Micro-differential pressure sensor with double-air-tap structure

Abstract

The utility model provides the micro-differential pressure sensor with the double-air-tap structure, the micro-differential pressure sensor not only can realize a dustproof function, but also has a detachable dustproof structure, so that a dustproof part can be conveniently replaced or dedusted. The micro differential pressure sensor comprises a sensor frame body, a first air tap, a second air tap, a micro differential pressure sensor chip and a dustproof baffle, the first air tap and the second air tap are connected with connecting caps respectively, the connecting caps are hollow and are sequentially provided with hollow communicating sections and threaded connecting sections from top to bottom, and the inner diameter of the communicating sections is smaller than that of the threaded connecting sections; the first air tap and the second air tap are in threaded connection with the threaded connection section, and the dustproof baffle is clamped between the first air tap / the second air tap and the connection cap and separates the communication section from the first air channel / the second air channel.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure sensors, in particular to a micro differential pressure sensor with a double air nozzle structure. Background Art

[0002] A dual-nozzle micro-differential pressure sensor is a sensor used to measure a small difference between two pressures. Existing micro-differential pressure sensors, for example, are structures disclosed in patent publication number CN209820673U, which include a sensor housing body on which two air inlet nozzles are provided. The first air inlet nozzle is connected to the internal cavity of the sensor and applies pressure to the front of the sensor chip arranged in the internal cavity, and the other air nozzle applies pressure to the back of the sensor chip through the rear cavity structure and the vent. With this design, the sensor chip can output the difference in pressure at both ends and output it through the pins.

[0003] Since the chip is directly connected to the outside, it is easily affected by impurities and dust in the external environment, which will cause the chip accuracy to decrease over time. For this reason, the current dual-nozzle micro-differential pressure sensor uses a dust baffle to block the dust. For example, the patent with announcement number CN209820680U sets a dust baffle in the above-mentioned internal cavity to block the dust. However, since the various packaging components of the sensor are generally sealed with glue, the above-mentioned dustproof structure is difficult to replace the dust baffle and clean the dust. Over time, it will lead to poor gas circulation, which will still affect the sensor accuracy. Utility Model Content

[0004] In view of the problem that the dust baffle in the existing micro-differential pressure sensor with a double air nozzle structure is not easy to clean or replace, the utility model provides a micro-differential pressure sensor with a double air nozzle structure, which not only can realize the dustproof function, but also its dustproof structure can be disassembled, thereby facilitating the replacement or cleaning of the dustproof components.

[0005] The technical solution is as follows: a micro differential pressure sensor with a double air nozzle structure, comprising a sensor frame body, air nozzle 1, air nozzle 2, a micro differential pressure sensor chip and a dust baffle, wherein a mounting cavity is provided inside the sensor frame body, the micro differential pressure sensor chip is mounted in the mounting cavity and its front side is exposed in the mounting cavity, the air nozzle 1 and the air nozzle 2 are respectively connected to the sensor frame body, an air channel 1 is provided in the middle of the air nozzle 1 and is connected to the mounting cavity through the air channel 1, and an air channel 1 is provided in the middle of the air nozzle 2 There is air duct two, and the air duct two is connected to the back side of the micro-differential pressure sensor chip, and is characterized in that: the air nozzle one and the air nozzle two are respectively connected with connecting caps, the connecting caps are hollow inside and are provided with hollow connecting sections and threaded connecting sections from top to bottom, the inner diameter of the connecting section is smaller than the inner diameter of the threaded connecting section, the air nozzle one and the air nozzle two are respectively threadedly connected to the threaded connecting sections, and the dust baffle is clamped between the air nozzle one / air nozzle two and the connecting caps and separates the connecting section from the air duct one / air duct two.

