A temperature pressure sensor

Abstract

A temperature pressure sensor comprises a housing with a pressure introduction hole; a pressure measurement assembly comprising a metal substrate provided with a downward pressure receiving hole and a metal diaphragm sealed to the upper end of the pressure receiving hole; the metal diaphragm is integrally connected with the metal substrate, and the side surface away from the pressure receiving hole of the metal diaphragm is provided with a pressure measurement circuit; the metal substrate divides the inner cavity of the housing into an upper cavity and a lower cavity; a circuit board fixedly arranged on the upper side of the metal substrate is electrically connected to the pressure measurement circuit through first conductive lines, and the circuit board is provided with a clearance hole allowing the first conductive lines to pass through; a plurality of pins fixedly arranged on the housing have lower ends extending into the upper cavity and being electrically connected to the circuit board through first elastic conductive bodies; and a temperature sensitive element arranged in the pressure introduction hole and having two conductive rods respectively extending from both ends, the upper end of the conductive rod passes through the metal substrate and is electrically connected to the circuit board through a conductive sheet and second conductive lines, 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 problem, 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, the temperature sensitive element is set on an insulating seat, and the electrical connection is realized through a conductive spring, a conductive element (such as a metal probe) and a circuit board. 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 upwardly against 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 with 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), so as to avoid the adverse effects of temperature on the 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, so that the temperature sensitive element can be conveniently connected to the circuit board.

[0007] To achieve the above object, the 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 downward pressure receiving hole and a metal diaphragm plugged on the upper end of the pressure receiving hole; the metal diaphragm is integrally connected with the metal substrate, and the side surface of the metal diaphragm away from the pressure receiving hole is provided with a pressure measurement circuit composed of a strain resistance; the metal substrate divides 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 first conductive lines, and the circuit board being provided with a clearance hole allowing the first conductive lines 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 penetrating through the metal substrate and being electrically connected to the circuit board through a conductive sheet and second conductive lines, and sintered glass being sealed between the conductive rod and the metal substrate.

[0013] Preferably, the shell comprises an end knob, a metal shell and a lower shell, the pressure introduction hole is 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; and the pins are fixed on the end knob.

[0014] Preferably, the temperature pressure sensor further comprises an O-ring, the shell comprises an upper shell and a lower shell fixedly connected with each other, and the O-ring is compressed between the upper end of the compression member and the upper shell.

[0015] Preferably, the edge of the circuit board is fixedly and electrically connected with a conductive sheet, the conductive sheet is compressed downward by a compression member and is electrically connected to the metal substrate; the metal substrate abuts against the lower shell downward; and the compression member is formed with a second through hole for the first elastic conductive body to pass through.

[0016] Preferably, the peripheral edge of the compression member protrudes downward to form at least two second buckles, and the second buckles are clamped on the positioning recesses correspondingly arranged on the outer wall of the circuit board support.

[0017] Preferably, the temperature pressure sensor further comprises an elastic sleeve, the elastic sleeve comprises a thick section on the upper side and a thin section on the lower side, the thick section is integrally connected with the thin section, the thin section is fittedly arranged in the pressure introduction hole; 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.

[0018] Preferably, a first circumferential positioning part corresponding to the inner side wall of the second buckle can be formed on the circuit board.

[0019] Preferably, a part of the lower end of the end knob extends downward into the positioning convex ring, and a second circumferential positioning part is formed on the inner wall of the positioning convex ring and the part of the lower end of the end knob extending downward into the positioning convex ring.

[0020] Preferably, the strain resistance is a thick film resistance, a glass micro-fusion strain resistance or a sputtering thin film resistance.

