A new pressure sensor

Abstract

The utility model discloses a novel pressure sensor, including base, upper cover, PCBA board and MEMS chip. The base is closed with upper cover and forms the installation cavity, and its improved core lies in sealing connection structure: the base is equipped with the arc clamping slot of surrounding PCBA board, and the upper cover is equipped with the snap ring of clamping. The snap ring defines one continuous sealing glue containing channel with the arc clamping slot through its first cooperation arm, second cooperation arm and arc arm, and the channel is sequentially communicated with the second glue passing channel of gradually narrowing from top to bottom, the first glue passing channel at the bottom and the glue stagnation cavity for buffering and storing glue. The utility model discloses a three -dimensional flow passage through this preset, and the sealing glue is guided accurate filling and solidification, forms reliable three -dimensional covering type bonding, effectively prevents the colloid and penetrates inside and pollutes the element, and great enhancement upper cover and the firmness of base combination and sealing long -term reliability.

Description

Technical Field

[0001] This utility model relates to the field of MEMS pressure sensor technology, and in particular to a novel pressure sensor. Background Technology

[0002] The reliability of the connection between the pressure sensor's top cover and base directly determines its sealing performance and structural stability throughout its service life. Currently, the housing sealing of this type of sensor is often achieved by applying sealant to the mating surfaces or by injecting sealant after setting a simple snap-fit ​​structure.

[0003] However, this traditional method has inherent drawbacks: First, whether it's applying adhesive to a flat surface or filling the adhesive within a simple snap-fit ​​groove, the effective bonding area is usually limited to a single contact surface or a localized point or line area. This limited contact area at a single bonding interface makes it susceptible to stress concentration under vibration, temperature cycling, or internal stress changes, leading to fatigue cracking or detachment of the adhesive layer from the substrate surface, resulting in an unreliable bond. Second, to prevent adhesive seepage, precise control of the application amount is often required, which may leave weak points in the seal due to insufficient adhesive, preventing the formation of a complete and strong encapsulating bond.

[0004] Therefore, existing sealing connection methods struggle to create a robust mechanical interlocking structure with a large contact area and multi-directional meshing forces between housing components. There is an urgent need for an innovative connection solution that not only achieves the basic function of sealing but also guides the sealant to distribute and cure along a predetermined path in three-dimensional space, forming an adhesive layer that completely encapsulates the connection structure. This significantly enhances the bond strength and prevents seal failure due to loose connections. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a structure that solves the technical problem of unreliable connection of pressure sensors.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A novel pressure sensor includes a base, a top cover, a PCBA board, and a MEMS chip. The PCBA board is electrically connected to the MEMS chip. The top cover covers the base and forms a mounting cavity with the base. The PCBA board is disposed within the mounting cavity. The base has an air intake channel located directly below the MEMS chip. An arc-shaped slot is formed on the base, located on the outer side of the PCBA board. The top cover has a retaining ring that engages with the arc-shaped slot. The retaining ring includes an inclined section close to the MEMS chip. A first mating arm is provided on the outer wall of the arc-shaped groove, and a second adhesive passage gradually narrows from top to bottom between the first mating arm and the outer wall of the arc-shaped groove; the retaining ring includes an arc-shaped arm provided near the inner wall of the arc-shaped groove, and the arc-shaped arm cooperates with the arc-shaped groove to form a retaining cavity; the end of the first mating arm is provided with a second mating arm that is inclined towards the bottom wall of the arc-shaped groove; the second mating arm is connected to the arc-shaped arm to form a connecting arm, and the connecting arm is arranged parallel to the bottom wall of the arc-shaped groove and a first adhesive passage is formed between the two; the retaining cavity, the first adhesive passage, and the second adhesive passage are filled with sealant.

[0007] As a preferred embodiment of this utility model, the side of the top cover and / or the base is provided with an opening communicating with the mounting cavity, and the PCBA board at least partially protrudes and is exposed outside the opening to form an electrical connection portion, and the electrical connection portion is provided with a plurality of pads for soldering with leads.

[0008] As a preferred technical solution of this utility model, the base is integrally formed with a support platform and the support platform is provided with the arc-shaped slot along its contour direction, and the PCBA board and the MEMS chip are fixed to the outer surface of the support platform.

[0009] As a preferred embodiment of this utility model, the PCBA board is provided with a clearance hole, and the MEMS chip is disposed in the clearance hole.

[0010] In a preferred embodiment of this invention, the PCBA board and the MEMS chip are electrically connected via signal lines.

