Temperature pressure sensor

Abstract

A temperature pressure sensor capable of reducing the risk that a pressure sensitive element is damaged under the impact of a pressure pulse comprises a shell, an inner side of which forms a mounting cavity and a pressure introduction channel, the inner side of which is communicated with the mounting cavity so as to introduce a medium to be measured; the seat plate is arranged in the mounting cavity and is hermetically fixed at one end of the inner side of the pressure introduction channel; the pressure measuring assembly is arranged in the mounting cavity and comprises a substrate which is fixed on one side, far away from the pressure introduction channel, of the seat plate and is provided with a pressure via hole, a pressure sensitive element which is hermetically fixed on one end, far away from the seat plate, of the pressure via hole, and a circuit board which is arranged on one side, far away from the pressure introduction channel, of the substrate; a zigzag channel is enclosed between the seat plate and the substrate, and one end of the zigzag channel is communicated with the pressure introduction channel towards one side far away from the pressure measurement assembly through a communication hole formed in the seat plate; and the temperature sensitive element is arranged in the pressure introduction channel and is connected with a terminal, and the terminal sequentially penetrates through the seat plate and the substrate from outside to inside and then is electrically connected to the circuit board.

Description

Technical Field

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

[0002] When measuring pressure, existing temperature and pressure sensors usually use semiconductor pressure chips as pressure sensitive elements to measure the pressure of the medium to be measured. The semiconductor pressure chip has a limited tolerable pressure and is more easily damaged when impacted by the pressure pulse of the medium to be measured. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present application provides a temperature pressure sensor to reduce the risk of pressure sensitive elements being damaged under the impact of pressure pulses.

[0004] To achieve the above objectives, the present application provides the following technical solution: a temperature and pressure sensor, comprising:

[0005] The housing has a mounting cavity formed therein and a pressure introduction passage connected to the mounting cavity on the inner side for introducing the medium to be measured;

[0006] A seat plate disposed in the installation cavity and sealed and fixed to one end of the inner side of the pressure introduction channel;

[0007] The pressure measuring assembly arranged in the installation cavity comprises a substrate fixed to the seat plate at a side away from the pressure introduction channel and having a pressure through hole, a pressure sensitive element sealed and fixed to an end of the seat plate away from the pressure through hole, and a circuit board arranged on a side of the substrate away from the pressure introduction channel; a zigzag channel is formed between the seat plate and the substrate, one end of the zigzag channel is connected to the pressure introduction channel toward a side away from the pressure measuring assembly through a connecting hole arranged on the seat plate, and the other end is connected to the other end of the pressure through hole;

[0008] A temperature sensitive element is arranged in the pressure introduction channel and is connected with a terminal. The terminal passes through the seat plate and the base plate in sequence from the outside to the inside and is then electrically connected to the circuit board.

[0009] Preferably, the terminal is fixed to the base plate by molding.

[0010] Preferably, the terminal passes through the seat plate through a terminal through-hole provided on the seat plate, and the terminal and the terminal through-hole are sealed by a sealant.

[0011] Preferably, the terminal passes through the substrate through a terminal via hole provided on the substrate; the substrate is a metal plate or a ceramic plate, and the terminal and the terminal via hole are sealed and fixed by sintered glass.

[0012] Preferably, a groove extending in a zigzag manner is formed on one side surface of the seat plate close to the base plate, and the zigzag channel is formed between the groove and an adjacent side surface of the seat plate.

[0013] Preferably, the seat plate extends toward one side of the pressure introduction channel to form a retaining tube, and a portion of the terminal is accommodated in the retaining tube.

[0014] Preferably, a surface of one side of the seat plate facing the base plate is recessed inwardly to form a circle of rubber groove surrounding the groove.

[0015] Preferably, a side surface of the seat plate facing the substrate extends outward to form a circle of positioning flanges including the glue receiving groove for positioning the substrate.

[0016] Preferably, the substrate is provided with a clearance hole for making way for the pressure sensitive element, and the clearance hole has a step surface facing away from the seat plate; a first circuit is provided on the surface of the side of the substrate away from the seat plate, and a second circuit electrically connected to the first circuit is provided on the step surface, and the pressure sensitive element is electrically connected to the second circuit through a lead; the clearance hole is filled with a protective gel covering the pressure sensitive element and the lead.

