A temperature pressure sensor

Abstract

A temperature pressure sensor capable of reducing the risk of damage to a pressure sensitive element under the impact of a pressure pulse, comprising: a housing, an installation cavity is formed inside, and a pressure introduction channel is communicated to the inside of the installation cavity to introduce the medium to be measured; a seat plate arranged in the installation cavity and sealed and fixed to one end of the inside of the pressure introduction channel; a pressure measurement assembly arranged in the installation cavity, comprising a base plate fixed to the seat plate away from the pressure introduction channel and having a pressure through hole, a pressure sensitive element sealed and fixed to one end of the pressure through hole away from the seat plate, and a circuit board arranged on the base plate away from the pressure introduction channel; a meandering channel is formed between the seat plate and the base plate, one end of the meandering channel is communicated to the pressure introduction channel away from the pressure measurement assembly through a communication hole arranged on the seat plate; a temperature sensitive element arranged in the pressure introduction channel, which is connected with a terminal, the terminal sequentially passes through the seat plate and the base plate from outside to inside and is electrically connected to the circuit board.

Description

Technical Field

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

[0002] Existing temperature and pressure sensors typically use semiconductor pressure chips as pressure-sensitive elements to measure the pressure of the medium being measured. However, semiconductor pressure chips have limited pressure tolerance and are more susceptible to damage when subjected to pressure pulses from the medium being measured. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides a temperature and pressure sensor to reduce the risk of pressure-sensitive elements being damaged by pressure pulses.

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

[0005] The housing has an internal mounting cavity and an internal pressure introduction channel that connects to the mounting cavity to introduce the medium to be measured.

[0006] A seat plate is installed inside the mounting cavity and sealed and fixed to one end of the inner side of the pressure inlet channel;

[0007] The pressure measuring assembly disposed within the mounting cavity includes a base plate fixed to the side of the base plate away from the pressure inlet channel and having a pressure through hole, a pressure sensitive element sealed and fixed to the pressure through hole at one end away from the base plate, and a circuit board disposed on the side of the base plate away from the pressure inlet channel; the base plate and the base plate form a tortuous channel, one end of the tortuous channel being connected to the pressure inlet channel via a through hole disposed on the base plate towards the side away from the pressure measuring assembly, and the other end being connected to the other end of the pressure through hole;

[0008] A temperature-sensitive element is disposed in the pressure introduction channel and is connected to a terminal. The terminal passes through the base plate and the substrate 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 base plate via a terminal through hole provided on the base plate, and the terminal and the terminal through hole are sealed with sealant.

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

[0012] Preferably, a meandering groove is formed on the side surface of the base plate near the substrate, and the meandering channel is formed between the groove and the adjacent side surface of the base plate.

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

[0014] Preferably, the side surface of the base plate facing the substrate is recessed inward to form a ring of adhesive grooves surrounding the groove.

[0015] Preferably, the side surface of the base plate facing the substrate extends outward to form a positioning flange including the adhesive groove for positioning the substrate.

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

[0017] Preferably, the housing is provided with a vent hole, and the inner and outer sides of the vent hole are covered with a waterproof and breathable membrane. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the temperature and pressure sensor in the first embodiment.

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

[0020] Figure 3 This is a perspective view of the base plate 3 of the temperature and pressure sensor in the third embodiment.

[0021] In the diagram: 10. Mounting cavity; 11a. Recessed cavity; 11b. Flange; 11c. Sealing groove; 11d. Vent hole; 11. Main housing; 12. Top cover; 130. Pressure inlet channel; 13. Pressure interface; 140. Pin; 141. Pin; 14a. Outer end; 14b. Middle part; 14c. Inner end; 14. Electrical connector; 15. Hot-fitting post; 1. Housing; 20a. Lead wire; 20. Pressure sensitive element; 21a. Pressure through hole; 2 1b. Terminal via; 21c. Glass element; 21. Substrate; 22a. Hole; 22b. Metallized hole; 22c. Metallized hole; 22d. Clearance hole; 22. Circuit board; 2. Pressure measurement assembly; 30a. Connecting hole; 30d. Positioning flange; 30e. Adhesive tank; 30. Twisted channel; 3a. Terminal via; 3b. Retaining tube; 3. Sealing plate; 41a. Top; 41. Terminal; 4. Temperature sensitive element; 5. Sealing ring; 6. Waterproof and breathable membrane. Detailed Implementation

[0022] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the following description, the same reference numerals are used to denote the same or equivalent elements, and repeated descriptions are omitted.

