A pressure sensor

Abstract

A pressure sensor comprises: a housing with an installation cavity formed inside, which has a pressure introduction channel communicated to the installation cavity at an inner end; an electronic module assembly arranged in the installation cavity, which has a substrate extending laterally and a processing circuit arranged on a front side of the substrate; a pressure sensitive element fixed to a back side of the substrate, which is electrically connected to an electrical connection part arranged on the back side of the substrate through a lead wire, and the electrical connection part is electrically connected to the processing circuit through the inside of the substrate; and a ring-shaped sealing gasket made of elastic material arranged on the back side of the substrate, which is tightly sealed to the inner end of the pressure introduction channel under the pressing force of the substrate towards the back side of the substrate, and the ring-shaped sealing gasket is filled with protective gel covering the pressure sensitive element and the lead wire. Compared with the prior art, the pressure sensor can reduce manufacturing cost and improve manufacturing efficiency.

Description

Technical Field

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

[0002] In existing pressure sensors, pressure-sensitive elements, such as pressure chips and their leads, need to be protected in a protective gel, which is contained within a frame. Typically, the frame needs to be bonded to the substrate surface with adhesive, followed by a lengthy curing process for the adhesive. This is detrimental to the sensor's cost and manufacturing efficiency. Summary of the Invention

[0003] In view of the shortcomings of the prior art, this application provides a pressure sensor to solve at least one of the above-mentioned defects.

[0004] The present invention provides a pressure sensor comprising: An outer shell that forms an internal mounting cavity has an inner end connected to the mounting cavity via a pressure inlet channel; An electronic module assembly disposed within the mounting cavity has a substrate that extends laterally with its back side facing one end of the pressure inlet channel and a processing circuit disposed on the front side of the substrate. A pressure-sensitive element fixed to one side of the back surface of the substrate is electrically connected to an electrical connection portion disposed on one side of the back surface of the substrate via a lead wire. The electrical connection portion is electrically connected to the processing circuit via the interior of the substrate. An annular sealing gasket made of elastic material is disposed on one side of the back of the substrate. The gasket is pressed and sealed to one end of the pressure inlet channel by the substrate under the action of the pressing force toward the back of the substrate. The annular sealing gasket is filled with a protective gel covering the pressure sensitive element and the lead wire.

[0005] Preferably, the annular sealing gasket is pre-fixed to one side of the back of the substrate.

[0006] Preferably, the annular sealing gasket has a connecting blind hole on one side of its back surface, and the annular sealing gasket has a connecting post protruding from one side of its front surface, the connecting post being tightly fitted into the connecting blind hole.

[0007] Preferably, the annular sealing gasket includes a sealing portion on the outer side and a gel receiving portion on the inner side that surrounds the pressure-sensitive element and the lead wire. The sealing portion is pressed and sealed to one end of the pressure introduction channel by the substrate on the back side. The gel receiving portion is filled with protective gel covering the pressure-sensitive element and the lead wire.

[0008] Preferably, the back ends of the sealing portion and the gel receiving portion are flush and integrally connected by a laterally extending thin plate-like connecting portion.

[0009] Preferably, the thin plate-shaped connecting part is hollow.

[0010] Preferably, the cross-section of the connecting column at least partially overlaps with the cross-section of the gel containment.

[0011] Preferably, the substrate has a longitudinally penetrating through-hole, the pressure-sensitive element is sealed at one end of the back side of the through-hole, and the front side of the through-hole is connected to the environment through the mounting cavity and the venting channel provided on the outer shell.

[0012] Preferably, a waterproof and breathable membrane is provided at one end of the inner side of the ventilation channel.

[0013] Preferably, the system further includes multiple terminals, and the substrate is provided with metal-plated holes. One end of each terminal extends into the mounting cavity for tight fitting and is electrically connected to the metal-plated holes.

[0014] This invention avoids adhesion between electronic module components and pressure introduction channels, while reducing manufacturing costs and improving manufacturing efficiency by placing protective gel in the sealing element. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view of a pressure sensor according to a preferred embodiment.

[0016] Figure 2 This is a partial three-dimensional view of the pressure sensor according to a preferred embodiment.

[0017] Explanation of reference numerals in the attached drawings: 1. Outer shell; 10. Mounting cavity; 100. Pressure sensor; 11. Main housing; 11a. Recess; 11b. Opening; 11c. Ventilation channel; 111. Hot riveting post; 12. Cover; 13. Electrical connection part; 131a. Terminal; 131b. Terminal; 1311. Fisheye-shaped connection part; 14. Pressure interface tube; 140. Pressure introduction channel; 2. Electronic module assembly; 20. Pressure sensitive element; 21. Substrate; 21a. Metal plating hole; 21b. Connection blind hole; 210. Through hole; 22. Processing circuit; 221. Processing chip; 23. Annular sealing gasket; 231. Sealing part; 232. Gel receiving part; 233. Thin plate-shaped connection part; 234. Connecting post; 24. Interior; 3. Waterproof and breathable membrane; 91. Sealing element; 93. Protective gel. Detailed Implementation

[0018] 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.