[0021] Preferably, the strain resistance is a thick film resistance, which is sintered on the metal substrate together with sintered glass. BRIEF DESCRIPTION OF DRAWINGS

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

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

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

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

[0026] In the figure: 101, end knob; 102, metal shell; 103, pin; 1, upper shell; 201, pressure introduction hole; 202, first support step; 204, sealing support surface; 2, lower shell; 30, metal substrate; 312, metal diaphragm; 31, pressure sensitive element; 33, protective layer; 34, lead pad; 351, conductive rod; 352, temperature sensitive element; 353, sintered glass; 3, pressure measurement assembly; 500, first pad; 501, accommodation hole; 502, first circumferential positioning part; 504, electronic element; 505, second pad; 506, first wire; 601, second buckle; 605a, retaining cylinder; 605, second via hole; 607, second circumferential positioning part; 609, positioning convex ring; 6, compression member; 700, cylinder cavity; 701, thin section; 702, thick section; 7, elastic sleeve; 91, first elastic conductor; 92, second wire; 93, conductive sheet; DETAILED DESCRIPTION

[0027] The technical solutions of the present application will be described clearly and completely in combination with the drawings. The following examples are exemplary and are used to explain the present application, but cannot be interpreted as a limitation to the present application. In the following description, the same signs are used to represent the same or equivalent elements, and the repeated description is omitted.

[0028] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly understood by those skilled in the art, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation to the present application.

[0029] In addition, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of 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 the present application specification and corresponding claims means any combination of one or more of the listed items and all possible combinations.

[0031] As shown in Figures 1 to 4 In an embodiment of the present application, the temperature and pressure sensor comprises a shell (not labeled), a pressure measuring assembly 3, and a circuit board. The shell comprises an upper shell 1 and a lower shell 2 made of metal. The upper shell 1 can comprise an end knob 101 and a metal outer shell 102. The upper end of the metal outer shell 102 is embedded in the end knob 101, and the lower end of the metal outer shell 102 is fixed on a first support step 202 formed by sinking the outer periphery of the lower end of the lower shell 2 by welding or the like.

[0032] The pressure measuring assembly 3 comprises a metal substrate 30 and a pressure sensitive element 31. The metal substrate 30 separates the inner cavity of the housing into an upper cavity and a lower cavity. The lower housing 2 is provided with a pressure introduction hole 201 for introducing pressure medium into the lower cavity. The metal substrate 30 is provided with a downward pressure receiving hole. The pressure sensitive element 31 comprises a metal diaphragm 312 integrally connected to the metal substrate 30, which is sealed to the upper end of the pressure receiving hole. The metal diaphragm 312 deforms when the lower side surface thereof receives the pressure of the pressure medium. The side surface of the metal diaphragm 312 away from the pressure receiving hole (i.e. the upper side surface) is provided with a pressure measuring circuit (e.g. a Wheatstone bridge) composed of a plurality of strain resistors. The strain resistors can be thick film resistors, glass micro-fusion strain resistors, sputtering thin film resistors or other resistors capable of changing resistance values due to deformation of the metal diaphragm 312. Among them, since the sintering temperature of the thick film resistors is close to that of the sintering glass 353, the above-mentioned thick film circuit is preferably sintered together with the sintering glass 353 on the metal substrate 30, thereby reducing the process and saving energy. The pressure measuring circuit can be protected by a protective layer 33 (e.g. a glaze layer) and exposed to a plurality of lead pads 34.

[0033] The circuit board is adhered to the upper side surface of the metal substrate 30. The circuit board is electrically connected to the pressure measuring circuit through the first conductive wire 506. The circuit board is provided with a clearance hole 501 allowing the first conductive wire 506 to pass through, so that the signals measured by the pressure measuring circuit can be transmitted to the circuit board. The upper side of the circuit board is provided with electronic elements 504 such as a conditioning chip.