[0023] In the description of this application, it should be understood that the terms "upper," "lower," "inner," "outer," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the prepositions "first," "second," and "third," etc., are only used for the purpose of distinguishing the modified objects, and should not be construed as indicating or implying relative importance.

[0024] Furthermore, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] It should also be further understood that the term "and / or" as used in this application specification and the corresponding claims refers to any combination of one or more of the listed items and all possible combinations.

[0026] Please see Figure 1 In the first embodiment, the temperature and pressure sensor includes a housing 1, a base plate 3, a pressure measuring assembly 2, and a temperature sensing 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 form a mounting cavity 10. A pressure port 13 is connected to the bottom end of the main housing 11, and a pressure inlet channel 130 is formed inside the pressure inlet channel 13 to introduce the medium to be measured. One inner end of the pressure inlet channel 130 communicates with the mounting cavity 10. The base plate 3 is disposed within the mounting cavity 10 and sealed and fixed to one inner end of the pressure inlet channel 130. Preferably, a recess 11a is formed on the main housing 11, and the base plate 3 is disposed within the recess 11a. Correspondingly, the periphery of the recess 11a may also protrude upwards to form a flange 11b to increase the depth of the recess 11a.

[0027] The pressure measuring assembly 2 is disposed within the mounting cavity 10 and includes a base plate 21, a circuit board 22, and a pressure-sensitive element 20. The base plate 21 is fixed to the side of the base plate 3 away from the pressure inlet channel 130, and has a vertically penetrating pressure through-hole 21a therein. The pressure-sensitive element 20 is sealed and fixed to the end of the pressure through-hole 21a away from the base plate 3 (i.e.,...). Figure 1 The upper end of the substrate 21 is used to receive the pressure of the medium to be measured. Circuit board 22 is disposed on the side of substrate 21 away from pressure inlet channel 130. A tortuous channel 30 is formed between the base plate 3 and substrate 21. One end of the tortuous channel 30 (i.e., the upper end of the base plate 3) is used to receive the pressure of the medium to be measured. Figure 1 The lower end of the pressure sensor 20 (the medium to be measured) is connected to the pressure inlet channel 130 through a through hole 30a on the base plate 3, which is located away from the pressure measuring component 2. The other end of the tortuous 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 out through the pressure inlet channel 130 and the tortuous channel 30, and applies pressure to one side of the pressure sensing element 20. The pressure sensing element 20 can be a piezoresistive semiconductor pressure chip, or other suitable types of pressure sensing elements, such as a capacitive semiconductor pressure chip.

[0028] The temperature-sensitive element 4 is disposed within the pressure inlet channel 130, specifically, preferably near the outer side of the pressure inlet channel 130, so that the temperature it measures is closer to the true temperature of the medium being measured. The temperature-sensitive element 4 can be a thermistor, such as an NTC element, with terminals 41 connected to its two ends. Terminals 41 are arranged from the outside inwards... Figure 1 (From bottom to top) it passes through the base plate 3 and the base plate 21 in sequence and is then electrically connected to the circuit board 22.

[0029] The base plate 3 can be sealed and fixed to one end of the pressure inlet channel 130 by 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, the inner end 14c of which forms a fish-eye 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 by interference fit, while the outer end 14a extends into the electrical connector 14. In addition, on the right side of the main housing 11, at least one pin 141 with its lower end molded in the main housing 11 also forms a fish-eye 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 is pressed against the inner end of the pressure introduction channel 130 in sequence through the circuit board 22, the substrate 21, and the base plate 3. The sealing ring 5 can be accommodated in a sealing groove 11c formed at the bottom of the mounting cavity 10 around the inner end of the pressure introduction channel 130. In addition, the main housing 11 can protrude upward to form at least one hot riveting post 15, which is riveted to a riveting hole (not shown) on the circuit board 22, and can also provide part of the downward pressure.

[0030] Terminal 41 can be molded and fixed to the base plate 3. Terminal 41 passes through the base plate 3 through a terminal through hole 3a. Terminal 41 and terminal through hole 3a are sealed with sealant.

