A pressure sensing assembly

Abstract

A pressure sensing assembly comprises a circuit board, a pressure hole is formed through the circuit board, a plurality of electronic components are arranged on the front surface of the circuit board, a pressure chip is fixed to the front surface of the circuit board and communicated with the pressure hole, and a first side partition plate and a second side partition plate are fixed to the front surface of the circuit board in parallel, a second partition groove for accommodating a second partition rib is formed between the first side partition plate and the second side partition plate, the pressure chip and the electronic components are separated by the second partition groove, and the second partition groove is filled with a second sealant; a pressure chip protection glue is arranged on the pressure chip, and a circuit board protection glue is arranged outside the electronic components. The pressure sensing assembly can additionally provide sealing, avoid high-temperature exhaust gas from penetrating from one side of the pressure chip and eroding other electronic components, and increase the thickness of the circuit board protection glue through the side partition plate to completely cover other electronic components except the pressure chip.

Description

Technical Field

[0001] This application relates to the field of pressure sensor technology, and more specifically to a pressure sensing component. Background Technology

[0002] A differential pressure sensor is a sensor used to measure the difference between two pressures. It is typically used to measure the pressure difference between the front and rear ends of a device or component, with the most typical application being the measurement of the exhaust gas pressure difference between the front and rear passages of a car engine particulate filter. In existing technologies, nitrogen oxides and particulate matter, such as soot and water vapor, emitted by vehicle engines are prone to crystallization and freezing at low temperatures. The excessive pressure generated during particulate crystallization and freezing can damage the sensor chip. Simultaneously, nitrogen oxides react with water vapor to form an acidic solution, which easily corrodes the sensor chip and wiring. Therefore, it is best to isolate the sensor's pressure-sensing chip from contaminants. Hence, a differential pressure sensor is proposed to address the aforementioned problems.

[0003] Chinese patent application CN114993549A discloses a differential pressure sensor, which includes a pressure sensor housing. The pressure sensor housing includes a main housing with a mounting cavity inside. The lower end of the main housing has a first connector tube and a second connector tube. The first connector tube has a first pressure guiding channel, and the second connector tube has a second pressure guiding channel. The pressure core assembly includes a circuit board, a first pressure sensitive element for sensing the pressure difference between a first pressure of the fluid to be measured in the first connector tube and a reference pressure, and a second pressure sensitive element for sensing the pressure difference between a second pressure of the fluid to be measured in the second connector tube and the first pressure. The circuit board is located at the bottom of the mounting cavity, and the first and second pressure sensitive elements are both disposed on the upper side of the circuit board.

[0004] Because its circuit board is set perpendicular to the pressure connector tube, which is usually installed vertically, water vapor in the exhaust gas is difficult to expel when it accumulates in the pressure chamber, thus reducing measurement accuracy. In addition, there is no isolation between its high-pressure chamber (higher pressure) and the pressure core assembly, so the exhaust gas on the high-pressure side is at risk of corroding the circuit components. Furthermore, the pressure core is also exposed to the low-pressure side, and other electronic components are only isolated from the low-pressure side by a partition. Therefore, its corrosion resistance still has room for improvement.

[0005] The statements in this section are provided only as background information in relation to this application and may not constitute prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application provides a pressure sensing component that better isolates other electronic components, besides the pressure chip, from harsh media such as high-temperature exhaust gases.

[0007] To achieve the above objectives, this application provides the following technical solution: a pressure sensing component, comprising:

[0008] The circuit board has pressure holes that pass through both sides of the circuit board, and multiple electronic components are arranged on its front side;

[0009] The pressure chip is sealed to the front of the circuit board on one side and connected to the pressure hole.

[0010] A first side partition and a second side partition are fixed to the front of the circuit board at intervals. A second partition groove is formed between the first side partition and the second side partition to accommodate the second partition rib. The pressure chip and the electronic components are separated by the second partition groove, which is filled with a second sealant. The pressure chip is covered with pressure chip protective adhesive, and the electronic components are covered with circuit board protective adhesive.

