A temperature pressure sensor

Abstract

A temperature sensitive element can be electrically connected to a temperature pressure sensor of a circuit board, comprising: a housing having a pressure introduction hole; a pressure measuring assembly comprising a metal substrate provided with a pressure receiving hole and a metal diaphragm sealed to the upper end of the pressure receiving hole, a pressure measuring circuit composed of strain resistance is arranged on the side surface of the metal diaphragm away from the pressure receiving hole; the metal substrate separates the inner cavity of the housing into an upper cavity and a lower cavity; a circuit board is fixedly arranged on the upper side of the metal substrate and is electrically connected to the pressure measuring circuit through a lead wire, the circuit board is provided with a clearance hole allowing the lead wire or the metal diaphragm to pass through; a plurality of pins are fixedly arranged on the housing, the lower end of the pins extends into the upper cavity and is electrically connected to the circuit board through a first elastic conductor; and a temperature sensitive element is arranged in the pressure introduction hole and has a conductive rod extending from each end, the upper end of the conductive rod passes through the metal substrate and is electrically connected to the circuit board through a second elastic conductor, and sintered glass is sealed between the conductive rod and the metal substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure sensors, in particular to a temperature pressure sensor. BACKGROUND

[0002] Liquid carbon dioxide has a wide range of applications in the fire fighting, refrigeration and power industries. At room temperature, the pressure of liquid carbon dioxide can be as high as tens of megapascals. High-range pressure sensors for measuring such high pressures cannot be made by MEMS (micro-mechanical system) technology, and are generally made by metal diaphragm technology, and also need to set up a temperature sensitive element to detect the temperature. The existing metal diaphragm type temperature pressure sensor, because of the setting of the temperature sensitive element, the temperature sensitive element needs to pass through the metal substrate and be sealed with it. This makes the electrical connection of the temperature sensing element and the processing circuit a difficult problem.

[0003] For the above-mentioned difficulties, there are mainly two existing processing methods. One method is as disclosed in CN102980714A and CN107817015A, an integrated pressure and temperature sensor, which isolates the temperature sensing element from the measured medium by a well heat-conducting metal shell, so that the temperature sensing element and the pressure sensing element do not need to be separated, but a heat-conducting material must be filled between the metal shell and the temperature sensor element. Due to the existence of temperature gradient, the accuracy of the measured temperature data is low, the response time is long, and the process is complicated.

[0004] The other method is as disclosed in CN112611504A, which sets the temperature sensitive element on an insulating seat and realizes electrical connection with the circuit board through a conductive spring and a conductive element (such as a metal probe). However, in the actual manufacture of the above-mentioned temperature pressure sensor, there are the following difficulties: first, the upper end of the conductive spring is elastically abutted upward to the lower end of the conductive element, and the connection between the two is prone to failure after long-term use, especially under vibration working conditions; second, when sealing the conductive element passing through the substrate, a complex via metallization process needs to be used, i.e. first plating with Mo-Mn alloy, then plating a layer of metal Ni, and then soldering with Au-Cu alloy solder, so as to achieve the transition and adaptation of the coefficient of thermal expansion (CTE, coefficient of thermal expansion) to avoid the adverse effects of temperature on measurement accuracy.

[0005] The statements in this section merely provide background information related to the present application and can not constitute the prior art. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a temperature pressure sensor to conveniently electrically connect the temperature sensitive element to the circuit board.

