Pressure sensor

Abstract

A pressure sensor with a simple structure and an optimized size comprises a main housing which is provided with a pressure introduction channel; one end of the pressure introduction channel is used for introducing a to-be-measured pressure medium, and the second end of the pressure introduction channel penetrates to a mounting plane on one side surface of the main shell; the pressure measuring assembly is mounted on the mounting plane and is provided with a pressure sensitive element which is plugged and coupled to the other end of the pressure introduction channel; the plurality of electrical connection terminals are fixed on the main shell, and one end of each electrical connection terminal is electrically connected to the pressure measuring assembly; and the connecting structure is formed by outwards extending one side of the mounting plane of the main shell and is mechanically connected with external equipment.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a pressure sensor. Background Art

[0002] Pressure sensors are used to measure the pressure of the pressure medium to be measured. According to the different measured pressures, they can be divided into three types: absolute pressure, differential pressure and gauge pressure. When measuring gauge pressure, a vent is required to obtain the environmental reference pressure. Existing gauge pressures usually have a closed shell to protect the pressure measurement components (especially the pressure chip) in its inner cavity from the erosion of moisture in the environment. It needs to obtain the reference pressure through a vent covered by a waterproof and breathable membrane, while isolating external moisture. Since the shell of this type of pressure sensor needs to be closed, considering the manufacturability, it usually includes a main shell and at least one cover combined together, and the electrical connection terminals arranged on the main shell or on the cover (the cover can also be called a terminal) are electrically connected to the pressure measurement component. However, in some application environments (such as a relatively dry environment or an environment with a protective shell on the outside), the cover may not be necessary. This makes it possible to simplify the structure and optimize the size of such pressure sensors.

[0003] On the other hand, in order to protect the relatively fragile pressure chip and the leads for connecting to the measuring circuit, a frame is usually used to surround the pressure chip and the leads, and a protective gel is filled in the frame to protect them from mechanical and chemical adverse factors. When considering omitting the cover to simplify the structure of the above-mentioned pressure sensor, in order to simultaneously protect the pressure chip and the leads through the protective gel, such a difficulty is introduced, that is, the pressure chip and the leads still need to be isolated from external moisture. If they are separated from the external environment by a frame with vents, it is necessary to cover the vents with a waterproof breathable film. The protective gel needs to be vented under vacuum to discharge the bubbles in the gel. Since the viscosity of the gel is usually large, it is difficult to completely discharge the bubbles. When using such a frame, we found that due to the limitations of the allowable size of the sensor, the area of ​​the circuit board, and the edge bonding width of the waterproof breathable film, the available size of the vent is not enough to ensure smooth exhaust, resulting in sensor measurement errors or requiring several times of time to achieve complete exhaust. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present application provides a pressure sensor to solve at least one of the above technical defects.

[0005] To achieve the above objectives, the present application provides the following technical solution: a pressure sensor, comprising:

[0006] The main housing has a pressure introduction channel; one end of the pressure introduction channel is used to introduce the pressure medium to be measured, and the second end thereof penetrates to a mounting plane on a side surface of the main housing;

[0007] A pressure measurement assembly mounted on the mounting plane, which has a pressure sensitive element that is blocked and coupled to the other end of the pressure introduction channel;

[0008] a plurality of electrical connection terminals fixed to the main housing, one end of which is electrically connected to the pressure measurement assembly;

[0009] And a connection structure for mechanical connection with external equipment is formed by extending outward from one side of the installation plane of the main shell.

[0010] Preferably, the pressure introduction channel includes a first portion extending longitudinally, and a second portion extending transversely from an inner end of the first portion to penetrate to the mounting plane, and the pressure measuring component is generally arranged longitudinally.

[0011] Preferably, the mounting plane is arranged at the bottom of a recessed portion formed by the one side surface of the main shell being recessed inwardly.

[0012] Preferably, one end of the electrical connection terminal is electrically connected to the pressure measurement component, and the other end of the electrical connection terminal generally extends longitudinally toward a side away from the pressure measurement component.

[0013] Preferably, the connection structure includes a plurality of buckles extending laterally from one side of the main housing where the pressure measuring assembly is disposed.

[0014] Preferably, the pressure measurement component includes a substrate adhered and fixed on the mounting plane; a processing circuit including a plurality of electronic components is arranged on a side of the substrate away from the mounting plane; the processing circuit is electrically connected to the one end of the electrical connection terminal; the pressure sensitive element is fixed on a side of the substrate away from the mounting plane and is electrically connected to the processing circuit through a lead.