[0034] The temperature and pressure sensor further comprises a plurality of pins 103 for transmitting the signals processed by the circuit board to external devices. The pins 103 can be embedded in the end knob 101, with one end extending outwardly and the other end exposed to the upper cavity after passing through the end knob 101. The exposed part of the pins 103 in the upper cavity forms a one-to-one electrical connection with the plurality of second pads 505 provided on the upper side of the circuit board, for example, through the first elastic conductive body 91. The first elastic conductive body 91 can be a metal spring, but is 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 (e.g. 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 arranged in the pressure introduction hole 201 and has a conductive rod 351 extending from each end thereof. The upper end of the conductive rod 351 passes through the metal substrate 30 and is electrically connected to the circuit board through the conductive sheet second conductive wire 92 or the second flexible conductive body. The conductive rod 351 and the metal substrate 30 are sealed with sintering glass 353 to form a fixed and sealed connection between them and maintain insulation.

[0036] The leading pads 34 on the upper surface of the metal film 312 are electrically connected to the first pads 500 on the upper surface of the circuit board by the first conductive wires 506. The upper surface of the metal substrate 30 is preferably a flat surface. In order to enable the metal shell 102 to be grounded, the edge of the circuit board is also fixedly and electrically connected to a conductive sheet 93. One of the plurality of pins 103 is a ground pin, and the conductive sheet 93 is connected to the ground pin through the circuit board.

[0037] The lower end of the pressing member 6 presses and electrically connects the conductive sheet 93 to the upper end surface of the metal substrate 30. Since the lower end of the metal shell 102 is welded to the lower housing 2, the metal substrate 30 abuts against the lower housing 2, so that the metal shell 102 can be grounded through the ground pads on the circuit board. The pressing member 6 has a second through hole 605 formed therein, through which the first elastic conductive body 91 can pass up and down. The upper end of the pressing member 6 can have a positioning protruding ring 609 protruding upward near the outer edge. In other embodiments, the edge of the second through hole 605 can protrude downward to form a retaining cylinder 605a to prevent the first elastic conductive body 91 from shifting.

[0038] The outer edge of the pressing member 6 can have at least two second buckles 601 protruding downward. The second buckles 601 are buckled to the positioning recesses 403 provided on the outer wall of the circuit board support 4, so that the pressing member 6 can be fixed in advance between the circuit board and the circuit board support 4.

[0039] In other embodiments, the temperature and pressure sensor preferably further comprises an elastic sleeve 7 which is filled between the lower end of the metal substrate 30 and the inner wall of the lower housing 2 to enable the two to be sealingly connected. The elastic sleeve 7 specifically comprises a thick section 702 on the upper side and a thin section 701 on the lower side. The thick section 702 is integrally connected to the thin section 701. The thin section 701 is fitted into the pressure introduction hole 201. The upper end of the thick section 702 abuts against the lower end surface of the metal substrate 30. The lower end abuts against a sealing support surface 204 formed in the lower cavity. The pressure receiving hole communicates downward to the inner cavity of the thick section 702. The temperature sensitive element 352 is located in the lower part of the inner cavity 700 of the thin section 701.

[0040] The circuit board can be formed with a first circumferential positioning part 502 corresponding to the inner side wall of the second buckle 601, so as to fix the pressing member 6 on the circuit board; on this basis, the temperature and pressure sensor can further comprise an O-ring 8, which is squeezed between the upper end of the pressing member 6 and the inner wall of the upper shell 1, and the pressing member 6 is supported downward on the circuit board, so that the pressing member 6, the circuit board and the upper shell 1 are pressed on the metal substrate 30 through the O-ring 8. In order to realize circumferential positioning between the pressing member 6 and the end button 101, a second circumferential positioning part 607 can be formed on the inner wall of the positioning convex ring 609. A part of the lower end of the end button 101 extends into the positioning convex ring 609 downward, and a second circumferential positioning part is correspondingly arranged on the outer wall of the part. Among them, the two corresponding circumferential positioning parts can both be flat edges, or a combination of positioning grooves and positioning ridges, or other structures whose horizontal cross-sectional shapes can be complementary.

[0041] The scope of the 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 interpreted as being included in the disclosure.