[0006] It is further characterized by:

[0007] The sensor frame body comprises a substrate, a pad is provided on the substrate, and the micro differential pressure sensor chip is bonded to the substrate and connected to the pad via a connecting wire;

[0008] The mounting cavity is located at the bottom of the substrate, and the substrate is provided with a first air hole, and the first air channel is connected to the mounting cavity through the first air hole. The substrate is also provided with a second air hole, and the second air hole is arranged corresponding to the back side of the micro differential pressure sensor chip, and the second air hole is connected to the second air channel;

[0009] The micro differential pressure sensor chip includes a MEMS chip and an ASIC chip;

[0010] The width of the dust baffle is larger than the inner diameter of the connecting section and smaller than the inner diameter of the threaded connection section;

[0011] The connecting cap is in the shape of a truncated cone;

[0012] A bottom cover is provided at the bottom of the sensor frame body.

[0013] The beneficial effects of the utility model are as follows: the dust baffle is clamped between the connecting cap and the air nozzle, and the dust baffle is located in the air intake passage of the sensor to play a dust-proof role. At the same time, the connecting cap and the air nozzle are threadedly connected, so the connecting cap can be unscrewed when necessary and the dust baffle can be taken out for replacement or cleaning, which is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the utility model;

[0015] Figure 2 This is a schematic diagram of the bottom structure of the utility model;

[0016] Figure 3 This is a schematic diagram of the internal structure of the utility model;

[0017] Figure 4 This is a schematic diagram of the connection between the gas nozzle and the connecting cap;

[0018] Figure 5 This is the exploded diagram of the connection between the air nozzle and the connecting cap. DETAILED DESCRIPTION

[0019] like Figure 1 , Figure 4 and Figure 5 A micro differential pressure sensor with a double air nozzle structure is shown, which includes a sensor frame body 1, an air nozzle 1 2, an air nozzle 2 3, a micro differential pressure sensor chip (including a MEMS chip 4 and an ASIC chip 5) and a dust baffle 6. A mounting cavity 7 is provided inside the sensor frame body 1, and the micro differential pressure sensor chip is installed in the mounting cavity 7 and its front side is exposed in the mounting cavity 7. The air nozzle 1 2 and the air nozzle 2 3 are respectively connected to the sensor frame body 1, and an air channel 1 21 is provided in the middle of the air nozzle 1 and is connected to the mounting cavity 7 through the air channel 1 21. An air channel 2 31 is provided in the middle of the air nozzle 2 3, and the air channel 2 31 is connected to the micro differential pressure sensor chip. The back side of the pressure sensor chip is connected, and the air nozzle 1 2 and the air nozzle 2 3 are respectively connected with a connecting cap 8, which is truncated cone-shaped and can stably connect the air pipe. The connecting cap 8 is hollow inside and is provided with a hollow connecting section 81 and a threaded connecting section 82 from top to bottom. The inner diameter of the connecting section 81 is smaller than the inner diameter of the threaded connecting section 82, and the air nozzle 1 2 and the air nozzle 2 3 are respectively connected with the threaded connecting section 82, and the width of the dust baffle 6 is larger than the inner diameter of the connecting section 81 and smaller than the inner diameter of the threaded connecting section 82. The dust baffle 6 is clamped between the air nozzle 1 2 / air nozzle 2 3 and the connecting cap 8 and separates the connecting section 81 from the airway 1 21 / airway 2 31.

[0020] When the dust baffle needs to be replaced, you only need to unscrew the connecting cap to take out the dust baffle, place the new dust baffle in the connecting cap, and then screw the connecting cap onto the air nozzle. The air nozzle and the connecting cap can clamp the dust baffle between the two to fix it.

[0021] Specific, combined Figure 2 , Figure 3The sensor frame body 1 includes a substrate 11, a pad 12 is provided on the substrate 11, a micro differential pressure sensor chip is bonded to the substrate 11 and connected to the pad 12 through a connecting wire, and a bottom cover 15 is provided at the bottom of the sensor frame body 1. The mounting cavity 7 is located at the bottom of the substrate 11, a curved air hole 13 is provided on the substrate 11, and the air channel 1 21 is connected to the mounting cavity 7 through the air hole 13. The substrate 11 is also provided with an air hole 2 14, which is arranged corresponding to the back of the micro differential pressure sensor chip, and the air hole 2 14 is connected to the air channel 2 31.