[0015] Preferably, the electrical connection terminal comprises a transverse portion and a longitudinal portion which are integrally connected, the transverse portion is electrically connected to the processing circuit, and a middle portion of the longitudinal portion forms an elastic portion having elasticity in the longitudinal direction.

[0016] Preferably, the elastic portion is U-shaped, and two ends of the elastic portion are respectively connected integrally and vertically to two adjacent ends of other parts of the electrical connection terminal.

[0017] Preferably, a protective gel covering at least the pressure sensitive element and the lead is fixedly disposed on a side of the substrate away from the mounting plane.

[0018] Preferably, the protective gel is contained in a frame assembly fixed to a corresponding side of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional diagram of the pressure sensor of the first embodiment;

[0020] Figure 2 is a top view of the pressure sensor of the first embodiment;

[0021] Figure 3 The pressure sensor of the first embodiment is Figure 2 A cross-sectional view of AA shown in FIG.

[0022] Figure 4 for Figure 3 An enlarged view of the part B shown in FIG.

[0023] Figure 5 It is a structural schematic diagram of the pressure measurement assembly of the second embodiment;

[0024] Figure 6 FIG. 4 is a schematic structural diagram of a pressure measurement assembly according to a third embodiment.

[0025] Description of reference numerals: 11a, first part; 11b, second part; 11, pressure introduction channel; 12, interface tube; 13, positioning structure; 14, mounting plane; 15, recessed part; 1, main shell; 20, pressure sensitive element; 21a, pressure through hole; 21b, conductive hole; 21, substrate; 23, electronic component; 24, lead wire; 2, pressure measurement component; 31a, cantilever part; 31b, connecting part; 31c, buckle part; 31, first buckle; 32, second buckle; 3, connecting structure; 4, waterproof permeable air film; 5, protective gel; 61, transverse part; 62, longitudinal part; 63, elastic part; 6, electrical connection terminal; 250, third adhesive; 251a, body; 251b, second extension; 251c, cover; 251d, vent; 251, second frame; 252a, body; 252b, first extension; 252c, support; 252d, groove; 252e, inner wall of groove; 252f, opening; 252g, third extension; 252, first frame; 25, frame assembly; DETAILED DESCRIPTION

[0026] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application. In the following description, the same symbols are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0027] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present application are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do 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 should not be understood as a limitation on the present application.

[0028] In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] It should be further understood that the term “and / or” used in the specification and corresponding claims of this application refers to any and all possible combinations of one or more of the listed items.

[0030] Please refer to Figure 1 to Figure 3 In the first embodiment, the pressure sensor comprises a main housing 1 extending substantially longitudinally, the main housing 1 having a substantially longitudinal ( Figure 3 The pressure introduction channel 11 extends in the left and right directions. One longitudinal end of the pressure introduction channel 11 is used to introduce the pressure medium to be measured, and the second longitudinal end thereof penetrates to one side of the main housing 1 ( Figure 3 The pressure sensor further comprises a pressure measuring assembly 2 mounted on the mounting plane 14, the pressure measuring assembly 2 having a pressure sensitive element 20 corresponding to the plug and coupled to the other end of the pressure introduction channel 11. The main housing 1 can be made of a resin material, and a plurality of electrical connection terminals 6 can be molded and fixed thereon. These electrical connection terminals 6 are preferably arranged along Figure 3 One end of the electrical connection terminal 6 is electrically connected to the pressure measurement component 2, and the other end thereof can generally extend longitudinally toward a side away from the pressure measurement component 2 to the outside of the main housing 1 for electrical connection with an external device.

[0031] The mounting plane 14 of the main housing 1 extends outwardly to form a connection structure 3 for mechanical connection with an external device. For example, the connection structure may include a first buckle 31 and a second buckle 32 extending outwardly from the side of the main housing 1 where the pressure measuring assembly 2 is provided. These buckles can be connected to a plate-shaped or other shaped external device. Figure 1 In order to make the buckle 31 have a certain elasticity in the transverse direction, the first buckle 31 can include a buckle portion 31c, the lower end of the buckle portion 31c extends longitudinally to form a cantilever portion 31a, and the end of the cantilever portion 31a away from the buckle portion 31c is connected to the corresponding front and rear sides of the main housing 1 through the connecting portion 31b. In this way, Figure 1 The "U"-shaped structure composed of the connecting portion 31b, the cantilever portion 31a and the buckle portion 31c shown in the figure can make the first buckle 31 have a certain elasticity in the up and down direction, so as to facilitate the mechanical connection between the first buckle 31 and the external device. Similarly, the second buckle 32 can also adopt a structure similar to the first buckle 31.

