Small-sized packaged differential pressure sensor

Abstract

The utility model relates to the technical field of gas pressure difference measurement, in particular to a small-sized packaged differential pressure sensor, which comprises a base, a thin film MEMS (micro-electromechanical system) chip is mounted on the base, a first air pressure hole is arranged on the base and communicated with a resistance strain gauge of the thin film MEMS chip, the small-sized packaged differential pressure sensor further comprises a shell, the shell is fixedly mounted on the base, and the thin film MEMS chip is arranged on the shell. A second air pressure hole is formed in the top of the shell, and the projection position of the second air pressure hole in the vertical direction does not coincide with a resistance strain gauge of the thin film MEMS chip. According to the utility model, through the staggered design of the double air pressure holes, the high-sensitivity response of the thin film MEMS chip, the reliability guarantee of the sealing structure and the pin layout adaptive to automatic production, the sensor realizes the differential pressure measurement function with miniaturization, high precision and strong anti-interference, and solves the problems of large size and limited installation space of the traditional sensor.

Description

Technical Field

[0001] This utility model relates to the field of gas differential pressure measurement technology, specifically to a small packaged differential pressure sensor. Background Technology

[0002] Gas differential pressure sensors are used to measure the pressure difference between two pipes or cavities and have wide applications in fields such as ventilators and anesthesia machines. However, existing traditional differential pressure sensors are typically large and need to be integrated onto a PCB board and placed inside the device cavity for measurement. This limited installation space restricts their application in demanding scenarios such as medical applications, and they are particularly unsuitable for scenarios requiring high precision, high stability, and miniaturized integration. Therefore, there is an urgent need for a miniaturized differential pressure sensor to overcome the limitations of existing technologies. Utility Model Content

[0003] The purpose of this invention is to provide a small-sized packaged differential pressure sensor that solves the problem of limited installation space in the prior art through structural optimization.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a small packaged differential pressure sensor, including a base, on which a thin-film MEMS chip is mounted, and a first pressure hole is provided on the base, which is connected to the resistance strain gauge of the thin-film MEMS chip. It also includes a housing, which is fixedly mounted on the base, and a second pressure hole is provided on the top of the housing. The vertical projection position of the second pressure hole does not coincide with the resistance strain gauge of the thin-film MEMS chip.

[0005] Preferably, it also includes a sealing ring, which is embedded in the base and is flush with the bottom surface of the base, and the first air pressure hole is located inside the sealing ring.

[0006] Preferably, the communication pins of the thin-film MEMS chip are mounted on the bottom surface of the base and arranged in a matrix.

[0007] Preferably, the communication pin is coplanar with the bottom surface of the base.

[0008] Preferably, the communication pins and the sealing rings are located on both sides of the base.

[0009] Preferably, the diameter of the second air pressure hole is not less than the diameter of the first air pressure hole.

[0010] Compared with the prior art, this utility model provides a small packaged differential pressure sensor, which has the following advantages:

[0011] 1. Thin-film MEMS chips have high sensitivity and low drift, ensuring measurement accuracy;

[0012] 2. The separate design of the sealing ring and pins improves sealing performance and anti-interference capability;

[0013] 3. The communication pin matrix arrangement is adapted to SMT automated production, improving installation efficiency;

[0014] 4. The staggered layout of the dual air pressure holes reduces the impact of mechanical stress on the chip and extends its service life;

[0015] 5. The overall structure is compact and small in size, making it suitable for space-constrained scenarios. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the bottom of the present invention;

[0018] Figure 3 This is a cross-sectional view of the present invention.

[0019] Explanation of reference numerals in the attached diagram: 1. Base; 11. First air pressure hole; 2. Thin-film MEMS chip; 3. Housing; 31. Second air pressure hole; 4. Sealing ring; 5. Communication pin. Detailed Implementation

[0020] The technical solutions of the present utility model will now be described with reference to the accompanying drawings in the embodiments of the present utility model:

[0021] like Figure 1-3 As shown: This utility model provides a small packaged differential pressure sensor, including a base 1, on which a thin-film MEMS chip 2 is mounted. The base 1 has a first pressure port 11, which communicates with the resistance strain gauge of the thin-film MEMS chip 2. It also includes a housing 3, which is fixedly mounted on the base 1. The top of the housing 3 has a second pressure port 31. The vertical projection of the second pressure port 31 does not coincide with the resistance strain gauge of the thin-film MEMS chip 2, avoiding direct pressure impact on the sensitive element and thus reducing mechanical stress damage to the chip. The diameter of the second pressure port 31 is not smaller than the diameter of the first pressure port 11 to ensure pressure balance.