[0007] To achieve the above object, the present application provides the following technical scheme: a temperature pressure sensor, comprising:

[0008] a shell having a pressure introduction hole;

[0009] a pressure measurement assembly comprising a metal substrate provided with a pressure receiving hole and a metal diaphragm sealed on the upper end of the pressure receiving hole, the side surface of the metal diaphragm away from the pressure receiving hole being provided with a pressure measurement circuit composed of a strain resistance; the metal substrate separates the inner cavity of the shell into an upper cavity and a lower cavity;

[0010] a circuit board fixedly arranged on the upper side of the metal substrate, the circuit board being electrically connected to the pressure measurement circuit through wires, the circuit board being provided with a clearance hole allowing the wires or the metal diaphragm to pass through;

[0011] a plurality of pins fixedly arranged on the shell, the lower ends of the pins extending into the upper cavity and being electrically connected to the circuit board through first elastic conductive bodies;

[0012] and a temperature sensitive element arranged in the pressure introduction hole and having a conductive rod led out from each end, the upper end of the conductive rod passing through the metal substrate and being electrically connected to the circuit board through a second elastic conductive body, the conductive rod and the metal substrate being sealed with sintered glass.

[0013] Preferably, the shell comprises an end knob, a metal shell and a lower shell, the pressure introduction hole being arranged on the lower shell; the upper end of the metal shell is embedded in the end knob, the lower end is sealingly connected with the lower shell; the pins are fixedly arranged on the end knob.

[0014] Preferably, a circuit board support made of insulating material is arranged between the pressure measurement assembly and the circuit board, the circuit board, the circuit board support and the pressure measurement assembly being fixedly connected in sequence from top to bottom, the circuit board support being provided with a clearance hole allowing the wires or the metal diaphragm to pass through.

[0015] Preferably, the edges of the clearance hole of the circuit board support are protruded downward to form a plurality of first buckles, the first buckles being clamped on the first bosses formed on the upper surface of the metal substrate.

[0016] Preferably, the circuit board support is protruded upward to form a plurality of riveting columns, the riveting columns being riveted upward on a plurality of mounting holes arranged on the circuit board.

[0017] Preferably, the temperature pressure sensor further comprises a third elastic conductive body passing through a first via hole arranged on the circuit board support from top to bottom, the upper end of the third elastic conductive body being abuttingly and electrically connected to a ground pad arranged on the lower end surface of the circuit board, the lower end of the third elastic conductive body being abuttingly and electrically connected to the upper end surface of the metal substrate; the metal substrate is abuttingly arranged on the lower shell.

[0018] Preferably, the pressing assembly for pressing the circuit board downwardly comprises a pressing member abutting against the circuit board at a lower end, and an O-ring is arranged between the upper end of the pressing member and the upper part of the housing, and the second through hole is formed in the pressing member for the first elastic conductor to pass through.

[0019] Preferably, the periphery of the pressing member is downwardly protruded to form at least two second buckles, and the second buckles are engaged with the positioning recesses arranged on the outer wall of the circuit board support.

[0020] Preferably, the temperature and pressure sensor further comprises an elastic sleeve, the elastic sleeve comprises a thick section at the upper side and a thin section at the lower side, the thick section is integrally connected with the thin section, and the thin section is arranged in the pressure introduction hole in a matched manner; the upper end of the thick section abuts against the lower end surface of the metal substrate, and the lower end abuts against a sealing support surface formed in the lower cavity; the pressure receiving hole is downwardly communicated to the inner cavity of the thick section; and the temperature sensitive element is located at the lower part of the inner cavity of the thin section.

[0021] Preferably, the strain resistance is composed of a thick film resistance, a glass micro-melting strain resistance or a sputtering thin film resistance. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The exploded view of the temperature and pressure sensor of a preferred embodiment of the present application;

[0023] Figure 2 The top view of the temperature and pressure sensor of a preferred embodiment of the present application;

[0024] Figure 3 The sectional view of the temperature and pressure sensor of a preferred embodiment of the present application along Figure 2 A-A shown;

[0025] Figure 4 The sectional view of the temperature and pressure sensor of a preferred embodiment of the present application along Figure 2 B-B shown;

