Pressure measuring assembly and gauge pressure sensor

Abstract

A pressure measurement assembly with high measurement precision comprises a horizontally arranged substrate, the upper side surface of which is provided with a processing circuit; the pressure sensitive element is hermetically fixed at the upper end of a pressure via hole formed in the substrate and is electrically connected to the processing circuit; the enclosure frame is fixed on the upper side surface of the substrate and comprises a circle of enclosure wall which is vertically arranged and surrounds the pressure sensitive element, at least one pipe body which is vertically arranged and a cover plate which seals the upper end of the enclosure wall and the upper end of the pipe body, one end of the pipe body is communicated with an inner cavity of the enclosure wall, and the other end of the pipe body downwards crosses the upper side surface of the substrate; and the inner cavity of the enclosure frame is filled with the protective gel. The invention further discloses a gauge pressure sensor which comprises the pressure measuring assembly. The shell is provided with a pressure introduction channel which is inwards communicated to the mounting cavity and an air duct which introduces environment reference pressure into the pipe body, and the lower side surface of the base plate is fixedly plugged at one end of the inner side of the pressure introduction channel; a waterproof breathable film covers the inner side of the ventilation channel.

Description

Technical Field

[0001] This application relates to the technical field of pressure sensors, and particularly relates to a pressure measurement component and a gauge pressure sensor. Background Art

[0002] Existing pressure sensors generally use pressure-sensitive elements such as pressure chips to measure pressure. These pressure-sensitive elements are connected to the circuit through leads. To protect the pressure-sensitive elements and leads, a gel needs to be covered on the pressure chip and the leads, and the gel is shaped by a surrounding frame. However, the gel itself has a certain weight, and the weight applied to the pressure-sensitive element will cause errors, especially under working conditions with large accelerations such as vibration, where the errors will be even greater. When measuring gauge pressure, the gel is also used to transfer the ambient reference pressure to the pressure-sensitive element.

[0003] The information disclosed in the background part of the present invention is only used to enhance the understanding of the general background of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0004] In view of the deficiencies of the prior art, this application provides a pressure measurement component and a gauge pressure sensor to reduce the adverse effects of the protective gel on pressure measurement.

[0005] To achieve the above object, this application provides the following technical solution: A pressure measurement component, which includes:

[0006] A horizontally arranged substrate, on the upper side surface of which a processing circuit is provided;

[0007] A pressure-sensitive element hermetically fixed at the upper end of a pressure through-hole provided on the substrate, and electrically connected to the processing circuit;

[0008] A surrounding frame fixed on the upper side surface of the substrate, including a surrounding wall vertically arranged and surrounding the pressure-sensitive element, at least one vertically arranged tube body, and a cover plate closing the upper ends of the surrounding wall and the tube body, one end of the tube body communicating with the inner cavity of the surrounding wall and the other end extending downward beyond the upper side surface of the substrate;

[0009] A protective gel filled in the inner cavity of the surrounding frame.

[0010] Preferably, a bonding surface is formed at the lower end of the surrounding wall, and the bonding surface is bonded to the upper side surface of the substrate through an adhesive.

[0011] Preferably, the upper end of the tube body is located outside the surrounding wall, and the upper end of the tube body is communicated with the inner cavity of the surrounding wall through a lateral channel.

[0012] Preferably, the surrounding frame further includes a connecting portion integrally connected to the surrounding frame and the tube body, and the lateral channel is defined by a connecting portion.

[0013] Preferably, the tube body extends over the upper surface of the substrate from the outside of the substrate.

[0014] Preferably, the lower end of the tube body faces and extends into a through hole provided in the substrate.

[0015] Preferably, the upper end of the tube body is at least partially upwardly and directly communicated with the inner cavity of the surrounding frame, and at least a part of the corresponding side wall upper end is substantially flush with the upper surface of the substrate.

[0016] Preferably, the protective gel is lower than or substantially flush with the upper surface of the substrate.