[0031] Alternatively, and more preferably, terminal 41 passes through terminal via 21b provided on substrate 21. Substrate 21 can be a metal plate, ceramic plate, or other material with a coefficient of thermal expansion closer to that of silicon. A sintered glass element 21c (see also [reference]) can be used between terminal 41 and terminal via 21b. Figure 2 This seals and fixes the components. This not only reduces stress caused by temperature changes but also improves the seal between terminal 41 and substrate 21.

[0032] In this embodiment, a meandering groove is formed on the side surface of the base plate 3 closest to the substrate 21. The groove and the adjacent side surface of the base plate 3 form the aforementioned meandering channel 30. In other embodiments, the meandering channel 30 may also be formed by the aforementioned groove on the substrate 21 and another groove formed on the bottom surface of the substrate 21.

[0033] The substrate 21 may be provided with a clearance hole 22d to allow space for the pressure-sensitive element 20. The clearance hole 22d has a stepped surface facing away from the base plate 3. A first circuit is provided on the surface of the substrate 21 away from the base plate 3. A second circuit electrically connected to the first circuit is provided on the stepped surface. The pressure-sensitive element 20 is electrically connected to the second circuit via a lead 20a. The clearance hole 22d is filled with a protective gel covering the pressure-sensitive element 20 and the lead 20a. The tip 41a of the terminal 41 can pass upward through the hole 22a provided on the circuit board 22 and be soldered to the hole 22a to electrically connect to the first circuit. The first circuit and the second circuit can be electrically connected through a via structure provided inside the circuit board 22.

[0034] Please see Figure 2 In the second embodiment, preferably, the base plate 3 extends towards the pressure inlet channel 130 to form a retaining tube 3b. A portion of the terminal 41 is accommodated within the retaining tube 3b. This prevents deformation of the terminal 41 in some cases and improves operability during installation. The bottom surface of the base plate 3 can be fixedly sealed to one end of the inner side of the pressure inlet channel 130 with a sealant adhesive.

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

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

[0037] The scope of this disclosure is not limited by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be included in this disclosure.

Claims

1. A temperature and pressure sensor, characterized in that, include: The housing (1) has an internal mounting cavity (10) and an internal pressure introduction channel (130) connected to the mounting cavity (10) to introduce the medium to be measured; The seat plate (3) is set in the mounting cavity (10) and sealed and fixed to one end of the pressure introduction channel (130); The pressure measuring assembly (2) disposed in the mounting cavity (10) includes a base plate (21) fixed to the side of the base plate (3) away from the pressure inlet channel (130) and having a pressure through hole (21a), a pressure sensitive element (20) sealed and fixed to the pressure through hole (21a) away from the end of the base plate (3), and a circuit board (22) disposed on the side of the base plate (21) away from the pressure inlet channel (130); the base plate (3) and the base plate (21) form a tortuous channel (30), one end of the tortuous channel (30) is connected to the pressure inlet channel (130) away from the pressure measuring assembly (2) through a connecting hole (30a) disposed on the base plate (3), and the other end is connected to the other end of the pressure through hole (21a); A temperature-sensitive element (4) is disposed in the pressure introduction channel (130) and is connected to a terminal (41). The terminal (41) passes through the base plate (3) and the substrate (21) from the outside to the inside and is electrically connected to the circuit board (22). The base plate (3) has a zigzag groove on the side surface near the substrate (21), and the groove and the adjacent side surface of the base plate (3) form a zigzag channel (30); the side surface of the base plate (3) facing the substrate (21) is recessed inward to form a ring of adhesive groove (30e) surrounding the groove; the side surface of the base plate (3) facing the substrate (21) extends outward to form a ring of positioning flange (30d) including the adhesive groove (30e) for positioning the substrate (21).

2. The temperature and pressure sensor according to claim 1, characterized in that, The terminal (41) is fixed to 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 terminal through hole provided on the base plate (3), and the terminal (41) and the terminal through hole are sealed with sealant.

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

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

6. The temperature and pressure sensor according to claim 1, characterized in that, The substrate (21) is provided with a clearance hole (22d) for the pressure-sensitive element (20), the clearance hole (22d) having a stepped surface facing away from the seat plate (3); a first circuit is provided on the surface of the substrate (21) away from the seat plate (3), a second circuit electrically connected to the first circuit is provided on the stepped surface, the pressure-sensitive element (20) is electrically connected to the second circuit through 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).

7. The temperature and pressure sensor according to claim 1, characterized in that, The housing (1) is provided with a vent (11d), and the inner and outer sides of the vent (11d) are covered with a waterproof and breathable membrane (6).

Images