[0011] In a preferred embodiment of this invention, both the MEMS chip and the PCBA board are fixed to the surface of the support platform by bonding.

[0012] As a preferred embodiment of this utility model, the pads are provided in three places, which correspond to the power input terminal, the signal output terminal and the ground terminal respectively.

[0013] As a preferred embodiment of this utility model, the surface of the support platform is provided with an arc-shaped groove along its contour direction. The arc-shaped groove is located on the outer side of the PCBA board, and the upper cover is provided with a retaining ring that engages with the arc-shaped groove.

[0014] As a preferred embodiment of this utility model, the outer wall of the base at the end away from the top cover is provided with an annular groove, and an O-ring is fitted inside the annular groove.

[0015] As a preferred embodiment of the present invention, the air intake channel includes a first air intake hole and a second air intake hole arranged sequentially along the axial direction of the base. The first air intake hole is directly below the MEMS chip, and the second air intake hole is located at the end of the first air intake hole away from the MEMS chip. The diameter of the first air intake hole is smaller than the diameter of the second air intake hole.

[0016] In summary, the beneficial effects of this utility model are as follows: By setting up a continuous sealant flow channel system consisting of a "resistive adhesive cavity - first adhesive channel - second adhesive channel," the sealant can be uniformly and fully filled into the entire three-dimensional space between the retaining ring and the arc-shaped groove. After curing, the sealant does not only form contact with a single point or surface with the connecting structure, but forms a "three-dimensional encapsulation" adhesive layer that completely wraps around the outer side, bottom, and key parts of the retaining ring. This structure greatly increases the effective contact area between the sealant and the connecting components, making the top cover and the base firmly bonded together. It can effectively resist stress in all directions caused by vibration, impact, and temperature changes, fundamentally eliminating the risk of loosening.

[0017] By setting exposed electrical connections on the PCBA board and providing three pads corresponding to the power input, signal output, and ground terminals respectively, the traditional plug and pin structure is replaced, simplifying the lead connection. Simultaneously, the integrated support platform on the base eliminates the need for separate brackets and internal sealing rings. The PCBA board and MEMS chip are integrated and bonded to the support platform, and internal sealing is achieved by filling the gap between the top cover and the base with sealant. The assembly process eliminates complex steps such as riveting and FPC welding, increasing the continuity of the bonding process, improving production efficiency, and reducing process costs. Through high structural integration and simplification, the number of parts and product volume are significantly reduced, lowering material and process costs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an exploded view of this utility model; Figure 3 This is a cross-sectional view of the present invention; Figure 4 yes Figure 3 A magnified view of part A; Figure 5 This is a schematic diagram of the structure of the base and PCBA board in this utility model.

[0019] Reference numerals: 1. Base; 2. Top cover; 3. PCBA board; 4. MEMS chip; 5. Mounting cavity; 6. Air intake channel; 7. Opening; 8. Electrical connection part; 9. Solder pad; 10. Support platform; 11. Clearance hole; 12. Arc-shaped groove; 13. Snap ring; 14. Sealant; 15. Annular groove; 16. O-ring sealant; 17. First air intake; 18. Second air intake; 19. First mating arm; 20. Second adhesive passage; 21. Arc-shaped arm; 22. Adhesive retention cavity; 23. Second mating arm; 24. Connecting arm; 25. First adhesive passage. Detailed Implementation

[0020] To make the technical means, creative features, and achieved objectives and effects of this utility model easier to understand, the present utility model is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described in the implementation plan without creative effort are all within the protection scope of this utility model.

[0021] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0022] like Figures 1 to 5 The novel pressure sensor shown includes a base 1, a top cover 2, a PCBA board 3, and a MEMS chip 4. The PCBA board 3 is electrically connected to the MEMS chip 4. The top cover 2 covers the base 1 and forms a mounting cavity 5 between the top cover 2 and the base 1. The PCBA board 3 is disposed in the mounting cavity 5. The base 1 is provided with an air intake channel 6 located directly below the MEMS chip 4. The side of the top cover 2 and / or the base 1 is provided with an opening 7 communicating with the mounting cavity 5. The PCBA board 3 protrudes at least partially and is exposed outside the opening 7 to form an electrical connection portion 8. The electrical connection portion 8 is provided with a plurality of pads 9 for soldering to leads.