[0017] The present invention also claims protection for a gauge pressure sensor, which includes:

[0018] The above pressure measurement assembly;

[0019] And a housing forming an installation cavity for receiving the pressure measurement assembly, which has a pressure introduction channel communicating inwardly with the installation cavity and a ventilation channel for introducing ambient reference pressure into the tube body. The lower surface of the substrate is fixedly sealed at the inner end of the pressure introduction channel; the inner side of the ventilation channel is covered with a waterproof and breathable membrane.

[0020] In the above gauge pressure sensor, preferably, the installation cavity has a ventilation cavity located below the substrate, the tube body communicates with the ventilation cavity, and the inner end of the ventilation channel communicates with the ventilation cavity.

[0021] The present invention can adsorb the protective gel filled therein through the surrounding frame with a cover plate, thereby reducing the self-gravity of the protective gel applied to the pressure-sensitive element, and thus reducing the measurement error caused by the self-gravity of the protective gel. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the gauge pressure sensor of the first embodiment.

[0023] Figure 2 It is a schematic structural diagram of the pressure measurement assembly of the first embodiment.

[0024] Figure 3 It is a perspective view of the surrounding frame of the first embodiment.

[0025] Figure 4 It is a perspective view of the surrounding frame of the second embodiment.

[0026] Figure 5Schematic structural diagram of the pressure measurement component of the third embodiment. Detailed implementation manners

[0027] The technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and cannot be construed as a limitation to the present application. In the following description, the same reference numerals are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0028] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is normally placed, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present application. In addition, the prefixes "first", "second", "third", etc. are only used for the purpose of distinguishing the modified objects, and cannot be construed as indicating or implying relative importance.

[0029] In addition, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0030] It should be further understood that the term "and / or" used in the specification and corresponding claims of the present application refers to any combination of one or more of the listed items and all possible combinations.

[0031] Please refer to Figures 1 to 3. In the first embodiment, the pressure measurement assembly 2 includes a substrate 22, a pressure sensitive element 23, and a surrounding frame 21. Among them, the substrate 22 is horizontally arranged, and a processing circuit 220 is arranged on its upper side surface. The pressure sensitive element 23 is hermetically fixed to the upper end of a pressure through hole 22a arranged on the substrate 22. The surrounding frame 21 is fixed to the upper side surface of the substrate 22, and it includes a surrounding wall 211, a cover plate 213, and a tube body 212. Among them, the surrounding wall 211 is vertically arranged and forms a circle, and the surrounding wall 211 surrounds the pressure sensitive element 23. The cover plate 213 closes the upper end of the surrounding wall 211 and the upper end of the tube body 212. One end of the tube body 212 communicates with the inner cavity of the surrounding wall 211, and the other end thereof faces downward and extends beyond the upper side surface of the substrate 22. The inner cavity 20a of the surrounding frame 21 is filled with a protective gel 20. Among them, the pressure sensitive element 23 can be electrically connected to the processing circuit 220 through a lead 23a, and the lead 23a can be located inside the surrounding wall 211 and is also covered by the above-mentioned protective gel 20. The tube body 212 is vertically arranged, and the other end thereof has an opening 212b.

[0032] When filling the protective gel 20 into the inner cavity 20a of the surrounding frame 21, the surrounding frame 21 can be first fixed to the substrate 22, and then they are inverted as a whole and the protective gel 20 is filled from the opening 212b.

[0033] For the above-mentioned pressure measurement assembly 2, by arranging the cover plate 213 at the upper end of the surrounding frame 21, the top of the protective gel 20 can be adsorbed on the lower side surface of the cover plate 213, thereby reducing the additional pressure of the weight of the protective gel 20 on the pressure sensitive element 23. Among them, a small hole 213a can be provided on the cover plate 213 to facilitate the discharge of air when filling the protective gel 20. The small hole 213a preferably does not overlap with the projection of the pressure sensitive element 23 on the horizontal plane, that is, the small hole 213a is preferably offset from the pressure sensitive element 23 in the horizontal direction.