[0011] Preferably, the first side partition and / or the second side partition are made of multiple layers of glue stacked together.

[0012] Preferably, the first side partition and / or the second side partition are integrally connected to the second side cover, and the second side cover is provided with a through hole that communicates with the second partition groove to allow the second sealant to pass through.

[0013] Preferably, the plurality of electronic components include a conditioning chip and solder pads.

[0014] Preferably, the pressure chip protective adhesive is surrounded by an adhesive frame, which is fixed to the circuit board. Attached Figure Description

[0015] Figure 1 This is a bottom view of a differential pressure sensor according to a preferred embodiment of this application;

[0016] Figure 2 The differential pressure sensor of a preferred embodiment of this application is along Figure 1 The planar sectional view of AA shown;

[0017] Figure 3 This is a right view of a differential pressure sensor according to a preferred embodiment of this application;

[0018] Figure 4 The differential pressure sensor of a preferred embodiment of this application is along Figure 3 The planar sectional view of BB shown;

[0019] Figure 5 The differential pressure sensor of a preferred embodiment of this application is along Figure 3 The planar sectional view of CC shown;

[0020] Figure 6 The differential pressure sensor of a preferred embodiment of this application is along Figure 3 The planar sectional view of DD shown;

[0021] Figure 7The differential pressure sensor of a preferred embodiment of this application is along Figure 3 A three-dimensional sectional view of BB shown in the figure;

[0022] Figure 8 This is a perspective view of a differential pressure sensor according to a preferred embodiment of this application (side cover omitted);

[0023] Figure 9 This is a perspective view of a differential pressure sensor according to a preferred embodiment of this application (side cover 2 omitted);

[0024] In the diagram: 1. Main housing; 01a. High-pressure chamber; 01b. Low-pressure chamber; 01c. Side wall; 01d. Recess; 01e. Trumpet mouth; 101. High-pressure connector pipe; 102. Low-pressure connector pipe; 103. Connecting part; 104. Button; 106. Baffle; 107. Inclined partition; 408. Pressure hole; 110. First sealing groove; 111. First partition groove; 112. Second sealing groove; 113. Second partition groove; 114. Positioning stop; 108. First gap; 2. Side cover one; 201. First side cover body; 202. 203. First flange; 301. Second side cover body; 302. Second flange; 303. Second rib; 304. Steel ball hole; 4. Pressure sensing component; 40. Circuit board protective adhesive; 401. Circuit board; 402. Pressure chip; 403. Adhesive frame; 404. Pressure chip protective adhesive; 406. Conditioning chip; 407. Solder pad; 40a. Front part; 40b. Back part one; 40c. Back part two; 40d. Back part three; 5. Pin; 6. Side partition; 105. Side plate; Detailed Implementation

[0025] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the following description, the same reference numerals are used to denote the same or equivalent elements, and repeated descriptions are omitted.

[0026] In the description of this application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] Furthermore, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] It should also be further understood that the term "and / or" as used in this application specification and the corresponding claims refers to any combination of one or more of the listed items and all possible combinations.

[0029] like Figures 1 to 3 As shown. In a preferred embodiment of this application, the differential pressure sensor includes a housing, a high-pressure connector tube 101, a low-pressure connector tube 102, and a pressure sensing component 4. The inner cavity of the housing is separated by a side plate 105 (see...). Figure 8 The side plate 105 is divided into a high-pressure chamber 01a and a first chamber by a sloping partition 107. The first chamber includes a pressure core assembly mounting cavity and a low-pressure chamber 01b that are connected to each other. The pressure core assembly mounting cavity and the low-pressure chamber 01b are located on the left and right sides of the side plate 105, respectively.

[0030] The low-pressure connector pipe 102 is connected upward to the low-pressure chamber 01b, and is used to introduce a first pressure P1 into the low-pressure chamber 01b. The high-pressure connector pipe 101 is connected upward to the high-pressure chamber 01a, and is located in front of the low-pressure connector pipe 102, for introducing a second pressure P2 into the high-pressure chamber 01a.