[0022] It also includes a sealing ring 4, which is embedded in the base 1 and is flush with the bottom surface of the base 1. The first air pressure hole 11 is located inside the sealing ring 4 to ensure tight contact with the sealing surface of the external equipment and to ensure sealing under high pressure.

[0023] The communication pins 5 of the thin-film MEMS chip 2 are mounted on the bottom surface of the base 1 and arranged in a matrix. The communication pins 5 are flush with the bottom surface of the base 1, which facilitates automated SMT installation. The chip is connected to the PCB board through LGA packaging to ensure stable signal transmission and heat dissipation. The communication pins 5 and the sealing rings 4 are located on both sides of the base 1 to avoid the impact of heat conduction on the sealing performance during the soldering process and to reduce signal interference.

[0024] The working principle of this utility model:

[0025] This differential pressure sensor measures the pressure difference between two independent pressure chambers and converts it into an electrical signal output using the deformation characteristics of a thin-film MEMS chip. The specific process is as follows:

[0026] Air pressure input and isolation

[0027] The first pressure port 11 and the second pressure port 31 are respectively connected to two pressure sources (such as pipes or cavities) to be measured. The first pressure port 11 is connected to the cavity where the resistance strain gauge of the thin-film MEMS chip 2 is located through the channel of the base 1, while the second pressure port 31 is connected to the cavity on the other side of the thin-film MEMS chip 2 through the outer shell 3. The vertical projection misalignment design of the two ports (the second pressure port is not directly aligned with the resistance strain gauge) avoids the airflow directly impacting the sensitive area and reduces mechanical stress damage to the chip.

[0028] Differential pressure sensing and signal conversion

[0029] When there is a pressure difference between the two sides, the elastic film (resistance strain gauge area) of the thin-film MEMS chip deforms due to the pressure difference, and the resistance value changes. This change is converted into a voltage signal output, thereby accurately reflecting the pressure difference between the two points.

[0030] Structural optimization and stability assurance

[0031] Sealing design: The sealing ring 4 is embedded in the bottom surface of the base 1 and fits tightly with the sealing surface of the external equipment to ensure airtightness under high pressure and prevent gas leakage from interfering with the measurement.

[0032] Anti-interference layout: The communication pin 5 and the sealing ring are placed on the two sides of the base to reduce the impact of welding heat conduction on the sealing performance, and at the same time avoid electromagnetic interference during signal transmission.

[0033] Heat dissipation and installation optimization: The coplanar design of communication pin 5 and base 1 is adapted to SMT automated soldering, improving production efficiency; the metal base has both structural strength and heat dissipation capacity, avoiding zero-point drift caused by heat accumulation.

[0034] This invention achieves miniaturized, high-precision, and highly interference-resistant differential pressure measurement by employing a dual-pressure-hole misalignment design, a high-sensitivity response of a thin-film MEMS chip, a reliable sealing structure, and a pin layout adapted for automated production. This solves the problems of large size and limited installation space of traditional sensors.

[0035] The above embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A small packaged differential pressure sensor, comprising a base (1), wherein a thin-film MEMS chip (2) is mounted on the base (1), and a first pressure hole (11) is provided on the base (1), the first pressure hole (11) being connected to a resistance strain gauge of the thin-film MEMS chip (2), characterized in that: It also includes a housing (3), which is fixedly installed on the base (1). The top of the housing (3) is provided with a second air pressure hole (31), and the vertical projection position of the second air pressure hole (31) does not coincide with the resistance strain gauge of the thin film MEMS chip (2).

2. The miniature packaged differential pressure sensor according to claim 1, characterized in that: It also includes a sealing ring (4), which is embedded in the base (1) and is flush with the bottom surface of the base (1). The first air pressure hole (11) is located inside the sealing ring (4).

3. The miniature packaged differential pressure sensor according to claim 1, characterized in that: The communication pins (5) of the thin-film MEMS chip (2) are mounted on the bottom surface of the base (1) and arranged in a matrix.

4. The miniature packaged differential pressure sensor according to claim 3, characterized in that: The communication pin (5) is on the same plane as the bottom surface of the base (1).

5. The miniature packaged differential pressure sensor according to claim 3, characterized in that: The communication pin (5) and the sealing ring (4) are located on both sides of the base (1).

6. The miniature packaged differential pressure sensor according to claim 1, characterized in that: The diameter of the second air pressure hole (31) is not less than the diameter of the first air pressure hole (11).

Images