space between the back of the thickened PCB board and the outer casing wall is filled with potting compound. The potting compound has strong adhesion and, after natural curing in air, has a certain strength and flexibility, providing sufficient support to the PCB board to prevent sensor movement.

[0022] 4. When the monitoring device is fixed on a heavy-duty vehicle, the part of the air pressure sensor protruding from the housing is vertically downward. This avoids the wind direction being directly opposite the constriction hole of the outer body, which would create additional pressure in the buffer cavity and affect the accuracy of the test. It also allows rain, snow, sand and dust that enter the constriction hole to fall off automatically by their own weight, avoiding the deposition in the constriction hole and buffer cavity, which would affect the normal transmission of atmospheric pressure to the chip particles. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the present invention; Figure 2 This is the right view of the present invention; Figure 3 This is a schematic diagram of the train's wireless ECP system configuration.

[0024] In the diagram: 1-Outer body; 2-Thickened PCB board; 3-Pressure sensor; 4-Hexagonal nut; 11-Mounting cavity; 12-Buffer cavity; 13-Shrinkage cavity; 14-Bowl-shaped groove; 15-Water guide groove; 16-Mounting end; 17-Extended end; 18-Rubber ring; 21-Soldering lead; 22-Potent; 31-Ceramic chip; 32-Chip particle; 33-Stainless steel ring; 34-Jelly adhesive; 35-Organic silicone sealant; 41-Gasket. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0027] like Figure 1 and Figure 2As shown, the barometric pressure sensor packaging device includes an outer body 1, inside which are a mounting cavity 11 and a buffer cavity 12. The outer body 1 has a shrinkage hole 13 for connecting the buffer cavity 12 with the outside. A thickened PCB board 2 is installed in the mounting cavity 11. A ceramic plate 31 is connected to the side of the thickened PCB board 2 facing the buffer cavity 12. Two chip particles 32 are installed on the ceramic plate 31. A stainless steel ring 33 is fixed on the ceramic plate 31. A jelly-like adhesive 34 is disposed inside the stainless steel ring 33. The chip particles 32 are located inside the jelly-like adhesive 34. A soldering pin 21 is connected to the side of the thickened PCB board 2 away from the buffer cavity 12.

[0028] The mounting cavity 11 and the solder pin 21 are filled with potting compound 22, with the end of the solder pin 21 away from the thickened PCB extending beyond the potting compound 22. The ceramic plate 31 and the stainless steel ring 33 are respectively filled with silicone sealant 35 between themselves and the inner cavity of the outer body 1. A bowl-shaped groove 14 is provided at the outer end of the outer body 1, and the shrinkage hole 13 communicates with the bowl-shaped groove 14. Several water-guiding grooves 15 are radially arranged in the bowl-shaped groove 14.

[0029] The outer body 1 includes a mounting end 16 and a protruding end 17. The protruding end 17 extends through an opening in the chassis of the monitor. The mounting end 16 is pressed against the inner wall of the monitor chassis. A hexagonal nut 4 is threaded onto the protruding end 17, and the hexagonal nut 4 is pressed against the outer wall of the monitor chassis by a washer 41. A rubber ring 18 is provided on the side of the mounting end 16 facing the inner wall of the monitor chassis. The monitor is installed on a heavy-duty vehicle, and the mounting direction of the encapsulation device is vertically downward from the outside of the constriction hole 13.

[0030] The packaging method for the barometric pressure sensor includes the following steps: S1: The outer body 1 is made of weather-resistant material with a special structure. The outer body 1 has a buffer cavity 12, a shrinkage cavity 13, and a step for internal installation of sensors and thickened PCB board 2. The outer body also has steps and threads. There is also an annular groove for placing a sealing ring at the root of the outer steps. The right end face of the outer body 1 is machined with a bowl-shaped groove 14 and a water guide groove 15. S2: The pressure sensor 3 is welded and fixed on the thickened PCB board 2, and the wiring pins are welded and fixed on the back of the thickened PCB board 2; wherein, the ceramic plate 31, the chip 32, the stainless steel ring 33 and the jelly-like adhesive 34 constitute the pressure sensor 3. S3: After applying silicone rubber around the pressure sensor 3, it is placed inside the outer body 1 and fixed; the silicone sealant 35 will cure naturally upon contact with air, and after curing, it has a certain strength and flexibility; S4: Fill the space between the back of the thickened PCB board 2 and the outer wall of the body 1 with potting compound 22, exposing the solder pins 21; the potting compound 22 also has a certain strength and flexibility after it is exposed to air and naturally cured. S5: Pass the encapsulated air pressure sensor 3 through the opening on the chassis from inside the monitor, insert the protruding part into the gasket 41 and tighten it with the hexagonal nut 4. S6: Fix the monitoring device to the heavy-duty vehicle so that the air pressure sensor 3 protrudes vertically downwards from the casing.