[0022] When assembling the above components, pre-process the sensor frame body 1 to make it free of burrs. The sensor frame body 1 is mainly made of PPS material. The MEMS chip (a chip that uses four resistors to form a Wheatstone effect and changes the output voltage by different pressures) is glued into the frame body, with the back hole facing the air hole 2, and baked and cured. The ASIC chip (a chip that uses the voltage output by the MEMS chip to determine the output curve through the upper computer software and finally burns the data into the chip) is glued into the preset position and baked and cured. The chip glue used is micro-pressure glue, which greatly reduces the impact of glue on the chip. The two chips are connected to the internal pins of the frame body with gold wire according to the wiring. Glue is applied at the preset position and the bottom cover is attached. The double air nozzle (made of PPS) is pre-processed and connected to the frame body. Epoxy glue is applied at the connection to seal the product and bake and cure.

[0023] The above are only preferred specific implementations of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by anyone familiar with the technology within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A micro differential pressure sensor with a double air nozzle structure, comprising a sensor frame body, air nozzle 1, air nozzle 2, a micro differential pressure sensor chip and a dust baffle, wherein a mounting cavity is provided inside the sensor frame body, the micro differential pressure sensor chip is mounted in the mounting cavity and its front side is exposed in the mounting cavity, the air nozzle 1 and the air nozzle 2 are respectively connected to the sensor frame body, the air nozzle 1 is provided with an air channel 1 in the middle and communicates with the mounting cavity through the air channel 1, the air nozzle 2 is provided with an air channel 2 in the middle, and the air channel 2 is communicated with the back side of the micro differential pressure sensor chip, characterized in that: The air nozzle 1 and the air nozzle 2 are respectively connected with a connecting cap, the interior of the connecting cap is hollow and is provided with a hollow connecting section and a threaded connecting section from top to bottom, the inner diameter of the connecting section is smaller than the inner diameter of the threaded connecting section, the air nozzle 1 and the air nozzle 2 are respectively threadedly connected to the threaded connecting section, the dust baffle is clamped between the air nozzle 1 / air nozzle 2 and the connecting cap and separates the connecting section from the air duct 1 / air duct 2.

2. A micro differential pressure sensor with a double air nozzle structure according to claim 1, characterized in that: The sensor frame body comprises a substrate, a pad is provided on the substrate, and the micro differential pressure sensor chip is adhered to the substrate and connected to the pad via a connecting wire.

3. The micro differential pressure sensor with a double air nozzle structure according to claim 2, characterized in that: The mounting cavity is located at the bottom of the substrate, and a first air hole is provided on the substrate. The first air channel is connected to the mounting cavity through the first air hole. A second air hole is also provided on the substrate. The second air hole is arranged corresponding to the back side of the micro-differential pressure sensor chip, and the second air hole is connected to the second air channel.

4. A micro differential pressure sensor with a dual air nozzle structure according to any one of claims 1 to 3, characterized in that: The micro differential pressure sensor chip includes a MEMS chip and an ASIC chip.

5. A micro differential pressure sensor with a dual air nozzle structure according to any one of claims 1 to 3, characterized in that: The width of the dustproof baffle is larger than the inner diameter of the connecting section and smaller than the inner diameter of the threaded connection section.

6. A micro differential pressure sensor with a dual-valve structure according to any one of claims 1 to 3, characterized in that: The connecting cap is in a truncated cone shape.

7. A micro differential pressure sensor with a dual air nozzle structure according to any one of claims 1 to 3, characterized in that: A bottom cover is provided at the bottom of the sensor frame body.

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