[0026] In the figure: 101, end button; 102, metal shell; 103, pin; 1, upper shell; 201, pressure introduction hole; 202, first support step; 204, sealing support surface; 2, lower shell; 300, pressure receiving hole; 30, metal substrate; 311, cylinder; 312, metal diaphragm; 31a, first circumferential positioning part; 31, pressure sensitive element; 32a, first circumferential positioning part; 32, first boss; 33, protective layer; 34, lead pad; 351, conductive rod; 352, temperature sensitive element; 353, sintered glass; 3, pressure measurement assembly; 402, second circumferential positioning part; 403, positioning recess; 404, riveting column; 405, clearance hole; 406, first buckle; 407, first via hole; 408, first circumferential positioning part; 4, circuit board support; 501, clearance hole; 502, second circumferential positioning part; 503, mounting hole; 504, electronic element; 505, second pad; 506, wire; 507, first circumferential positioning part; 5, circuit board; 601, second buckle; 602, pressure foot; 605a, holding cylinder; 605, second via hole; 607, third circumferential positioning part; 609, positioning convex ring; 6, compression member; 700, cylinder cavity; 701, thin section; 702, thick section; 7, elastic sleeve; 8, O-ring; 91, first elastic conductor; 92, second elastic conductor; 93, third elastic conductor; DETAILED DESCRIPTION

[0027] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. The following examples are exemplary and are used only to explain the present application, and cannot be interpreted as a limitation on the present application. In the following description, the same reference signs 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 terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0029] In addition, the terms "mounting", "connecting", "connection" should be broadly understood, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

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

[0031] like Figures 1 to 4 As shown. In one embodiment of the present application, the temperature and pressure sensor includes a housing (not labeled), a pressure measurement assembly 3, and a circuit board 5. The housing includes an upper housing 1 and a metal lower housing 2. The upper housing 1 may include a terminal 101 and a metal shell 102. The upper end of the metal shell 102 is embedded in the terminal 101, and the lower end of the metal shell 102 is fixed to a first support step 202 formed by sinking the outer periphery of the lower end of the lower housing 2 by welding or other means.

[0032] The pressure measuring assembly 3 includes a metal substrate 30 and a pressure sensitive element 31. The metal substrate 30 divides the inner cavity of the shell into an upper cavity and a lower cavity. A pressure introduction hole 201 for introducing a pressure medium into the lower cavity is provided on the lower shell 2. A pressure receiving hole 300 is provided on the metal substrate 30. The pressure sensitive element 31 includes a roughly horizontal metal diaphragm 312 and a tube 311 formed by the edge of the metal diaphragm 312 protruding downward. The lower end of the tube 311 is integrally connected or welded to the upper end of the metal substrate 30 and is sealed to the upper end of the pressure receiving hole 300. The lower surface of the metal diaphragm 312 receives the pressure of the pressure medium and is deformed. A pressure measurement circuit (such as a Wheatstone bridge) composed of several strain resistors is provided on the side surface of the metal diaphragm 312 away from the pressure receiving hole 300 (i.e., the upper surface). These strain gauge resistors can be thick-film resistors, glass micro-fused strain gauge resistors, sputtered thin-film resistors, or other resistors whose resistance value changes in response to deformation of the metal diaphragm 312. Because the sintering temperatures of the thick-film resistors and the fritted glass 353 are relatively close, the thick-film circuit and the fritted glass 353 are preferably sintered together on the metal substrate 30, thereby reducing process steps and saving energy. In this case, the pressure sensor 31 is preferably integrally connected to the metal substrate 30. The pressure measurement circuit can be covered with a protective layer 33 (e.g., a glaze layer) for protection, exposing a plurality of lead pads 34.

[0033] Circuit board 5 is fixedly mounted on the upper side of metal substrate 30. Circuit board 5 is electrically connected to the pressure measurement circuit via wires 506. Circuit board 5 is provided with a clearance hole 501 to allow wires 506 or metal diaphragm 312 to pass through, allowing the signal measured by the pressure measurement circuit to be transmitted to circuit board 5. Electronic components 504, such as a conditioning chip, are mounted on the upper side of circuit board 5.