[0031] This invention uses weather-resistant material to create a specially structured outer body 1, which is machined with inner and outer steps, a buffer cavity 12, a constriction cavity 13, external threads, a sealing ring groove, a bowl-shaped groove 14, and a water guide groove 15. The buffer cavity 12 and the constriction cavity 13 structure can reduce the impact of ambient air disturbance on the accuracy of air pressure testing. The threads on the outer body 1 ensure a secure installation on the monitoring instrument housing, and the sealing ring inserted into the sealing ring groove ensures the waterproof seal of the monitoring instrument housing. The bowl-shaped groove 14 and the water guide groove 15 can minimize the adhesion and entry of rain, snow, sand, and other substances around the constriction cavity 13 into the constriction cavity 13.

[0032] This invention manufactures a thickened PCB board 2. One side of the thickened PCB board can be used to weld and fix the air pressure sensor 3, and the other side can be used to weld and fix the solder pads 21. The thickened PCB board 2 increases the resistance to bending and deformation, and has good planarity retention. After the sensor is welded, it provides stable and strong support for the sensor ceramic plate 31, which can reduce the stress transmitted to the ceramic plate 31 by micro-deformation, thus reducing the impact on the testing of the chip 32.

[0033] In this invention, the pressure sensor 3 is first welded and fixed onto the thickened PCB board 2. Before being placed into the outer body 1, silicone rubber is applied around the pressure sensor 3. After the pressure sensor 3 is placed in place, the silicone rubber is automatically squeezed and fills the area around the pressure sensor 3. After curing, it provides sealing, support, and cushioning against vibration and impact for the pressure sensor 3. The adhesive has low shrinkage stress after curing, which has little impact on the test. The space between the back of the thickened PCB board 2 and the wall of the outer body 1 is filled with potting compound 22. The potting compound 22 has strong adhesion and, after natural curing in contact with air, has a certain strength and flexibility, providing sufficient support to the PCB board to prevent the sensor from shifting.

[0034] When the monitoring device is fixed on a heavy-duty vehicle, the barometric pressure sensor 3 protrudes vertically downwards from the housing to prevent the wind direction from directly facing the constriction hole 13 of the outer body 1, which would create additional pressure in the buffer cavity 12 and affect the accuracy of the test. It also allows rain, snow, sand and dust that enter the constriction hole 13 to fall off automatically by their own weight, preventing them from depositing in the constriction hole 13 and the buffer cavity 12 and affecting the normal transmission of atmospheric pressure to the chip particles 32.

[0035] Example: Barometric pressure sensor 3 is a general-purpose device, and its structure is as follows: Figure 1 and 2As shown, a tiny chip 32, about the size of a sesame seed, for measuring air pressure and performing analog-to-digital conversion, is soldered and fixed onto a 6.5mm x 6.5mm square ceramic plate 31. Solder feet are also made on the back of the ceramic plate 31. A stainless steel ring 33 is bonded around the chip 32 on the ceramic plate 31, and a jelly-like adhesive 34 is filled inside the stainless steel ring 33. The stainless steel ring 33 and the jelly-like adhesive 34 are used to introduce and transmit air pressure to the chip 32, which senses the air pressure, and also provide partial protection for the two chip 32s and the connecting wires. However, sharp or hard objects penetrating the jelly-like adhesive 34 may still damage the air pressure sensor 3.

[0036] This packaging structure solders the pressure sensor 3 onto the thickened PCB board 2, inserts it into a specially designed weather-resistant outer body 1, and then seals the surrounding area with potting compound 22 and silicone sealant 35. This provides support and cushioning for the pressure sensor 3, as well as sealing and protecting the soldering pins 21. Atmospheric pressure is introduced into the outer body 1 through the shrinkage hole 13 at the right end, and then passes through the buffer chamber 12 before acting on the sensitive device.