[0017] Preferably, the shell is provided with a vent hole, and the inner and outer sides of the vent hole are covered with a waterproof breathable membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. 1 is a schematic structural diagram of a temperature and pressure sensor according to a first embodiment.

[0019] Figure 2 FIG. 4 is a partial structural diagram of a temperature and pressure sensor according to a second embodiment.

[0020] Figure 3 FIG. 1 is a perspective view of the seat plate 3 of the temperature and pressure sensor of the third embodiment.

[0021] In the figure: 10, installation cavity; 11a, concave cavity; 11b, flange; 11c, sealing groove; 11d, vent hole; 11, main shell; 12, top cover; 130, pressure introduction channel; 13, pressure interface; 140, plug pin; 141, plug pin; 14a, outer end; 14b, middle; 14c, inner end; 14, electrical connector; 15, hot riveting column; 1, shell; 20a, lead wire; 20, pressure sensitive element; 21a, pressure through hole; 2 1b, terminal through hole; 21c, glass; 21, substrate; 22a, hole; 22b, metallized hole; 22c, metallized hole; 22d, clearance hole; 22, circuit board; 2, pressure measurement component; 30a, connecting hole; 30d, positioning flange; 30e, glue groove; 30, tortuous channel; 3a, terminal through hole; 3b, retaining tube; 3, seat plate; 41a, top; 41, terminal; 4, temperature sensitive element; 5, sealing ring; 6, waterproof breathable membrane. DETAILED DESCRIPTION

[0022] 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.

[0023] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the products of the present application are usually placed when in use, or the directions or positional relationships usually understood by those skilled in the art, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the equipment or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limitations on the present application. In addition, the prepositive terms "first", "second", "third", etc. are only used to distinguish the modified objects, and cannot be understood as indicating or implying relative importance.

[0024] 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.

[0025] 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.

[0026] See also Figure 1 In the first embodiment, the temperature and pressure sensor includes a housing 1, a seat plate 3, a pressure measuring assembly 2 and a temperature sensitive element 4. The housing 1 may include a main housing 11 with an upper opening and a top cover 12 covering the upper opening of the main housing 11. The main housing 11 and the top cover 12 surround a mounting cavity 10. A pressure interface 13 is connected to the bottom end of the main housing 11, and a pressure introduction channel 130 is formed inside the pressure interface 13 to introduce the medium to be measured. An inner end of the pressure introduction channel 130 is connected to the mounting cavity 10. The seat plate 3 is disposed in the mounting cavity 10 and is sealed and fixed to an inner end of the pressure introduction channel 130. Preferably, a concave cavity 11a is formed on the main housing 11, and the seat plate 3 is disposed in the above-mentioned concave cavity 11a. Correspondingly, the periphery of the concave cavity 11a can also protrude upward to form a circle of flange 11b to increase the depth of the concave cavity 11a.

[0027] The pressure measuring assembly 2 is disposed in the mounting cavity 10, and includes a substrate 21, a circuit board 22, and a pressure sensitive element 20. The substrate 21 is fixed to the side of the seat plate 3 away from the pressure introduction channel 130, and is provided with a pressure through hole 21a that passes through the seat plate 3 from top to bottom. The pressure sensitive element 20 is sealed and fixed to the end of the pressure through hole 21a away from the seat plate 3 (i.e. Figure 1 The circuit board 22 is arranged on the side of the base plate 21 away from the pressure introduction channel 130. A zigzag channel 30 is formed between the seat plate 3 and the base plate 21. One end of the zigzag channel 30 (i.e. Figure 1 The lower end of the pressure sensor 20 is connected to the pressure introduction channel 130 through a connecting hole 30a provided on the seat plate 3 toward the side away from the pressure measuring assembly 2, and the other end of the zigzag channel 30 is connected to the other end of the pressure through hole 21a. Thus, the medium to be measured enters the pressure through hole 21a from the inside to the outside through the pressure introduction channel 130 and the zigzag channel 30 in sequence, and applies pressure to one side of the pressure sensitive element 20. Among them, the pressure sensitive element 20 can be a piezoresistive semiconductor pressure chip, of course, it can also be other suitable types of pressure sensitive elements, such as a capacitive semiconductor pressure chip, etc.