[0031] The pressure sensing component 4 is disposed within the mounting cavity of the pressure core component, and includes at least a circuit board 401 and a pressure chip 402. The circuit board 401 is vertically arranged front to back, and has a pressure hole 408 that extends left to right. One side of the pressure chip 402 is sealed and fixed to the circuit board 401. The low-pressure chamber 01b is connected to the corresponding left and right sides of the pressure chip 402 through the pressure hole 408.

[0032] Thus, the first pressure P1 and the second pressure P2 are respectively connected to both sides of the pressure chip 402. The change in resistance caused by the pressure difference is transmitted to the outside of the circuit board through the measuring circuit on the circuit board 402 and then through the pin 5 (see...). Figure 7 Export.

[0033] The differential pressure sensor in this embodiment, by vertically arranging the circuit board and pressure chip of the pressure core assembly, enables water entering the housing to be discharged more smoothly, reducing water accumulation in the cavity.

[0034] In some other embodiments, the lower part of the sidewall of the inclined baffle 107 located on the low-pressure chamber 01b side extends obliquely toward the low-pressure chamber 01b side. This allows water accumulated in the low-pressure chamber 01b to be discharged more smoothly to the bottom of the low-pressure chamber 01b through the low-pressure connector pipe 102. This is effective when the high-pressure connector pipe 101 and the low-pressure connector pipe 102 are installed at an oblique angle (within 20° of the vertical line).

[0035] The rear end of the housing can be connected to a front-to-back extending plug 104. A pin 5 is embedded in the plug 104, its front end electrically connected to the pressure sensing component 4, and its rear end extending into the inner cavity of the plug 104. Multiple front-to-back extending guide ribs (not marked) can be provided in the inner cavity of the plug 104. The front end of the housing can be connected to a connecting part 103 for fastening to an external device. The connecting part 103 has a connecting hole, and a bushing (not marked) is provided inside the connecting hole.

[0036] In some other embodiments, the pressure chip 402 is covered with a pressure chip protective adhesive 404. An adhesive frame 403 is provided around the pressure chip protective adhesive 404. The adhesive frame 403 is fixed to the circuit board 401. A second gap of height H2 is left between the end of the adhesive frame 403 away from the circuit board 401 and the inner wall of the housing, wherein H2 is greater than or equal to 2 mm.

[0037] In some other embodiments, a baffle 106 protrudes from the top inner wall of the low-pressure chamber 01b to reduce the impact and erosion of the pressure core by the high-pressure exhaust gas. A third gap is left between the lower end of the baffle 106 and the side wall of the inclined baffle 107 located on the side of the low-pressure chamber 01b. Preferably, the distance H3 between the lower end of the baffle 106 and the side wall of the inclined baffle 107 located on the side of the low-pressure chamber 01b is greater than or equal to 5 mm.

[0038] Please refer to the following: Figure 4 In some other embodiments, the lower part of the side wall 01c of the side plate 105 located on the side of the low-pressure chamber 01b extends obliquely toward the pressure core assembly mounting cavity, which further facilitates the flow of water accumulated in the low-pressure chamber 01b to the bottom of the low-pressure chamber 01b and discharge through the low-pressure connector pipe 102.

[0039] Please refer to the following: Figure 5 In some other embodiments, a first gap 108 is provided between the lower part of the circuit board 401 and the sidewall of the side plate 105 facing the pressure core assembly mounting cavity, to prevent water from remaining between the back side of the circuit board 401 (the side facing the low-pressure cavity 01b) and the housing due to capillary action. Preferably, the thickness of the first gap 108 is greater than or equal to 2 mm.