[0019] In the description of this application, it should be understood that the terms "upper," "lower," "inner," "outer," "left," and "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 of this application 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 do not indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the prepositions "first," "second," and "third," etc., are only used for the purpose of distinguishing the modified objects, and should not be construed as indicating or implying relative importance.

[0020] 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.

[0021] 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.

[0022] like Figure 1 , Figure 2 As shown, in a preferred embodiment of the present invention, the pressure sensor 100 may include a housing 1 and an electronic module assembly 2. The interior of the housing 1 forms a mounting cavity 10. Exemplarily, the housing 1 may include a main housing 11 and a cover 12 combined with the main housing 11. The upper end of the main housing 11 has a recess 11a with an upward-facing opening 11b, the recess 11a at least partially defining the mounting cavity 10. The cover 12 is bonded to and seals the opening 11b with a sealant 92, thereby forming the mounting cavity 10. Both the main housing 11 and the cover 12 may be made of resin material.

[0023] A pressure inlet channel 140 may be formed on the main housing 11. By way of example only, the pressure inlet channel 140 may be defined at least partially by the inner cavity of a pressure interface tube 14 integrally formed extending downward from the lower side of the main housing 11. The pressure interface tube 14 may be provided with a seal 91 for providing a seal when in fluid communication with a container of the medium to be measured.

[0024] One inner end of the pressure introduction channel 140 connects to the bottom of the mounting cavity 10. The electronic module assembly 2 is disposed at the bottom of the recess 11a and closes one inner end of the pressure introduction channel 140. For example, the electronic module assembly 2 includes a laterally extending substrate 21, and the back side of the substrate 21 (i.e., Figure 1 The upper side of the substrate 21 faces the inner end of the pressure introduction channel 140, and a processing circuit 22, including a processing chip 221, is provided on one side of the front side of the substrate 21.

[0025] The pressure sensor 100 also includes a pressure-sensitive element 20 and an annular sealing gasket 23. The pressure-sensitive element 20 is fixed to one side of the back surface of the substrate 21 and is electrically connected via leads to an electrical connection portion (not labeled) disposed on the back surface of the substrate 21. The electrical connection portion is electrically connected to the processing circuit 22 via the interior of the substrate 21.

[0026] An annular sealing gasket 23 is disposed on one side of the back side of the substrate 21 and is made of an elastic material. The annular sealing gasket 23 is pressed and sealed to one end of the pressure introduction channel 140 by the substrate 21 under the action of the pressing force toward the back side of the substrate 21. Moreover, the annular sealing gasket 23 is filled with a protective gel 93 covering the pressure sensitive element 20 and the lead wire.

[0027] The pressure sensor 100 of this embodiment uses an annular sealing gasket 23 as a receiving element for the protective gel, which avoids the drawback of the prior art where the sensor is bonded to the substrate 21 with a sealing adhesive, requiring a long period of time for the sealing adhesive to be applied, thereby reducing material costs and processing time. Preferably, the annular sealing gasket 23 is pre-fixed to the back side of the substrate 21, which facilitates the subsequent infusion of the protective gel 93. More preferably, the back side of the annular sealing gasket 23 may be provided with a connecting blind hole 21b, and the annular sealing gasket 23 may have a connecting post 234 protruding from the front side, the connecting post 234 being correspondingly and tightly fitted into the connecting blind hole 21b.

[0028] The annular sealing gasket 23 may include a sealing portion 231 and a gel receiving portion 232. The gel receiving portion 232 is located outside the sealing portion 231 and surrounds the pressure-sensitive element 20 and the lead wire within its interior 24. The sealing portion 231 is pressed and sealed to one end of the pressure introduction channel 140 by the substrate 21 on the back side. The gel receiving portion 232 is filled with protective gel 93 covering the pressure-sensitive element 20 and the lead wire. Preferably, the back ends of the sealing portion 231 and the gel receiving portion 232 are flush to facilitate contact with the lower surface of the substrate 21. They are preferably integrally connected by a laterally extending thin plate-like connecting portion 233, thereby reducing or avoiding additional stress interference to the protective gel 93 caused by longitudinal compression of the sealing portion 231 during assembly or operation, which would lead to longitudinal compression of the gel receiving portion 232. More preferably, the thin plate-like connecting portion 233 may be perforated, thereby forming a more flexible connection between the sealing portion 231 and the gel receiving portion 232.

[0029] Preferably, the cross-sections of the connecting post 234 and the gel receiving portion 232 at least partially overlap. For example, the cross-section of the connecting post 234 partially overlaps the cross-section of the gel receiving portion 232 inwardly, thus enabling the gel receiving portion 232 to maintain a relatively rigid connection with the substrate 21. Additionally, the radial thickness of the gel receiving portion 232 can be relatively increased or its longitudinal height reduced, thereby increasing the rigidity of the gel receiving portion 232 itself and reducing stress interference on the protective gel 93. By partially overlapping the cross-section of the connecting post 234 inwardly with the cross-section of the gel receiving portion 232, it also prevents the lead wire from detaching when the annular sealing gasket 23 is moved after being assembled to the substrate 21 and infused with the protective gel 93.

