A car intake pressure sensor

Abstract

This application provides an automotive intake pressure sensor, which uses a barrel-shaped chip mounting base with one open end and one closed end. The sensor chip is placed inside the chip mounting base, and the printed circuit board is placed outside the chip mounting base. The chip mounting base seals the gas medium inlet, directing the incoming gas medium directly to the sensor chip at the bottom of the barrel. The printed circuit board is not exposed to the gas medium and will not be contaminated or damaged by the gas medium. When high-speed medium rushes into the barrel-shaped mounting base, it presses the sensor chip firmly against the bottom of the barrel. This effectively seals the pins at the bottom of the barrel with through holes, eliminating the need for additional sealing structures such as sealant. This not only reduces processing steps but also avoids the disadvantages of using adhesives, effectively improving the sensor's service life.

Description

Technical Field

[0001] This utility model relates to the field of pressure sensor technology, specifically to an automotive intake pressure sensor. Background Technology

[0002] Silicon piezoresistive pressure sensors are made using the piezoresistive effect of single-crystal silicon. Four equal-value semiconductor resistors are diffused in a specific direction on a silicon diaphragm and connected to form a Wheatstone bridge, serving as the sensitive element of a force-to-electrical converter. When the diaphragm is subjected to external pressure, the bridge becomes unbalanced. If an excitation power supply (constant current and constant voltage) is applied to the bridge, an output voltage proportional to the measured pressure can be obtained, thus achieving the purpose of pressure measurement. Currently, the main application mode of silicon piezoresistive pressure sensors is to encapsulate the sensor within a base assembly consisting of a plastic base and a metal lead frame, forming a pressure measuring device. The portion of the lead frame protruding from the base serves as the circuit pins for communication between the pressure measuring device and external circuitry. For example, patent document CN214373097U discloses an automotive intake pressure sensor based on a silicon piezoresistive pressure sensor. In this solution, the pressure-measuring sensor chip is set on one side of the printed circuit board, directly facing the medium from the intake channel. The sensor chip is embedded in the printed circuit board, and the base and the fixing cover are sealed with sealant. A sealing ring is installed between the fixing cover and the chip.

[0003] However, this sensor structure is relatively complex and requires high assembly precision. If put into actual production, the processing steps would be numerous, and the yield rate would be relatively low. Furthermore, because the sensor chip is embedded on a printed circuit board and both are placed within the cavity of the fixed cover, in real-world use, the sensor detects the absolute pressure within the intake manifold. When high-speed media enters, the pressure-sensing surface of the sensor chip is subjected to stress, exposing a portion of the printed circuit board to the medium. This can damage the circuit board over time, affecting its lifespan. Moreover, because sealant is used in the structure, a dispensing process is required to form the sealing ring. Issues such as uneven dispensing, excessive or insufficient dispensing due to the adhesive's properties or the dispensing method can lead to poor sealing or contamination of other components. Regardless of the type of adhesive, curing takes time, resulting in excessively long production cycles and increased time costs. During product use, especially in harsh environments, the adhesive itself can change shape, eventually failing and affecting the product's lifespan. Utility Model Content

[0004] To address the issue that the structure of existing sensors can affect their lifespan, this invention provides an automotive intake pressure sensor that can effectively improve the sensor's lifespan while also having a simple structure that is easy to manufacture.

[0005] The structure of this utility model is as follows: an automotive intake pressure sensor, comprising: a housing, an air nozzle, a printed circuit board and a sensor chip, characterized in that it further comprises: a chip mounting base, wherein the chip mounting base is a barrel-shaped structure with one end open and the other end bottomed, and a through hole for pins is provided at the bottom of the barrel.

[0006] An installation cavity is provided inside the outer shell, and a gas medium inlet is provided at the bottom of the installation cavity;

[0007] The printed circuit board and the chip mounting base are arranged adjacent to each other in the mounting cavity; the open end of the chip mounting base is fixedly connected to the inner wall of the housing and communicates with the gas medium inlet;

[0008] The sensor chip is disposed on the bottom of the chip mounting base, and the chip pins are disposed on the back side of the pressure sensing surface of the sensor chip; the chip pins pass through the bottom of the chip mounting base through the pins via through holes and are electrically connected to the printed circuit board; the pressure sensing surface of the sensor chip faces the gas medium inlet.

[0009] The air nozzle is disposed on the housing, and the gas channel inside the air nozzle is connected to the opening end of the chip mounting base via the gas medium inlet.

[0010] Its further features are:

[0011] The diameter of the opening end of the chip mounting base is larger than the diameter of the gas medium inlet, and the two are concentrically arranged.

[0012] The bottom of the chip mounting base is provided with columnar feet, and the circuit board is provided with positioning through holes. The columnar feet pass through the positioning through holes and are fixedly connected to the circuit board.