[0032] The pressure measuring assembly 2 may also be arranged substantially in the longitudinal direction. The lower portion of the main housing 1 may extend outward in the longitudinal direction toward an end away from the electrical connection terminal 6 to form an interface tube 12, and the first portion 11a may be defined by the inner cavity of the interface tube 12. A stepped positioning structure 13 may be provided at one end of the outer side of the interface tube 12 to facilitate positioning when connected to a fluid interface of a container or pipeline containing a pressure medium to be measured.

[0033] The pressure sensor of this embodiment omits the cover which is usually provided in the pressure sensor of the prior art, so the structure is simplified; Figure 3 The pressure sensors are particularly suitable for use in enclosed or semi-enclosed spaces with certain protection such as automobiles, or in other less harsh environments.

[0034] In some other solutions, there may be more than one pressure introduction channel 11 and corresponding pressure sensitive element 20. For example, two pressure sensitive elements 20 and two pressure introduction channels 11, or more, may be provided.

[0035] Specifically, the pressure introduction channel 11 may include a first portion 11a extending longitudinally, and a second portion 11b extending transversely, wherein the second portion 11b is formed by extending the inner end of the first portion 11a in the transverse direction, and the end of the second portion 11b away from the first portion 11a (i.e. Figure 3 The upper end of the main housing 1 is connected to the mounting plane 14. Preferably, in order to further reduce the vertical dimension of the pressure sensor, the mounting plane 14 can be arranged at the bottom of a recessed portion 15 formed by the inward recess of the upper surface of the main housing 1.

[0036] Specifically, the pressure measurement assembly 2 may include a substrate 21 fixedly attached to the mounting plane 14, at least one pressure sensitive element 20 disposed on the upper side of the substrate 21, and a measurement circuit electrically connected to the pressure sensitive element 20 through a lead 24. The substrate 21 is provided with at least one pressure through hole 21a penetrating through both sides of the substrate 21. The pressure sensitive element 20 is correspondingly blocked on one side of the pressure through hole 21a. The side of the substrate 21 away from the mounting plane 14 (i.e. Figure 3 A processing circuit (not marked) including a plurality of electronic components 23 is provided. The processing circuit is electrically connected to an end of the electrical connection terminal 6 close to the pressure measurement component 2. For example, the corresponding end of the electrical connection terminal 6 may extend upward to form a transverse portion 61 perpendicular to the substrate 21. A conductive hole 21b may be provided on the substrate 21. The transverse portion 61 may be welded to the conductive hole 21b. The conductive hole 21b is electrically connected to the processing circuit on the upper side of the substrate 21. The pressure sensitive element 20 is fixed to a side of the substrate 21 away from the mounting plane 14 (i.e. Figure 3 ) and is electrically connected to the processing circuit via lead 24.

[0037] Preferably, in order to fix the pressure sensor to the external device while enabling the electrical connection terminal 6 to be easily plugged in, the electrical connection terminal 6 may include the above-mentioned transverse portion 61 and a longitudinal portion 62 which are integrally connected, and the middle portion of the above-mentioned longitudinal portion 62 forms an elastic portion 63 which is elastic in the longitudinal direction. For example, the elastic portion 63 may be U-shaped, and the two ends of the elastic portion 63 are respectively integrally and vertically connected to the adjacent two ends of other parts of the electrical connection terminal 6, and the elastic portion 63 may be formed by the longitudinal portion 62 arching toward the transverse direction.

[0038] Preferably, the pressure measurement assembly 2 may further include at least one frame assembly 25 arranged corresponding to the pressure sensitive element 20. A protective gel 5 covering at least the pressure sensitive element 20 and the lead 24 is fixedly arranged on one side of the substrate 21 away from the mounting plane 14. The protective gel 5 may be accommodated in a corresponding frame assembly 25 fixed to a corresponding side of the substrate 21.

[0039] The frame assembly 25 may include at least one first frame 252 corresponding to the pressure sensitive element 20 , with an opening 252 f at the upper end thereof and a protective gel 5 filled therein.

[0040] Preferably, the frame assembly 25 may further include at least one second frame 251 and at least one waterproof breathable membrane 4. The second frame 251 is assembled and fixed to the corresponding first frame 252. The second frame 251 has a cover 251c covering the opening 252f. The cover 251c is provided with a vent 251d for penetrating the upper and lower sides of the cover 251c. The waterproof breathable membrane 4 is bonded to a substantially flat mounting surface provided on the inner side of the cover 251c, thereby covering the upper end of the vent 251d; in some other schemes, the waterproof breathable membrane 4 may also be provided on the lower surface of the cover 251c by other means, thereby covering the lower end of the vent 251d.