[0028] The temperature sensitive element 4 is disposed in the pressure introduction channel 130. Specifically, it is preferably close to the outside of the pressure introduction channel 130 so that the temperature measured by it is closer to the actual temperature of the medium to be measured. The temperature sensitive element 4 can be a thermistor, such as an NTC element, and terminals 41 are connected to both ends of the NTC element. Terminal 41 is from outside to inside ( Figure 1 The first conductor 21 passes through the seat plate 3 and the base plate 21 in sequence and is then electrically connected to the circuit board 22.

[0029] The seat plate 3 can be sealed and fixed to one end of the inner side of the pressure introduction channel 130 by means of pressure sealing. For example, an electrical connector 14 can be connected to the left side of the main housing 11; the middle part of a plurality of pins 140 is molded in the main housing 11, and the inner end 14c thereof forms a fisheye terminal and passes upward through the metallized hole 22b provided on the circuit board 22, and is fixed and electrically connected to the metallized hole 22b in an interference fit manner, and the outer end 14a thereof extends into the electrical connector 14. In addition, on the right side of the main housing 11, at least one pin 141 whose lower end is molded in the main housing 11 also forms a fisheye terminal at its upper end, and is connected to the metallized hole 22c provided on the circuit board 22 in the same manner. The bottom of the circuit board 22 is supported on the top surface of the substrate 21. In this way, a downward pressure can be applied to the circuit board 22, and the sealing ring 5 can be pressed around the inner end of the pressure introduction channel 130 through the circuit board 22, the base plate 21 and the seat plate 3 in sequence, wherein the sealing ring 5 can be accommodated in the sealing groove 11c formed around the inner end of the pressure introduction channel 130 at the bottom of the installation cavity 10. In addition, the main housing 11 can protrude upward to form at least one heat riveting column 15, which is riveted to the riveting hole (not shown) on the circuit board 22, and can also provide part of the downward pressure.

[0030] The terminal 41 can be fixed on the base plate 3 by molding. The terminal 41 passes through the base plate 3 through the terminal through hole 3a provided on the base plate 3. The terminal 41 and the terminal through hole 3a are sealed by a sealant.

[0031] Alternatively, more preferably, the terminal 41 passes through the substrate 21 through the terminal through hole 21b provided on the substrate 21. The substrate 21 may be a metal plate or a ceramic plate or other plate having a thermal expansion coefficient closer to that of silicon. A sintered glass 21c (see also Figure 2 ) is sealed and fixed. In this way, not only the stress caused by temperature change can be reduced, but also the sealing between the terminal 41 and the substrate 21 can be improved.

[0032] A zigzag groove is formed on one side surface of the seat plate 3 close to the base plate 21. The zigzag channel 30 is formed between the groove and the adjacent side surface of the seat plate 3. In some other schemes, the zigzag channel 30 can also be formed by the above-mentioned groove of the base plate 21 and another groove formed on the bottom surface of the base plate 21.

[0033] The substrate 21 may be provided with a clearance hole 22d for making way for the pressure sensitive element 20. The clearance hole 22d has a step surface facing away from the seat plate 3. A first circuit is provided on the surface of the side of the substrate 21 away from the seat plate 3. A second circuit electrically connected to the first circuit is provided on the step surface. The pressure sensitive element 20 is electrically connected to the second circuit through the lead 20a. The clearance hole 22d is filled with a protective gel covering the pressure sensitive element 20 and the lead 20a. The top end 41a of the terminal 41 can pass upward through the hole 22a provided on the circuit board 22 and then be welded to the hole 22a to be electrically connected to the first circuit. The first circuit and the second circuit can be electrically connected through the via structure provided inside the circuit board 22.

[0034] See also Figure 2 In the second embodiment, preferably, the seat plate 3 extends toward one side of the pressure introduction channel 130 to form a retaining tube 3b. A portion of the terminal 41 is accommodated in the retaining tube 3b. This can avoid deformation of the terminal 41 in some cases and improve operability during installation. The bottom surface of the seat plate 3 can be fixedly sealed to the inner end of the pressure introduction channel 130 by a sealing adhesive.

[0035] See also Figure 3 . In the third embodiment, the side surface of the seat plate 3 facing the substrate 21 may be recessed inward to form a circle of adhesive grooves 30e surrounding the groove. The bottom surface of the substrate 21 is sealed and fixed to the top surface of the seat plate 3 by a sealing adhesive. Preferably, the side surface of the seat plate 3 facing the substrate 21 extends outward to form a circle of positioning flanges 30d including the adhesive grooves 30e for positioning the substrate 21. In particular, the cavity 11a may be filled with a sealing adhesive that submerges the connection between the substrate 21 and the seat plate 3, so that the substrate 21 and the seat plate 3 can be sealed and bonded together by the sealing adhesive, and the adhesive grooves 30e can also be omitted.