[0013] The opening end of the chip mounting base is configured as an annular convex structure;

[0014] The mounting cavity is a stepped cavity, comprising: a first cavity, a second cavity, and a third cavity whose dimensions gradually increase from the inside out and are interconnected; the chip mounting base is disposed in the first cavity, and the printed circuit board is disposed in the second cavity;

[0015] It also includes a cover plate disposed in the third cavity;

[0016] It also includes: an external interface and external interface terminals, wherein the external interface is disposed on the housing and is interconnected with the mounting cavity via a terminal guide channel; the external interface terminals are disposed in the external interface and are connected to the printed circuit board via the terminal guide channel;

[0017] The outer shell, the external interface, and the air nozzle are integrally formed.

[0018] This application provides an automotive intake pressure sensor, which uses a barrel-shaped chip mounting base with one open end and one closed end. The sensor chip is placed inside the chip mounting base, and the printed circuit board is placed outside the chip mounting base. The chip mounting base seals the gas medium inlet, directing the incoming gas medium directly to the sensor chip at the bottom of the barrel. The printed circuit board is not exposed to the gas medium and will not be contaminated or damaged by the gas medium. When high-speed medium rushes into the barrel-shaped mounting base, it presses the sensor chip firmly against the bottom of the barrel, effectively sealing the pins at the bottom of the barrel with through holes. There is no need for additional sealing structures such as sealant. Compared with the prior art, this not only reduces the number of processing steps but also avoids the disadvantages of using glue, effectively improving the service life of the sensor. Moreover, the barrel-shaped chip mounting base has a simple structure, is easy to process, and does not increase the product processing cost. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the automotive intake pressure sensor of this application;

[0020] Figure 2 This is an exploded structural diagram of the automotive intake pressure sensor of this application;

[0021] Figure 3 This is a schematic diagram of the outer shell structure;

[0022] Figure 4 A three-dimensional structural diagram of the chip mounting base;

[0023] Figure 5 A schematic diagram of the open end structure of the chip mounting base;

[0024] Figure 6 This is a cross-sectional structural diagram of an automotive intake pressure sensor. Detailed Implementation

[0025] like Figures 1-6 As shown, this utility model includes an automotive intake air pressure sensor, which includes: a housing 1, an air nozzle 2, an external interface 3, a cover plate 4, a printed circuit board 5, a chip mounting base 6, a sensor chip 7, and an external interface terminal 31.

[0026] The chip mounting base 6 is a barrel-shaped structure with one end open and the other end closed, and a through hole 63 for pins is opened at the bottom of the barrel.

[0027] An installation cavity is provided inside the housing 1, and a gas medium inlet 11 is provided at the bottom of the installation cavity. The printed circuit board 5 and the chip mounting base 6 are arranged adjacent to each other in the installation cavity; the open end of the chip mounting base 6 faces the gas medium inlet 11 and communicates with the gas medium inlet 11, and the open end of the chip mounting base 6 is fixedly connected to the inner cavity of the housing 1.

[0028] The connection between the chip mounting base 6 and the inner cavity of the housing 1 is achieved based on existing connection structures or technologies. For example, the open end of the chip mounting base 6 is designed with external threads, and the inner cavity of the housing 1 is provided with an annular groove with internal threads. The two are connected together using a threaded connection, achieving a gas path seal without the need for sealant. To reduce process complexity, in this embodiment, both the open end of the chip mounting base 6 and the housing 1 are made of PPS plastic, achieving a sealed connection using existing technologies such as ultrasonic welding. This also eliminates the need for additional sealant or other structures to achieve a gas path seal, effectively simplifying the processing steps. Figure 5 and Figure 6 As shown, the open end of the chip mounting base 6 is configured as an annular convex structure 62 for connecting the chip mounting base 6 to the housing 1.

[0029] In practical applications, the diameter of the opening end of the chip mounting base 6 is designed to be larger than the diameter of the gas medium inlet 11. During installation, the two are set concentrically to ensure that the chip mounting base 6 can completely enclose the gas medium inlet 11, so that the gas medium entering from the gas channel 21 can completely enter the interior of the chip mounting base 6. This can effectively prevent other electronic components of the sensor from being damaged by harmful substances in the gas medium.

[0030] The sensor chip 7 is mounted on the bottom of the chip mounting base 6. The specific mounting method is based on existing technology. In this embodiment, the sensor chip 7 is fixed to the chip mounting base 6 by soldering. The chip pins 71 are located on the back side of the pressure sensing surface of the sensor chip. The chip pins 71 pass through the bottom of the chip mounting base 6 via the pin through-hole 63 and are electrically connected to the printed circuit board 5. The printed circuit board 5 is soldered to the outer casing 1 and the chip pins 71 by soldering or other methods in the prior art.

[0031] The pressure sensing surface of the sensor chip 7 faces the gas medium inlet 11. The gas nozzle 2 is mounted on the housing 1, and the gas channel 21 inside the gas nozzle 2 is connected to the opening end of the chip mounting base 6 via the gas medium inlet 11.

[0032] After the gas medium enters the nozzle 2, it is guided by the gas channel 21 from the gas medium inlet 11 into the inner cavity of the chip mounting base 6, and acts on the pressure sensing surface of the sensor chip 7 at the bottom of the chip mounting base 6 to realize pressure measurement. The measurement data is transmitted to the printed circuit board 5 via the pin, and then transmitted to the outside via the external interface terminal 31. The specific details are based on existing technology.