[0023] An arc-shaped slot 12 is provided on the base 1, located on the outer side of the PCBA board 3. A retaining ring 13 is provided on the upper cover 2 to engage with the arc-shaped slot 12. The retaining ring 13 includes a first mating arm 19 inclined towards the outer wall of the arc-shaped slot 12, forming a second adhesive passage 20 that gradually narrows from top to bottom between the first mating arm 19 and the outer wall of the arc-shaped slot 12. The retaining ring 13 also includes an arc-shaped arm 21 near the inner wall of the arc-shaped slot 12, which engages with the arc-shaped slot 12 to form a glue retention cavity 22. A second mating arm 23 inclined towards the bottom wall of the arc-shaped slot 12 is provided at the end of the first mating arm 19. The second mating arm 23 is connected to the arc-shaped arm 21 to form a connecting arm 24, which is parallel to the bottom wall of the arc-shaped slot 12 and forms a first adhesive passage 25 between them. The glue retention cavity 22, the first adhesive passage 25, and the second adhesive passage 20 are filled with sealant.

[0024] By setting up a continuous sealant flow channel system consisting of "adhesive retention cavity 22 - first adhesive passage 25 - second adhesive passage 20", the sealant can be uniformly and fully filled into the entire three-dimensional space between the retaining ring 13 and the arc-shaped groove 12. After curing, the sealant does not only form a single point or surface contact with the connecting structure, but forms a "three-dimensional encapsulation" adhesive layer that completely wraps the outer side, bottom, and key parts of the retaining ring 13. This structure greatly increases the effective contact area between the sealant and the connecting components, making the top cover 2 and the base 1 firmly bonded together. It can effectively resist stress in all directions caused by vibration, impact, and temperature changes, fundamentally eliminating the risk of loosening of the connection.

[0025] A support platform 10 is integrally formed on the surface of the base 1, and the PCBA board 3 and the MEMS chip 4 are fixed to the outer surface of the support platform 10. In this embodiment, there are three solder pads 9, corresponding to the power input terminal, signal output terminal, and ground terminal, respectively. In this embodiment, the upper cover 2 is a plastic part, which will not cause friction and rusting when assembled with the metal valve inside the car. It should be noted that the improvement of this application focuses on the physical packaging structure of the pressure sensor, aiming to solve the problems of size, cost, and reliability in the prior art through structural integration and simplification. For the core functions of the pressure sensor itself, such as the detection principle and signal processing circuit, this application adopts the technology known to those skilled in the art and does not make any fundamental changes. Therefore, the specification and drawings will focus on the description of the innovative mechanical structure, and the details of the known technologies will not be repeated.

[0026] By setting an exposed electrical connection part 8 on the PCBA board 3 and setting three pads 9 corresponding to the power input terminal, signal output terminal and ground terminal respectively, the traditional plug and pin structure is replaced, simplifying the lead connection. At the same time, the integrated support platform 10 on the base 1 eliminates the need for a separate bracket and internal sealing ring. The PCBA board 3 and MEMS chip 4 are integrated and bonded to the support platform 10, and the internal sealing is achieved by filling the gap between the upper cover 2 and the base 1 with sealant. This improves production efficiency and reduces process costs. Through high structural integration and simplification, the number of parts and product volume are significantly reduced, and material and process costs are lowered.

[0027] The PCBA board 3 has a clearance hole 11, and the MEMS chip 4 is disposed in the clearance hole 11. The PCBA board 3 and the MEMS chip 4 are electrically connected through a signal line. The signal line can be gold wire or alloy wire, etc. How to solder is not the focus of this application, so it is not described in detail here.

[0028] Both the MEMS chip 4 and the PCBA board 3 are fixed to the surface of the support platform 10 by bonding. The assembly process eliminates complex steps such as riveting and FPC welding, and increases the continuity of the bonding process.

[0029] The surface of the support platform 10 has an arc-shaped groove 12 along its contour direction. The arc-shaped groove 12 is located on the outer side of the PCBA board 3. The upper cover 2 has a retaining ring 13 that engages with the arc-shaped groove 12. The gap between the upper cover 2 and the base 1 is filled with sealant. In this embodiment, the purpose of the support platform 10 is to provide a support surface, replacing the traditional bracket structure.