[0034] The temperature and pressure sensor further comprises a plurality of pins 103 for transmitting the processed signals of the circuit board 5 to external devices. The pins 103 are embedded in the end knob 101, with one end extending outwardly and the other end exposed to the upper cavity through the lower part of the end knob 101. The exposed part of the pins 103 in the upper cavity is in one-to-one electrical connection with the plurality of second pads 505 provided on the upper side of the circuit board 5, for example, through the first elastic conductive body 91. The first elastic conductive body 91 can be a metal spring, but preferably a connecting spring. In other embodiments, the exposed part of the pins 103 in the upper cavity can also be welded to the second pads 505 through a flexible conductive body (such as a flexible circuit board) to form an electrical connection.

[0035] The temperature and pressure sensor further comprises a temperature-sensitive element 352. The temperature-sensitive element 352 is provided in the pressure introduction hole 201 and has a conductive rod 351 extending from each end. The upper end of the conductive rod 351 is electrically connected to the circuit board 5 through the second elastic conductive body 92 or the second flexible conductive body after passing through the metal substrate 30. The conductive rod 351 and the metal substrate 30 are sealed with sintered glass 353 to form a fixed and sealed connection between the metal substrate 30 and the conductive rod 351, and to maintain insulation.

[0036] In other embodiments, the pressure measurement assembly 3 and the circuit board 5 can be separated by a circuit board support 4 made of insulating material. The circuit board 5, the circuit board support 4, and the pressure measurement assembly 3 are sequentially and fixedly connected. The circuit board support 4 is provided with a clearance hole 405 for allowing the lead wire 506 or the metal diaphragm 312 to pass through. The lead-out pad 34 on the upper surface of the metal diaphragm 312 is electrically connected to the plurality of first pads (not labeled) provided on the upper surface of the circuit board 5 through the lead wire 506. The metal diaphragm 312 can extend upwardly into the clearance hole 405, or further extend upwardly into the clearance hole 501, or further extend upwardly out of the clearance hole 501. To reduce the length of the lead wire 506, the upper surface of the lead-out pad 34 is preferably flush with or close to the upper surface of the first pad. The circuit board support 4 can be upwardly protruding to form a plurality of riveting columns 404, which are riveted to the plurality of mounting holes 503 provided on the circuit board 5. Preferably, the edges of the clearance hole 405 of the circuit board support 4 can also be downwardly protruding to form a plurality of first buckles 406. The first buckles 406 are clamped to the outer periphery of the first boss 32 formed on the upper surface of the metal substrate 30.

[0037] In order to enable the metal shell 102 to be grounded, the temperature pressure sensor further comprises a third elastic conductor 93. The third elastic conductor 93 passes through the first through hole 407 provided on the circuit board support 4. The upper end of the third elastic conductor 93 abuts against and is electrically connected to the ground pad (not shown) provided on the lower end face of the circuit board 5. The lower end of the third elastic conductor 93 abuts against and is electrically connected to the upper end face of the metal base plate 30. Since the lower end of the metal shell 102 is welded to the lower housing 2, the metal base plate 30 abuts against the lower housing 2 downwardly, so that the metal shell 102 can be grounded through the ground pad on the circuit board 5.

[0038] In other embodiments, in order to facilitate the fixation of the pressure measuring assembly 3, the circuit board support 4 and the circuit board 5 in the inner cavity, the temperature pressure sensor can further comprise a pressing assembly for pressing the circuit board 5 downwardly, so as to press and fix them in the cavity. The pressing assembly can comprise a pressing member 6. The lower end of the pressing member 6 can form a plurality of pressing feet 602 which press against the circuit board 5 downwardly. The pressing member 6 is internally formed with a second through hole 605 through which the first elastic conductor 91 passes. An O-ring 8 is provided between the upper end of the pressing member 6 and the upper part of the housing, for example, the upper end of the pressing member 6 can be formed with a positioning protruding ring 609 which protrudes upwardly near the outer edge. The outer edge of the upper end of the pressing member 6 is relatively formed with a positioning step face. The O-ring 8 is sleeved on the positioning step face of the pressing member 6, and the upper end is pressed by the inner wall of the metal shell 102, so that the pressing fixation can be achieved while avoiding the difficulty in assembly caused by the height dimension deviation of the components. In other embodiments, the edge of the second through hole 605 can be formed with a retaining cylinder 605a which protrudes downwardly, so as to avoid the displacement of the first elastic conductor 91.