[0036] In the above embodiments, a vent hole 11d is provided on the housing 1 to introduce ambient pressure from the environment as a reference pressure. The inner and outer sides of the vent hole 11d are covered with a waterproof breathable membrane 6. The vent hole 11d can pass between the middle parts 14b of the plurality of pins 140 to avoid the pins 140.

[0037] 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 temperature and pressure sensor, characterized in that: include: A housing (1) having an installation cavity (10) formed therein and a pressure introduction channel (130) connected to the installation cavity (10) on the inner side for introducing a medium to be measured; A seat plate (3) disposed in the installation cavity (10) and sealed and fixed to one end of the inner side of the pressure introduction channel (130); A pressure measuring assembly (2) arranged in the mounting cavity (10) comprises a substrate (21) fixed to a side of the seat plate (3) away from the pressure introduction channel (130) and having a pressure through hole (21a), a pressure sensitive element (20) sealed and fixed to an end of the seat plate (3) away from the pressure through hole (21a), and a circuit board (22) arranged on a side of the substrate (21) away from the pressure introduction channel (130); a zigzag channel (30) is formed between the seat plate (3) and the substrate (21); one end of the zigzag channel (30) is connected to the pressure introduction channel (130) toward a side away from the pressure measuring assembly (2) through a connecting hole (30a) arranged on the seat plate (3), and the other end is connected to the other end of the pressure through hole (21a); A temperature sensitive element (4) is arranged in the pressure introduction channel (130), and is connected to a terminal (41). The terminal (41) passes through the seat plate (3) and the base plate (21) in sequence from the outside to the inside, and is then electrically connected to the circuit board (22).

2. The temperature and pressure sensor according to claim 1, characterized in that: The terminal (41) is fixed on the base plate (3) by molding.

3. The temperature and pressure sensor according to claim 2, characterized in that: The terminal (41) passes through the seat plate (3) via a terminal through hole (3a) provided on the seat plate (3), and the terminal (41) and the terminal through hole (3a) are sealed by a sealant.

4. The temperature and pressure sensor according to claim 1, characterized in that: The terminal (41) passes through the substrate (21) via a terminal through hole (21b) provided on the substrate (21); the substrate (21) is a metal plate or a ceramic plate, and the terminal (41) and the terminal through hole (21b) are sealed and fixed by a sintered glass (21c).

5. The temperature and pressure sensor according to any one of claims 1 to 4, characterized in that: A zigzag groove is formed on a side surface of the seat plate (3) close to the base plate (21), and the zigzag channel (30) is formed between the groove and an adjacent side surface of the seat plate (3).

6. The temperature and pressure sensor according to claim 1, characterized in that: The seat plate (3) extends toward one side of the pressure introduction channel (130) to form a retaining tube (3b), and a portion of the terminal (41) is accommodated in the retaining tube (3b).

7. The temperature and pressure sensor according to claim 5, characterized in that: A surface of one side of the seat plate (3) facing the base plate (21) is recessed inwardly to form a circle of rubber receiving grooves (30e) surrounding the groove.

8. The temperature and pressure sensor according to claim 7, characterized in that: A surface of one side of the seat plate (3) facing the base plate (21) extends outward to form a circle of positioning flanges (30d) including the rubber receiving groove (30e) for positioning the base plate (21).

9. The temperature and pressure sensor according to claim 1, characterized in that: The substrate (21) is provided with a clearance hole (22d) for making way for the pressure sensitive element (20), and the clearance hole (22d) has a step surface facing away from the seat plate (3); a first circuit is provided on the surface of the side of the substrate (21) away from the seat plate (3), and a second circuit electrically connected to the first circuit is provided on the step surface, and the pressure sensitive element (20) is electrically connected to the second circuit via a lead wire (20a); the clearance hole (22d) is filled with a protective gel covering the pressure sensitive element (20) and the lead wire (20a).

10. The temperature and pressure sensor according to claim 1, characterized in that: The housing (1) is provided with an air hole (11d), and the inner and outer sides of the air hole (11d) are covered with a waterproof air-permeable membrane (6).

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