[0033] The pressure sensing surface of the sensor chip 7 faces the gas medium inlet 11, so during the measurement process, the sensor chip 7 will be pressed tightly against the bottom of the chip mounting base 6. This can effectively seal the pins with the through hole 63, thereby ensuring that the printed circuit board is not exposed to the gas medium and improving the sensor's lifespan.

[0034] The bottom of the chip mounting base 6 is provided with columnar feet 61, and the circuit board is provided with positioning through holes. The columnar feet 61 pass through the positioning through holes and are fixedly connected to the circuit board. In this application, the positioning through holes on the circuit board and the columnar feet 61 are used to achieve the matching and positioning between the printed circuit board 5 and the chip mounting base 6, thereby improving the installation efficiency. Then, the columnar feet are fixed to the printed circuit board 5 by ultrasonic welding.

[0035] like Figure 3 As shown, the mounting cavity is a stepped cavity, including: a first cavity 12, a second cavity 13, and a third cavity 14 whose dimensions gradually increase from the inside to the outside and are interconnected; a chip mounting base 6 is disposed in the first cavity 12, and a printed circuit board 5 is disposed in the second cavity 13; a cover plate 4 is disposed in the third cavity 14. Both the cover plate 4 and the outer shell 1 are made of PPS plastic and are connected based on existing technologies such as ultrasonic welding.

[0036] External interface 3 is located on housing 1, and external interface 3 is interconnected with mounting cavity via terminal guide 15. External interface terminal 31 is located in external interface 3, and external interface terminal 31 is connected to printed circuit board 5 via terminal guide 15 to provide external data interface for pressure sensor. The specific implementation method is based on existing technology.

[0037] In this application, the outer shell 1, the external interface 3, and the air nozzle 2 are integrally molded, which is achieved based on existing injection molding technology, thereby improving the structural airtightness and simplifying the process.

[0038] After using the technical solution of this utility model, the pressure measuring device sensor chip 7 is set in the inner cavity of the chip mounting base 6, facing the direction of the medium pressure. The circuit connection pins of the sensor chip 7 are designed on the back of the sensor chip 7, and other electronic components are arranged outside the chip mounting base 6, ensuring that the gas medium entering the inner cavity of the chip mounting base 6 will not affect other devices. This application designs the structural cooperation between the chip mounting base 6 and the outer shell 1 to construct a relatively independent pressure sensing cavity, which not only improves the service life of the sensor, but also does not increase the cost.

Claims

1. An automotive intake pressure sensor, comprising: The housing, air nozzle, printed circuit board, and sensor chip are characterized in that they further include: a chip mounting base, wherein the chip mounting base is a barrel-shaped structure with one end open and the other end bottomed, and through holes for pins are provided at the bottom of the barrel; An installation cavity is provided inside the outer shell, and a gas medium inlet is provided at the bottom of the installation cavity; The printed circuit board and the chip mounting base are arranged adjacent to each other in the mounting cavity; the open end of the chip mounting base is fixedly connected to the inner wall of the housing and communicates with the gas medium inlet; The sensor chip is disposed on the bottom of the chip mounting base, and the chip pins are disposed on the back side of the pressure sensing surface of the sensor chip; the chip pins pass through the bottom of the chip mounting base through the pins via through holes and are electrically connected to the printed circuit board; the pressure sensing surface of the sensor chip faces the gas medium inlet. The air nozzle is disposed on the housing, and the gas channel inside the air nozzle is connected to the opening end of the chip mounting base via the gas medium inlet.

2. The automotive intake pressure sensor according to claim 1, characterized in that: The diameter of the opening end of the chip mounting base is larger than the diameter of the gas medium inlet, and the two are concentrically arranged.

3. The automotive intake pressure sensor according to claim 1, characterized in that: The bottom of the chip mounting base is provided with columnar feet, and the circuit board is provided with positioning through holes. The columnar feet pass through the positioning through holes and are fixedly connected to the circuit board.

4. The automotive intake pressure sensor according to claim 1, characterized in that: The opening end of the chip mounting base is configured as an annular convex structure.

5. The automotive intake pressure sensor according to claim 1, characterized in that: The mounting cavity is a stepped cavity, comprising a first cavity, a second cavity, and a third cavity whose dimensions gradually increase from the inside out and are interconnected; the chip mounting base is disposed in the first cavity, and the printed circuit board is disposed in the second cavity.

6. The automotive intake pressure sensor according to claim 5, characterized in that: It also includes a cover plate disposed in the third cavity.

7. The automotive intake pressure sensor according to claim 1, characterized in that: It also includes: an external interface and external interface terminals, wherein the external interface is disposed on the housing and is interconnected with the mounting cavity via a terminal guide channel; the external interface terminals are disposed in the external interface and are connected to the printed circuit board via the terminal guide channel.

8. The automotive intake pressure sensor according to claim 7, characterized in that: The outer shell, the external interface, and the air nozzle are integrally formed.

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