[0041] Please refer to Figure 4 Preferably, the lower end of the first frame 252 extends outward along a plane to form a circle of first extension parts 252b, and the first extension parts 252b can be more firmly and tightly bonded to the upper surface of the substrate 21 by a first adhesive (not shown). More preferably, the lower end of the second frame 251 also extends outward along a plane to form a circle of second extension parts 251b, and the second extension parts 251b can be tightly bonded to the upper surface of the first extension parts 252b by a second adhesive (not shown).

[0042] See also Figure 5 . In the second embodiment, preferably, the upper end of the first frame 252 may form a third extension portion 252g extending substantially up and down. The third extension portion 252g is integrally connected to the body 252a of the first frame 252 through a circle of support portions 252c. The body 251a of the second frame 251 may extend up and down, and the lower end of the body 251a may be supported against the middle of the support portion 252c. The gap between the body 251a, the third extension portion 252g and the groove 252d is filled with the third adhesive 250, so that the body 251a of the first frame 251 may be sealed and bonded to the third extension portion 252g by the third adhesive 250. In some other schemes, the lower end of the body 251a of the first frame 251 may also extend outwardly with respect to the upper end, for example, it may be a conical cylinder with the cone top facing upward. The lower end of the body 251a can be supported against the outer edge of the support portion 252c, or tightly fit on the inner wall of the third extension portion 252g. Preferably, it is best to make the protective gel 5 lower than the upper edge of the body 252a, so that when the lower end of the body 251a is tightly fitted on the inner wall of the third extension portion 252g, the body 252a and the third extension portion 252g are integrally connected through the support portion 252c, so that the installation stress generated by the tight fit or threaded fit is transmitted to the protective gel 5 filled in the body 252a, which can reduce the measurement error caused by the transmission.

[0043] Preferably, the support portion 252c may be recessed downward to form a circle of grooves 252d. The inner peripheral wall of the body 251a may be supported on the inner wall 252e of the groove 252d. A part or all of the third adhesive 250 is accommodated in the groove 252d. This can reduce the risk of the third adhesive 250 overflowing into the inner cavity of the first frame 251, and can further reduce the transmission of the installation stress to the body 252a.

[0044] See also Figure 6 In the third embodiment, the upper portion of the body 252a of the second frame 251 extends up and down, and can be tightly fitted or threadedly fitted to the inner wall of the third extension portion 252g. After the upper portion of the body 252a shrinks inward, a gap is formed between the body 252a and the third extension portion 252g for accommodating at least a portion of the third adhesive 250. The lower end of the body 251a of the second frame 251 is supported downward on the support portion 252c, specifically, can be supported on the bottom of the groove 252d.

[0045] In the above embodiments, the first frame 252 is preferably a metal part, and the first frame 252 can additionally form an electromagnetic shield for the pressure sensitive element 20 and the lead 24; preferably, the second frame 251 can also be a metal part, so that the first frame 252 can form an electrical contact by supporting the second frame 251, so that the frame assembly 25 can additionally form a complete electromagnetic shield for the pressure sensitive element 20 and the lead 24. In the first embodiment, the second frame 251 can be a metal part, and the first frame 252 can be a metal part or not, so that a complete electromagnetic shield can also be formed. The lower end of the body 251a of the second frame 251 can be tilted outward relative to the upper end, so that the additional pressure loaded on the pressure sensitive element by the weight of the protective gel 5 itself and the pressure fluctuations that may be caused by vibration can be relatively reduced.

[0046] Preferably, the first frame body 252 and / or the second frame body 251 are thin shell-shaped elements obtained by stamping.

[0047] Preferably, in order to further ensure reliable electrical contact between the first frame 252 and the second frame 251, the third adhesive 250 may be a conductive adhesive. Similarly, the second adhesive may also be a conductive adhesive. More preferably, the first adhesive may also be a conductive adhesive, in which case the first frame 252 may be electrically connected to a ground terminal of the measurement circuit through the conductive adhesive.