[0037] After encapsulation, the barometric pressure sensor 3 passes through an opening inside the chassis and is clamped to the chassis wall using a washer 41 and a hexagonal nut 4. Once fixed to the monitor and installed on the vehicle, it is vertically downwards. This minimizes the interference of wind direction directly hitting the constriction orifice 13 with atmospheric pressure measurement and reduces the entry of sand, dust, and snow into the buffer chamber 12. The bowl-shaped groove 14 and water guide 15 on the right side of the outer body 1 further reduce the adhesion of water and other objects to the constriction orifice 13, preventing blockage. The encapsulated barometric pressure sensor 3 is fixed through the chassis wall, and a groove is machined at the root of the thread close to the inner wall of the chassis to install a rubber ring 18, preventing external rainwater from entering the chassis.

[0038] The back of the thickened PCB board 2 is welded with solder pins 21, and after the sensor is packaged, the circuit can be soldered out from the solder pins 21.

[0039] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A pressure sensor packaging device, characterized in that: The device includes an outer body (1), which has a connected mounting cavity (11) and a buffer cavity (12). The outer body (1) has a shrinkage hole (13) for connecting the buffer cavity (12) with the outside. A thickened PCB board (2) is installed in the mounting cavity (11). A ceramic plate (31) is connected to the side of the thickened PCB board (2) facing the buffer cavity (12). A chip particle (32) is installed on the ceramic plate (31). A stainless steel ring (33) is fixed on the ceramic plate (31). A jelly-like glue (34) is provided inside the stainless steel ring (33). The chip particle (32) is located inside the jelly-like glue (34). A soldering pin (21) is connected to the side of the thickened PCB board (2) away from the buffer cavity (12).

2. The pressure sensor packaging device according to claim 1, characterized in that: The mounting cavity (11) and the soldering pin (21) are filled with potting compound (22), and the soldering pin (21) extends out of the potting compound (22) at the end away from the thickened PCB.

3. The barometric pressure sensor packaging device according to claim 1, characterized in that: The ceramic piece (31) and the stainless steel ring (33) are respectively filled with silicone sealant (35) between them and the inner cavity of the outer body (1).

4. The pressure sensor packaging device according to claim 1, characterized in that: The outer end of the outer body (1) is provided with a bowl-shaped groove (14), and the shrinkage hole (13) is connected to the bowl-shaped groove (14).

5. A pressure sensor packaging device according to claim 4, characterized in that: The bowl-shaped groove (14) is radially provided with several water guide grooves (15).

6. The barometric pressure sensor packaging device according to claim 1, characterized in that: The outer body (1) includes a mounting end (16) and an extension end (17). The extension end (17) protrudes from the opening on the chassis of the monitor. The mounting end (16) is pressed against the inner wall of the chassis of the monitor. A hexagonal nut (4) is threaded onto the extension end (17). The hexagonal nut (4) is pressed against the outer wall of the chassis of the monitor by a washer (41).

7. A pressure sensor packaging device according to claim 6, characterized in that: A rubber ring (18) is provided on the side of the mounting end (16) facing the inner wall of the monitor's chassis.

8. A pressure sensor packaging device according to claim 6, characterized in that: The monitoring device is installed on the heavy-duty vehicle, and the installation direction of the encapsulation device is vertically downward on the outside of the shrinkage hole (13).

9. A pressure sensor packaging device according to claim 1, characterized in that: The number of chip particles (32) is two.

10. A method for packaging a pressure sensor (3), using a pressure sensor packaging device according to any one of claims 1 to 9, characterized in that: Includes the following steps: S1: The outer body (1) with a special structure is made of weather-resistant material. The outer end face of the outer body (1) is machined with a bowl-shaped groove (14) and a water guide groove (15). S2: The pressure sensor (3) is welded and fixed on the thickened PCB board (2), and the wiring pins are welded and fixed on the back of the thickened PCB board (2); wherein, the ceramic plate (31), the chip particle (32), the stainless steel ring (33) and the jelly-like glue (34) constitute the pressure sensor (3); S3: Place the outer body (1) around the pressure sensor (3) and fix it inside; S4: Fill the space between the back of the thickened PCB board (2) and the outer wall (1) with potting compound (22) to expose the soldering pins (21). S5: Pass the outer body (1) of the encapsulated air pressure sensor (3) through the opening on the chassis inside the monitor; S6: Fix the monitoring device to the heavy-duty vehicle so that the air pressure sensor (3) protrudes vertically downward from the box.

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