[0040] Please refer to the following: Figure 6 , Figure 7In some other embodiments, a flared opening 01e is formed within the low-pressure chamber 01b, axially communicating with the pressure hole 408. The flared opening 01e is located on the upper front side of the low-pressure chamber 01b. The end of the flared opening 01e furthest from the pressure hole 408 gradually widens compared to the other end furthest from the pressure hole 408. This allows water accumulated on the low-pressure side of the pressure chip 402 to drain smoothly from the pressure chip 402 to the bottom while ensuring that the other side of the side plate 105 is vertical and facilitates the installation of the pressure sensing component 4.

[0041] Please refer to the following: Figure 8 In some other embodiments, the lower end of the side wall 01c of the side plate 105 located on the low-pressure chamber 01b side is recessed towards the pressure core assembly mounting cavity to form a recess 01d. The lower edge of the recess 01d smoothly transitions to the upper edge of the low-pressure connector pipe 102. Compared to the neck formed between the low-pressure connector pipe and the low-pressure chamber due to the transition in orifice diameter in the prior art, drainage can be made smoother.

[0042] Please refer to the following: Figure 1 , Figure 6 and Figure 9 In some other embodiments, preferably, the lower rear end 109 of the high-pressure chamber 01a extends to the upper rear edge of the high-pressure connector tube 101. This allows water accumulated in the high-pressure chamber 01a to be drained more smoothly. Preferably, the lower rear end 109 of the high-pressure chamber 01a is directly opposite the lower front corner 409 of the circuit board 401, that is, the lower rear end 109 of the high-pressure chamber 01a extends horizontally to the lower front corner 409. This ensures that the high-pressure chamber 01 has a relatively large cross-section in the section perpendicular to the left and right direction, which further benefits the front side of the pressure chip 402 (the side closer to the high-pressure chamber 01a).

[0043] After the above measures are implemented in combination, the water accumulated in both the low-pressure chamber and the high-pressure chamber can be almost completely drained.

[0044] Please see Figure 7 , Figure 8 and Figure 9 In some other embodiments, the housing may include a main housing 1 with openings on the left and right sides, and side covers 2 and 3 respectively fixed and sealed to the left and right sides thereon, which may be made of plastic.

[0045] A first sealing groove 110 is formed by recessing the edges of the openings on the left and right sides of the main housing 1 corresponding to the low-pressure chamber 01b. A first partition groove 111 is formed by recessing the left and right corresponding ends of the inclined partition 107. The side cover 2 includes a first side cover body 201. The edge of the first side cover body 201 protrudes towards the main housing 1 to form a first flange 202 that inserts into the first sealing groove 110. The front and rear center portions of the first side cover body 201 protrude towards the main housing 1 to form first ribs 203 that insert into the first partition groove 111. A first sealant is provided in the first sealing groove 110 and the first partition groove 111. The side cover 2 and the main housing 1 are bonded and sealed with the first sealant, which, after bonding and sealing, can separate the first cavity and the low-pressure chamber 01b from the side.

[0046] The circuit board 401 has electronic components such as a conditioning chip 406 and solder pads 407 on the rear side away from the side plate 105. One end of the pin 5 is connected to the solder pad 407 on the circuit board 401 via a wire. These electronic components are covered with a layer of circuit board protective adhesive 40 to protect them and reduce the corrosion of the electronic components by the high-pressure exhaust gas.

[0047] In some other embodiments, a second side partition 62 is disposed directly opposite the front side of the first side partition 61. A second partition groove 113 is formed between the first side partition 61 and the second side partition 62. A second flange 302 is formed by recessing the edge of the opening on the left and right sides of the main housing 1 corresponding to the low-pressure chamber 01b. The second side cover 3 includes a second side cover body 301. The edge of the second side cover body 301 protrudes towards the main housing 1 to form a second flange 302 that inserts into the second sealing groove 112. The front and rear middle parts of the second side cover body 301 protrude towards the main housing 1 to form a second rib 303 that inserts into the second partition groove 113. By bonding and sealing the second partition groove formed between the two side partitions and the second side cover rib 303 with a second sealant, electronic components other than the pressure chip 402 can be isolated from the high-pressure exhaust gas, thereby further reducing the corrosion of electronic components by the high-pressure exhaust gas.