Claims

1. A temperature pressure sensor, characterized by, The application relates to a pressure sensor, which comprises the following parts: a shell with a pressure introduction hole (201); a pressure measuring assembly (3) comprising a metal base plate (30) with a downward pressure receiving hole and a metal diaphragm (312) sealingly arranged at the upper end of the pressure receiving hole; the metal diaphragm (312) is integrally connected with the metal base plate (30), and the side surface of the metal diaphragm (312) away from the pressure receiving hole 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; a circuit board fixedly arranged on the upper side of the metal base plate (30), which is electrically connected to the pressure measuring circuit through first conductive wires (506), and is provided with a clearance hole (501) allowing the first conductive wires (506) to pass through; a plurality of pins (103) fixedly arranged on the shell, the lower ends of the pins (103) extending into the upper cavity and being electrically connected to the circuit board through first elastic conductive bodies (91); and a temperature sensitive element (352) arranged in the pressure introduction hole (201) and having two conductive rods (351) respectively extending out from the two ends, the upper end of the conductive rod (351) penetrating through the metal base plate (30) and being electrically connected to the circuit board through a conductive sheet and second conductive wires (92), and the conductive rod (351) and the metal base plate (30) being sealed by sintered glass (353); wherein the edge of the circuit board is fixedly and electrically connected to a conductive sheet (93), the conductive sheet (93) is pressed downward by a pressing member (6) and is electrically connected to the metal base plate (30); the metal base plate (30) abuts against the lower shell (2) downward; the pressing member (6) is formed with a second through hole (605) allowing the first elastic conductive bodies (91) to pass through upward and downward; one of the plurality of pins (103) is a grounding pin, and the conductive sheet (93) is connected to the grounding pin through the circuit board.

2. The temperature pressure sensor of claim 1, wherein, The shell comprises an end knob (101), a metal shell (102) and a lower shell (2), the pressure introduction hole (201) is arranged on the lower shell (2); the upper end of the metal shell (102) is embeddedly fixed on the end knob (101), and the lower end is sealingly connected with the lower shell (2); the pins (103) are fixed on the end knob (101).

3. The temperature pressure sensor of claim 1, wherein, The peripheral edge of the pressing member (6) protrudes downward to form at least two second buckles (601), which are clamped on the positioning recesses (403) correspondingly arranged on the outer wall of the circuit board support (4).

4. The temperature pressure sensor of claim 1, wherein, An O-shaped ring (8) is further arranged, the shell comprises an upper shell (1) and a lower shell (2) fixedly connected in sequence, and the O-shaped ring (8) is arranged between the upper end of the pressing member (6) and the upper shell (1).

5. The temperature pressure sensor of claim 1, wherein, The elastic sleeve (7) comprises a thick section (702) on the upper side and a thin section (701) on the lower side, the thick section (702) is integrally connected with the thin section (701), and the thin section (701) is matchedly 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 base plate (30), and the lower end is pressed against a sealing support surface (204) formed in the lower cavity; the pressure receiving hole is downwardly communicated 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).

6. The temperature pressure sensor of claim 1, wherein, A first circumferential positioning part (502) corresponding to the inner side wall of the second buckle (601) can be formed on the circuit board.

7. The temperature pressure sensor of claim 1, wherein, A part of the lower end of the end knob (101) downwardly extends into the positioning convex ring (609), and a second circumferential positioning part (607) is formed on the inner wall of the positioning convex ring (609) and the part of the lower end of the end knob (101) downwardly extending into the positioning convex ring (609).

8. The temperature pressure sensor of claim 1, wherein, The strain resistance is a thick film resistance, a glass micro-fusion strain resistance or a sputtering thin film resistance.

9. The temperature pressure sensor according to any one of claims 1 to 8, characterized in that, The strain resistance is a thick film resistance, and the thick film resistance is sintered on the metal base plate (30) together with the sintered glass (353).

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