[0030] The substrate 21 may have a longitudinally penetrating through-hole 210. The pressure-sensitive element 20 is sealed at one end of the back side of the through-hole 210. The front end of the through-hole 210 is connected to the environment through the mounting cavity 10 and the venting channel 11c provided on the outer shell 1 to receive the ambient pressure as a reference pressure. In this case, the pressure-sensitive element 20 is a gauge pressure chip, and the pressure sensor 100 measures the relative pressure of the medium to be measured relative to the reference pressure, i.e., gauge pressure. A waterproof and breathable membrane 3 may be provided at one end of the venting channel 11c.

[0031] The pressure sensor 100 may further include multiple terminals 131a and 131b. A metal-plated hole 21a is provided on the substrate 21. A fisheye-shaped connecting portion 1311 formed at one end of each terminal 131a and 131b extends into the mounting cavity 10 and is tightly connected to and electrically connected to the metal-plated hole 21a, thereby providing at least partially the aforementioned clamping force. One outer end of the terminal 131a extends from an electrical connection portion 13 integrally connected to the main housing 11. At least one hot-riveting post 111 may also extend upwards within the cavity 11a, pressing the substrate 21 downwards, thereby also providing a portion of the clamping force.

[0032] In some other embodiments, the pressure-sensitive element 20 described above may also be an absolute pressure chip, and the mounting cavity 10 may also be completely isolated from the environment, that is, the above-mentioned air-permeable channel 11c and waterproof and breathable membrane 3 may be omitted accordingly.

[0033] 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 sensor (100), characterized by include: The outer shell (1) forms an inner mounting cavity (10) and has a pressure introduction channel (140) with one end connected to the mounting cavity (10); The electronic module assembly (2) disposed in the mounting cavity (10) has a substrate (21) extending laterally with its back side facing the inner end of the pressure introduction channel (140) and a processing circuit (22) disposed on the front side of the substrate (21). A pressure-sensitive element (20) fixed to one side of the back surface of the substrate (21) is electrically connected to an electrical connection part provided on one side of the back surface of the substrate (21) via a lead wire. The electrical connection part is electrically connected to the processing circuit (22) via the interior of the substrate (21). An annular sealing gasket (23) made of elastic material is disposed on one side of the back of the substrate (21), which is pressed and sealed to one end of the pressure introduction channel (140) by the substrate (21) under the action of the pressing force towards the back of the substrate (21), and the annular sealing gasket (23) is filled with a protective gel (93) covering the pressure sensitive element (20) and the lead wire.

2. The pressure sensor (100) according to claim 1, characterized in that The annular sealing gasket (23) is pre-fixed to one side of the back of the substrate (21).

3. The pressure sensor (100) according to claim 2, characterized in that The annular sealing gasket (23) has a connecting blind hole (21b) on one side of its back side, and the annular sealing gasket (23) has a connecting post (234) protruding from one side of its front side, and the connecting post (234) is correspondingly and tightly fitted into the connecting blind hole (21b).

4. The pressure sensor (100) according to claim 3, characterized in that The annular sealing gasket (23) includes an outer sealing portion (231) and an inner gel receiving portion (232) surrounding the pressure-sensitive element (20) and the lead wire. The sealing portion (231) is pressed and sealed to the inner end of the pressure introduction channel (140) by the substrate (21) on the back side. The gel receiving portion (232) is filled with a protective gel (93) covering the pressure-sensitive element (20) and the lead wire.

5. The pressure sensor (100) according to claim 4, characterized in that The sealing part (231) and the gel receiving part (232) are flush at one end on their back sides and are integrally connected by a laterally extending thin plate-shaped connecting part (233).

6. The pressure sensor (100) according to claim 5, characterized in that The thin plate-shaped connecting part (233) is hollow.

7. The pressure sensor (100) according to claim 4, characterized in that The cross-section of the connecting post (234) at least partially overlaps with that of the gel receiving portion (232).

8. The pressure sensor (100) according to any one of claims 1 to 7, characterized in that The substrate (21) is provided with a longitudinal through hole (210), the pressure sensitive element (20) is sealed at one end of the back side of the through hole (210), and the front side of the through hole (210) is connected to the environment through the mounting cavity (10) and the venting channel (11c) provided on the outer shell (1).

9. The pressure sensor (100) according to claim 8, characterized in that A waterproof and breathable membrane (3) is provided at one end of the inner side of the ventilation channel (11c).

10. The pressure sensor (100) according to claim 8, characterized in that It also includes multiple terminals (131a), and the substrate (21) is provided with metal-plated holes (21a). One end of the terminal (131a) extends into the mounting cavity (10) for tight fitting and is electrically connected to the metal-plated holes (21a).

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