[0048] In some other embodiments, the second side cover body 301 has a ball hole 304, which faces the left and right inwards and is directly opposite the front part 40a of the circuit board protective adhesive 40.

[0049] In some other embodiments, the front end of the side plate 105 protrudes into the pressure core assembly mounting cavity to form a positioning stop 114. The positioning stop 114 abuts against the front end of the circuit board 401 rearward.

[0050] In some other embodiments, preferably, the rear end of the circuit board protective adhesive 40 abuts against the inner wall of the main housing 1. The front end of the circuit board protective adhesive 40 abuts against a first side partition 61. One left and one right end of the first side partition 61 abuts against the side surface of the circuit board 401 away from the side plate 105. In this way, when the circuit board protective adhesive 40 is applied to the circuit board 401 (with the circuit board 401 temporarily facing upwards), it is convenient to restrict the curing of the circuit board protective adhesive 40.

[0051] In other embodiments, preferably, at least one groove is provided on the side wall of the side plate 105 facing the pressure core assembly mounting cavity. Circuit board protective adhesive 40 extends along the groove to the left and right opposite sides of the circuit board 401. Figure 7 The diagram shows three back panel portions: 40b (first), 40c (second), and 40d (third), each formed by a groove. These grooves communicate with one side of the front side of the circuit board 401; that is, the formed back panel portions 40b (first), 40c (second), and 40d (third) are integrally connected to the front panel 40a, but are located on opposite sides of the circuit board 401. This allows the back panel portions to be placed between the circuit board and the inner wall of the housing, thereby increasing the shock resistance of the circuit board 401. Furthermore, when electronic components are located on the back side of the circuit board 401, these back-side electronic components can be protected by being housed within these grooves.

[0052] In some other embodiments, preferably, the first side partition 61 and / or the second side partition 62 are formed by stacking multiple layers of adhesive. In other embodiments, the first side partition 61 and / or the second side partition 62 are also fixed to the circuit board 401. In other embodiments, the first side partition 61 and / or the second side partition 62 can also be integrally connected to the second side cover 3, which has a through hole communicating with the second partition groove 113 to allow the second sealant to pass through, so as to facilitate the injection and filling of the second adhesive after the main housing 1 and the second side cover 3 are assembled and joined.

[0053] In the above embodiments, the pressure chip protective adhesive 404 and the circuit board protective adhesive 40 can be gels, such as silicone gels or fluorosilicone gels. The first sealant and the second sealant can be commonly used sealants, such as epoxy resin adhesives.

[0054] The scope of this disclosure is not limited by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be included in this disclosure.

Claims

1. A pressure sensing component, characterized in that, include: The circuit board (401) has pressure holes (408) that pass through both sides of the circuit board (401), and multiple electronic components are arranged on its front side; A pressure chip (402) is sealed on one side of the front of the circuit board (401) and connected to the pressure hole (408); A first side partition (61) and a second side partition (62) are fixed to the front of the circuit board (401) at intervals. A second partition groove (113) for accommodating a second partition rib (302) is formed between the first side partition (61) and the second side partition (62). The pressure chip (402) and the electronic components are separated by the second partition groove (113). The second partition groove (113) is filled with a second sealant. The pressure chip (402) is covered with pressure chip protective adhesive (404), and the electronic components are covered with circuit board protective adhesive (40). The first side partition (61) and / or the second side partition (62) are made of multiple layers of glue.

2. The pressure sensing component according to claim 1, characterized in that, The first side partition (61) and / or the second side partition (62) are integrally connected to the second side cover (3), and the second side cover (3) is provided with a through hole that connects to the second partition groove (113) to allow the second sealant to pass through.

3. The pressure sensing component according to claim 1, characterized in that, The multiple electronic components include a conditioning chip (406) and pads (407).

4. The pressure sensing component according to claim 1, characterized in that, The pressure chip protective adhesive (404) is surrounded by an adhesive frame (403), which is fixed to the circuit board (401).

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