[0034] Preferably, the upper end of the tube body 212 is located outside the surrounding wall 211, and the upper end of the tube body 212 communicates with the inner cavity of the surrounding wall 211 through a lateral channel 21a. Among them, the lateral channel 21a is defined by a connecting portion 214, and the connecting portion 214 can be integrally connected between the surrounding frame 21 and the tube body 212. The lower end of the tube body 212 can extend downward into a through hole 22b arranged on the substrate 22.

[0035] Among them, a bonding surface 211a can be formed at the lower end of the surrounding wall 211, and the bonding surface 211a is bonded to the upper side surface of the substrate 22 through an adhesive 2119. In some other solutions, the surrounding frame 21 can also be fixed to the substrate 22 by a buckle, or the tube body 212 can be tightly fitted into the through hole 22b, and two or more tube bodies 212 can also be provided.

[0036] The gauge pressure sensor 100 of this embodiment, in addition to including the above-mentioned pressure measurement component 2, further includes a housing 1. An installation cavity 10 for accommodating the pressure measurement component 2 is formed inside the housing 1, which may have a pressure introduction channel 110 communicating inwardly with the installation cavity 10 and a ventilation channel 11a for introducing ambient reference pressure into the tube body 212. Among them, the pressure introduction channel 110 may be defined by the inner cavity of a pressure interface 111 formed on the main housing 11. An electrical plug portion 112 may also be formed on the main housing 11. One end of a plurality of terminals 4 passes through the electrical plug portion 112 inwardly and is electrically connected to a pad 220a formed on the processing circuit 220 through a lead 5. A seal 14 may be sleeved outside the pressure interface 111.

[0037] Merely by way of example, the housing 1 may include a main housing 11 and an upper cover 12. A concave cavity (not marked) is formed at the upper end of the main housing 11, and the upper cover 12 is covered on the concave cavity to enclose the above-mentioned installation cavity 10 with the main housing 11. The lower side surface of the substrate 22 of the pressure measurement component 2 may be bonded to a bonding surface 11c formed on the main housing 11, so as to fixedly block the inner end of the pressure introduction channel 110, so that the pressure sensitive element 23 obtains the pressure of the pressure medium to be measured introduced by the pressure introduction channel 110 through the pressure through hole 22a on the substrate 22, and prevents the medium to be measured from leaking into the installation cavity 10. Among them, the inner side of the ventilation channel 11a is preferably covered with a waterproof and breathable membrane 3.

[0038] Preferably, the installation cavity 10 may have a ventilation cavity 11b located below the substrate 22. The tube body 212 communicates with the ventilation cavity 11b, and the inner end of the ventilation channel 11a communicates with the ventilation cavity 11b.

[0039] Please refer to Figure 4 . On the basis of the first embodiment, the pressure measurement component 2 of the second embodiment may include two tube bodies 212. Different from the first embodiment, the two tube bodies 212 respectively cross over the upper side surface of the substrate 22 from the outside of the substrate 22.

[0040] Please refer to Figure 5 . On the basis of the first embodiment, in the third embodiment, at least a part of the upper end of the tube body 212 is directly connected upward to the inner cavity of the surrounding frame 21, that is, the horizontal projection of a part of the inner wall of the tube body 212 at least partially coincides with the horizontal projection of the surrounding wall 211.

[0041] Preferably, the tube body 212 may cross over the upper side surface of the substrate 22 from the outside of the substrate 22, rather than extending into the through hole 22b provided on the substrate 22. At this time, the surrounding frame 21 may be fixed to the surrounding wall 211 by a buckle, and the buckle may be buckled downward on the edges of the two opposite sides of the substrate 22 along the width direction.