[0030] This utility model employs a combination of snap-fit ​​and adhesive injection. Specifically, an arc-shaped groove 12 is machined along the contour of the support platform 10 and the outer side of the PCBA board 3; correspondingly, an inwardly protruding retaining ring 13 is designed on the inner wall of the upper cover 2. During assembly, the retaining ring 13 and the groove cooperate to achieve initial positioning and locking. On this basis, sealant is injected into the annular gap between the upper cover 2 and the base 1. After curing, this sealant forms a continuous and reliable airtight barrier, with a sealing effect superior to traditional O-ring or threaded sealing structures. It should be understood that the above-described snap-fit ​​method is only one of the preferred embodiments for connecting the upper cover 2 and the base 1, and not the only limitation of this utility model. Under the technical concept of this application, any connection method that can reliably fix the two falls within the scope of protection. For example, the upper cover 2 and the base 1 can also be assembled by threaded connection, ultrasonic welding, or fastener locking.

[0031] An annular groove 15 is provided on the outer wall of the end of the base 1 away from the upper cover 2, and an O-ring 16 is fitted inside the annular groove 15.

[0032] The air intake channel 6 includes a first air intake hole 17 and a second air intake hole 18 arranged sequentially along the axial direction of the base 1. The first air intake hole 17 faces directly below the MEMS chip 4, and the second air intake hole 18 is located at the end of the first air intake hole 17 away from the MEMS chip 4. The diameter of the first air intake hole 17 is smaller than the diameter of the second air intake hole 18. Optimizing the air intake channel 6 into two stages of channels with different diameters (the diameter of the first air intake hole 17 is smaller than that of the second air intake hole 18) allows pressure to be applied stably to the MEMS chip 4, improving the accuracy and stability of the measurement.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the utility model as defined by the appended claims and their equivalents.

Claims

1. A novel pressure sensor, comprising a base, a top cover, a PCBA board, and a MEMS chip, wherein the PCBA board is electrically connected to the MEMS chip, the top cover covers the base and forms a mounting cavity with the base, the PCBA board is disposed within the mounting cavity, and the base is provided with an air intake channel located directly below the MEMS chip, characterized in that: The base has an arc-shaped slot located on the outer side of the PCBA board. The top cover has a retaining ring that engages with the arc-shaped slot. The retaining ring includes a first mating arm inclined towards the outer wall of the arc-shaped slot, forming a second adhesive passage that gradually narrows from top to bottom between the first mating arm and the outer wall of the arc-shaped slot. The retaining ring also includes an arc-shaped arm near the inner wall of the arc-shaped slot, which engages with the arc-shaped slot to form a retaining cavity. The end of the first mating arm has a second mating arm inclined towards the bottom wall of the arc-shaped slot. The second mating arm connects with the arc-shaped arm to form a connecting arm, which is parallel to the bottom wall of the arc-shaped slot and forms a first adhesive passage between them. The retaining cavity, the first adhesive passage, and the second adhesive passage are filled with sealant.

2. The novel pressure sensor according to claim 1, characterized in that: The upper cover and / or the base have an opening on the side that communicates with the mounting cavity. The PCBA board protrudes at least partially and is exposed outside the opening to form an electrical connection portion. The electrical connection portion has a plurality of pads for soldering to leads.

3. The novel pressure sensor according to claim 2, characterized in that: The base is integrally formed with a support platform, and the support platform has an arc-shaped slot along its contour direction. The PCBA board and the MEMS chip are fixed to the outer surface of the support platform.

4. The novel pressure sensor according to claim 3, characterized in that: The PCBA board has clearance holes, and the MEMS chip is disposed in the clearance holes.

5. The novel pressure sensor according to claim 4, characterized in that: The PCBA board and the MEMS chip are electrically connected via signal lines.

6. The novel pressure sensor according to claim 3, 4, or 5, characterized in that: Both the MEMS chip and the PCBA board are fixed to the surface of the support platform by adhesive bonding.

7. The novel pressure sensor according to claim 2, characterized in that: The pads are provided in three places, corresponding to the power input terminal, signal output terminal and ground terminal respectively.

8. The novel pressure sensor according to claim 3, characterized in that: The surface of the support platform is provided with an arc-shaped groove along its contour direction. The arc-shaped groove is located on the outside of the PCBA board. The upper cover is provided with a retaining ring that engages with the arc-shaped groove.

9. The novel pressure sensor according to claim 1, characterized in that: The outer wall of the base away from the top cover has an annular groove, and an O-ring is fitted inside the annular groove.

10. The novel pressure sensor according to claim 1, characterized in that: The air intake channel includes a first air intake hole and a second air intake hole arranged sequentially along the axial direction of the base. The first air intake hole is directly below the MEMS chip, and the second air intake hole is located at the end of the first air intake hole away from the MEMS chip. The diameter of the first air intake hole is smaller than the diameter of the second air intake hole.

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