[0039] In other embodiments, the outer edge of the pressing member 6 can be formed with at least two second buckles 601 which protrude downwardly. The second buckles 601 are buckled on the corresponding positioning recesses 403 provided on the outer wall of the circuit board support 4, so that the pressing member 6 can be preliminarily fixed with the circuit board 5 and the circuit board support 4.

[0040] In other embodiments, preferably, the temperature pressure sensor can further comprise an elastic sleeve 7 which is pressed between the lower end of the metal base plate 30 and the inner wall of the lower housing 2 to enable the sealing connection of the two. The elastic sleeve 7 specifically comprises a thick segment 702 on the upper side and a thin segment 701 on the lower side. The thick segment 702 is integrally connected with the thin segment 701. The thin segment 701 is cooperatively provided in the pressure introduction hole 201. The upper end of the thick segment 702 abuts against the lower end face of the metal base plate 30. The lower end abuts against a sealing support face 204 formed in the lower cavity. The pressure receiving hole 300 downwardly communicates to the inner cavity of the thick segment 702. The temperature sensitive element 352 is located in the lower part of the inner cavity 700 of the thin segment 701.

[0041] In order to achieve circumferential positioning between components when assembling the temperature and pressure sensor, when the pressure sensitive element 31 is inserted into or passed out of the accommodating hole 501 upwardly, the accommodating hole 501 of the circuit board 5, the accommodating hole 405 of the circuit board support 4, and the first circumferential positioning part 31a on the pressure sensitive element 31 are correspondingly formed with first circumferential positioning parts 507, 408, 31a which achieve circumferential positioning of the three. The inner side of the second buckle 601 can abut against these first circumferential positioning parts. The circumferential wall of the first boss 32 can also be correspondingly formed with a first circumferential positioning part 32a. When the pressure sensitive element 31 is not inserted into the accommodating hole 501 upwardly, the first circumferential positioning part 507 can be omitted accordingly. In addition, the circuit board 5 and the circuit board support 4 can be formed with second circumferential positioning parts 502, 402 corresponding to the inner side wall of the second buckle 601. In addition, in order to achieve circumferential positioning between the pressing member 6 and the end button 101, the inner wall of the positioning boss 609 can be formed with a third circumferential positioning part 607. A part of the lower end of the end button 101 is inserted into the positioning boss 609 downwardly and is correspondingly provided with a third circumferential positioning part. Among these corresponding circumferential positioning parts, both can be straight edges, or can be a combination of positioning grooves and positioning ridges, or can be other two structures whose horizontal cross-sectional shapes can be complementary.

[0042] The scope of the disclosure is not limited by the detailed description, but is instead defined by the claims, with equivalents of the claims to be included within the scope of the disclosure.