[0042] The upper end 212c of the side wall corresponding to at least a part of the inner cavity of the enclosure 21, to which the upper part of the tube body 212 is communicatively connected facing upward, is at least partially flush with the upper surface of the substrate 22. In the inner cavity 212a of the tube body 212, the free surface 20b of the protective gel 20 and the upper surface of the substrate 22 are preferably lower than or substantially flush with the upper surface of the pressure-sensitive element 23, so that the additional gravity applied to the pressure-sensitive element 23 by the protective gel 20 can be balanced to a certain extent. When the pressure-sensitive element 23 is a pressure chip, or when the height of the pressure-sensitive element 23 is small, the free surface 20b of the protective gel 20 and the upper surface of the substrate 22 can also be roughly lower than or substantially flush with the upper surface of the substrate 22.

[0043] The scope of the present disclosure is not limited by the detailed description, but is defined by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are construed as being included in the present disclosure.

Claims

1. A pressure measurement assembly (2), characterized in that: include: A horizontally arranged substrate (22) having a processing circuit (220) arranged on its upper surface; A pressure sensitive element (23) sealed and fixed to the upper end of a pressure through hole (22a) provided on the substrate (22), and electrically connected to the processing circuit (220); A surrounding frame (21) fixed to the upper surface of the substrate (22), comprising a circle of surrounding walls (211) arranged vertically and surrounding the pressure sensitive element (23), at least one vertically arranged tube (212), and a cover plate (213) closing the upper ends of the surrounding walls (211) and the tube (212), one end of the tube (212) being in communication with the inner cavity of the surrounding walls (211) and the other end of the tube (212) being downwardly passed over the upper surface of the substrate (22); A protective gel (20) is filled in the inner cavity of the surrounding frame (21).

2. The pressure measuring assembly (2) according to claim 1, characterized in that A circle of bonding surface (211a) is formed at the lower end of the surrounding wall (211), and the bonding surface (211a) is bonded to the upper surface of the substrate (22) by an adhesive (2119).

3. The pressure measuring assembly (2) according to claim 2, characterized in that The upper end of the tube body (212) is located outside the surrounding wall (211), and the upper end of the tube body (212) is connected to the inner cavity of the surrounding wall (211) through a lateral channel (21a).

4. The pressure measurement assembly (2) according to claim 3, characterized in that: The surrounding frame (21) further comprises a connecting portion (214) integrally connected to the surrounding frame (21) and the tube body (212), and the lateral channel (21a) is defined by the connecting portion (214).

5. The pressure measurement assembly (2) according to claim 2, characterized in that: The tube body (212) passes over the upper surface of the substrate (22) from the outside of the substrate (22).

6. The pressure measurement assembly (2) according to claim 2, characterized in that: The lower end of the tube body (212) extends toward and into a through hole (22b) provided on the base plate (22).

7. The pressure measurement assembly (2) according to any one of claims 1 to 6, characterized in that: The upper end of the tube body (212) is at least partially connected to the inner cavity of the surrounding frame (21) facing upward, and the corresponding side wall upper end (212c) is at least partially substantially flush with the upper surface of the base plate (22).

8. The pressure measuring assembly (2) according to any one of claims 1 to 6, characterized in that The protective gel (20) and the upper surface of the substrate (22) are lower than or substantially flush with the upper surface of the substrate (22).

9. A gauge pressure sensor (100), characterized in that: include: The pressure measuring assembly (2) according to any one of claims 1 to 8; A housing (1) is formed to house a mounting cavity (10) for accommodating the pressure measuring component (2), and has a pressure introduction channel (110) inwardly connected to the mounting cavity (10) and an air duct (11a) for introducing an environmental reference pressure into the tube body (212); the lower surface of the substrate (22) is fixedly sealed to an inner end of the pressure introduction channel (110); the inner side of the air duct (11a) is covered with a waterproof and breathable membrane (3).

10. The gauge pressure sensor (100) according to claim 9, characterized in that: The installation cavity (10) has a ventilation cavity (11b) located at the lower side of the substrate (22); the tube body (212) is connected to the ventilation cavity (11b); and an inner end of the ventilation channel (11a) is connected to the ventilation cavity (11b).

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