[0048] The present application also provides a method for manufacturing a pressure measurement assembly 2, which comprises:

[0049] A substrate 21 is provided, on the upper side of which at least one pressure sensitive element 20 and a measuring circuit electrically connected to the pressure sensitive element 20 through a lead 24 are arranged, and at least one pressure through hole 21a is arranged on the substrate 21 and passes through both sides of the substrate 21. The pressure sensitive element 20 is correspondingly blocked on the upper side of the pressure through hole 21a;

[0050] Provide at least one first frame 252 having an opening 252f at the upper end, seal the lower end of the first frame 252 to the upper side of the substrate 21 by a first adhesive, and surround the pressure sensitive element 20 inside the first frame 252;

[0051] Filling the first frame 252 with a protective gel 5 so that the protective gel 5 at least covers the corresponding pressure sensitive element 20 and the lead 24;

[0052] Exhausting the protective gel 5 under negative pressure;

[0053] At least one second frame 251 having a cover 251c is provided, and a vent hole 251d is provided on the cover 251c for penetrating the upper and lower sides of the cover 251c;

[0054] The lower end of the second frame body 251 is sealedly connected to the first frame body 252 by a second adhesive;

[0055] At least one waterproof breathable membrane 4 is provided and bonded to the outer surface of the cover portion 251c.

[0056] The pressure measurement assembly 2 manufactured by the above manufacturing method can protect the pressure sensitive element 20 and the lead 24 separately through the frame assembly 25, and at the same time, enable the protective gel filled in the frame assembly 25 to smoothly and efficiently discharge bubbles, thereby reducing the measurement error of the pressure sensor.

[0057] The scope of the disclosure is defined not by the detailed description but 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 disclosure.

Claims

1. A pressure sensor, characterized in that: include: The main housing (1) has a pressure introduction channel (11); one end of the pressure introduction channel (11) is used to introduce a pressure medium to be measured, and the second end thereof passes through a mounting plane (14) on a side surface of the main housing (1); A pressure measuring assembly (2) mounted on the mounting plane (14), comprising a pressure sensitive element (20) which is blocked and coupled to the other end of the pressure introduction channel (11); a plurality of electrical connection terminals (6) fixed to the main housing (1), one end of which is electrically connected to the pressure measurement assembly (2); and a connection structure (3) for mechanical connection with external equipment, formed by extending outward from one side of the installation plane (14) of the main housing (1).

2. The pressure sensor according to claim 1, characterized in that: The pressure introduction channel (11) comprises a first portion (11a) extending longitudinally, and a second portion (11b) extending transversely from an inner end of the first portion (11a) and penetrating to the mounting plane (14), and the pressure measuring component (2) is generally arranged longitudinally.

3. The pressure sensor according to claim 1, characterized in that: The mounting plane (14) is arranged at the bottom of a recessed portion (15) formed by the inward recess of the one side surface of the main housing (1).

4. The pressure sensor according to claim 1, characterized in that: One end of the electrical connection terminal (6) is electrically connected to the pressure measurement component (2), and the other end generally extends longitudinally toward a side away from the pressure measurement component (2).

5. The pressure sensor according to claim 1, characterized in that: The connection structure (3) comprises a plurality of buckles formed by extending in a transverse direction from one side of the main housing (1) where the pressure measurement assembly (2) is arranged.

6. The pressure sensor according to any one of claims 1 to 5, characterized in that: The pressure measurement component (2) comprises a substrate (21) fixedly attached to the mounting plane (14); a processing circuit including a plurality of electronic components is arranged on a side of the substrate (21) away from the mounting plane (14); the processing circuit is electrically connected to the one end of the electrical connection terminal (6); and the pressure sensitive element (20) is fixed on a side of the substrate (21) away from the mounting plane (14) and is electrically connected to the processing circuit via a lead (24).

7. The pressure sensor according to claim 6, characterized in that: The electrical connection terminal (6) comprises a transverse portion (61) and a longitudinal portion (62) which are integrally connected, the transverse portion (61) being electrically connected to the processing circuit, and a middle portion of the longitudinal portion (62) forming an elastic portion (63) having elasticity in the longitudinal direction.

8. The pressure sensor according to claim 7, characterized in that: The elastic portion (63) is U-shaped, and two ends of the elastic portion (63) are respectively connected integrally and vertically to two adjacent ends of other parts of the electrical connection terminal (6).

9. The pressure sensor according to claim 6, characterized in that: A protective gel (5) that at least covers the pressure sensitive element (20) and the lead (24) is fixedly arranged on one side of the substrate (21) away from the mounting plane (14).

10. The pressure sensor according to claim 9, characterized in that: The protective gel (5) is contained in a frame assembly (25) fixed to a corresponding side of the substrate (21).

Images