Claims

1. A temperature pressure sensor, characterized by, The application relates to a pressure sensor, which comprises a shell, a pressure measuring assembly (3), a circuit board (5), a plurality of pins (103), a circuit board support (4), a temperature sensitive element (352) and a third elastic conductor (93). The shell has a pressure introduction hole (201); the pressure measuring assembly (3) comprises a metal base plate (30) provided with a pressure receiving hole (300) and a metal diaphragm (312) sealed on the upper end of the pressure receiving hole (300), and the side surface of the metal diaphragm (312) away from the pressure receiving hole (300) is provided with a pressure measuring circuit composed of strain resistance; the metal base plate (30) divides the inner cavity of the shell into an upper cavity and a lower cavity; the circuit board (5) is fixedly arranged on the upper side of the metal base plate (30) and is electrically connected to the pressure measuring circuit through wires (506); the circuit board (5) is provided with a clearance hole (501) allowing the wires (506) or the metal diaphragm (312) to pass through; the pins (103) are fixedly arranged on the shell and the lower ends of the pins (103) extend into the upper cavity and are electrically connected to the circuit board (5) through first elastic conductors (91); the circuit board support (4) made of insulating material is arranged between the pressure measuring assembly (3) and the circuit board (5); the third elastic conductor (93) passes through the first through hole (407) arranged on the circuit board support (4) and the upper end of the third elastic conductor (93) is abutted against and electrically connected to a ground pad arranged on the lower end surface of the circuit board (5); the lower end of the third elastic conductor (93) is abutted against and electrically connected to the upper end surface of the metal base plate (30); and the temperature sensitive element (352) is arranged in the pressure introduction hole (201) and two conductive rods (351) are respectively arranged at the two ends of the temperature sensitive element (352); the upper ends of the conductive rods (351) pass through the metal base plate (30) and are electrically connected to the circuit board (5) through second elastic conductors (92); and the sintered glass (353) is sealed between the conductive rods (351) and the metal base plate (30). The shell comprises an end knob (101), a metal shell (102) and a lower shell (2), and the pressure introduction hole (201) is arranged on the lower shell (2); the upper end of the metal shell (102) is embedded in the end knob (101) and the lower end is sealingly connected to the lower shell (2); and the pins (103) are fixed on the end knob (101). The circuit board (5), the circuit board support (4) and the pressure measuring assembly (3) are sequentially fixed and connected in sequence from top to bottom, and the circuit board support (4) is provided with a clearance hole (405) allowing the wires (506) or the metal diaphragm (312) to pass through. The edges of the clearance hole (405) of the circuit board support (4) are downwardly protruded to form a plurality of first buckles (406), and the first buckles (406) are clamped on the first bosses (32) formed on the upper surface of the metal base plate (30). The circuit board support (4) is upwardly protruded to form a plurality of riveting columns (404), and the riveting columns (404) are upwardly riveted on a plurality of mounting holes (503) arranged on the circuit board (5). The metal base plate (30) is downwardly abutted against the lower shell (2); the shell comprises an end knob (101), a metal shell (102) and a lower shell (2), and the pressure introduction hole (201) is arranged on the lower shell (2). ​ 2. The temperature pressure sensor of claim 1, wherein, ​ 3. The temperature pressure sensor of claim 1, wherein, ​ 4. The temperature pressure sensor of claim 3, wherein, ​ 5. The temperature pressure sensor of claim 3, wherein, ​ 6. The temperature pressure sensor of claim 3, wherein, ​ 7. The temperature pressure sensor of claim 1, wherein, The invention also includes a pressing assembly for pressing the circuit board (5) downward, including a pressing member (6) whose lower end presses against the circuit board (5), an O-ring (8) is arranged between the upper end of the pressing member (6) and the upper part of the shell, and a second through hole (605) is formed in the pressing member (6) for the first elastic conductor (91) to pass through up and down.

8. The temperature pressure sensor of claim 7, wherein, The periphery of the pressing member (6) protrudes downward to form at least two second buckles (601), and the second buckles (601) are clamped on corresponding positioning recesses (403) provided on the outer wall of the circuit board support member (4).

9. The temperature pressure sensor of claim 1, wherein, The invention also includes an elastic sleeve (7), the elastic sleeve (7) including a thick section (702) on the upper side and a thin section (701) on the lower side, the thick section (702) and the thin section (701) being integrally connected, and the thin section (701) being cooperatively arranged in the pressure introduction hole (201); the upper end of the thick section (702) is pressed against the lower end surface of the metal substrate (30), and the lower end is pressed against a sealing support surface (204) formed in the lower cavity; the pressure receiving hole (300) is downwardly connected to the inner cavity of the thick section (702); and the temperature sensitive element (352) is located at the lower part of the inner cavity of the thin section (701).

10. The temperature pressure sensor according to any one of claims 1 to 9, characterized in that, The strain resistor is a thick film resistor, a glass micro-melted strain resistor or a sputtered thin film resistor.

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