Pressure measuring assembly and pressure sensor
By adopting technologies such as multi-layer sealing structure and sintered glass, the problem of insufficient sealing of pressure sensors in vacuum environments is solved, and the accuracy and stability of measurement are improved.
Patent Information
- Application Number
- CN202323572473.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-26
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2033-12-26
AI Technical Summary
Existing pressure sensors are insufficiently sealed in vacuum environments, resulting in measurement errors and zero-point drift problems, especially the limited effect of hydrogen absorbing materials at low pressures.
A pressure measurement assembly is designed, adopting a multi-layer sealing structure, including substrate, pressure sensitive components, processing circuits, first sealing cover and second sealing cover. The sealing performance is improved by sintering materials such as glass and sealant to ensure the vacuum cavity. Sealing.
The sealing of the pressure sensor is significantly improved, especially under vacuum conditions, reducing measurement errors and zero-point drifts, and enhancing measurement accuracy.
Smart Images
Figure CN222364682U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of sensor technology, and in particular to a pressure measurement component and a pressure sensor. Background Art
[0002] Pressure sensors are sensors used to measure the pressure of the environment or medium. Currently, they are mostly implemented through MEMS (micro-electromechanical systems), that is, pressure is measured through the piezoresistive effect of semiconductors. Among them, the middle part of the silicon core is set to be a diaphragm. The pressure applied to the silicon diaphragm on both sides causes the resistance value of the doped resistor on the silicon diaphragm to change. The current or voltage signal output by the measurement circuit composed of several resistors can be further processed by the conditioning circuit and then output to the outside. When a vacuum cavity is set on one side of the diaphragm in the silicon chip, the measured pressure is the pressure applied on the other side relative to the vacuum, that is, the absolute pressure; when atmospheric pressure is introduced on one side of the diaphragm, the measured pressure is the pressure relative to the atmosphere, that is, the gauge pressure; when other pressures are introduced on both sides of the diaphragm, the measured pressure is the difference between the pressures on both sides, that is, the differential pressure. In some other sensors, temperature sensitive elements can also be integrated to measure the pressure and temperature of the medium at the same time.
[0003] For absolute pressure sensors, the vacuum chamber surrounded by the silicon cover on the other side is not strictly vacuum due to the poor sealing of the bonding process, which can easily lead to measurement errors. In addition, the penetration of various process gases (such as hydrogen) into the silicon material during the production of the silicon wafer will cause zero drift during use. In some known technologies, some film-like hydrogen absorbing materials are arranged inside the vacuum chamber of the silicon cover to absorb part of the hydrogen. However, at low pressure close to vacuum, the effect of hydrogen absorbing materials is still limited.
[0004] The statements in this section merely provide background information related to the present application and may not constitute prior art. Utility Model Content
[0005] In view of the deficiencies of the prior art, the present application provides a pressure measurement assembly and a pressure sensor to improve their sealing performance, especially the vacuum degree of the reference vacuum.
[0006] To achieve the above objectives, the present application provides the following technical solutions: a pressure measurement component, comprising:
[0007] A substrate having pressure holes extending through both sides of the substrate in a thickness direction;
[0008] A pressure sensitive element fixed to the front side of the substrate and sealing the pressure hole;
[0009] A processing circuit is disposed on the front side of the substrate and is electrically connected to the pressure sensitive element;
[0010] A first sealing cover is sealingly connected to one side of the substrate, and the first sealing cover and the substrate form a first sealing cavity for accommodating the pressure sensitive element and the processing circuit;
[0011] A second sealing cover is sealingly connected to one side of the substrate, and the second sealing cover and the substrate form a second sealing cavity for accommodating the first sealing cover;
[0012] and a plurality of relay terminals, one inner end of which is electrically connected to the processing circuit, and one outer end of which is sealed toward the front side and penetrates through the via holes provided on the first sealing cover and the second sealing cover.
[0013] Preferably, it also includes a relay terminal, one end of which is electrically connected to the processing circuit; the other end of the relay terminal sealably passes through the first sealing cover and the second sealing cover toward the front side, or sealably passes through the substrate toward the back side.
[0014] Preferably, the via hole of the first sealing cover extends toward the front side to form a first surrounding wall, and the via hole of the second sealing cover forms a second surrounding wall toward the reverse side. The second surrounding wall and the first surrounding wall are coaxially arranged with a gap between them, and the gap between the relay terminal and the first surrounding wall and the gap between the second surrounding wall and the first surrounding wall are sealed and filled with sintered glass; the inner end of the relay terminal is electrically connected to the processing circuit through an electrical connector.
[0015] Preferably, the electrical connection member is an elastic member, and one end of the electrical connection member close to the processing circuit is electrically connected to the processing circuit by contact.
[0016] Preferably, the electrical connector is a spring or a spring sheet, and one end of the spring sheet away from the processing circuit is fixed to an inner end of the relay terminal.
[0017] Preferably, the substrate, the first sealing cover and the second sealing cover are all made of metal materials, and the first sealing cover and the second sealing cover are both welded to the substrate.
[0018] Preferably, the substrate is made of ceramic material, the first sealing cover and the second sealing cover are both made of metal material, and the first sealing cover and the second sealing cover are welded to two metal plated rings on the substrate in a one-to-one correspondence.
[0019] Preferably, the substrate is made of ceramic material, the first sealing cover and the second sealing cover are both made of glass, and the first sealing cover and the second sealing cover are both fused to the substrate through glass frit.
[0020] Preferably, a connection between the first sealing cover and the substrate is covered with a sealant, and / or a connection between the second sealing cover and the substrate is covered with a sealant.
[0021] The present application also claims protection for a pressure sensor, which includes: the above-mentioned pressure measuring component; a housing having a pressure-inducing channel connected to at least a pressure-sensitive element, the substrate being sealed at an inner end of the pressure-inducing channel; and a terminal fixed to the housing, an inner end of which is electrically connected to an outer end of a relay terminal. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 A schematic diagram of the structure of a pressure sensor according to a first embodiment of the present application;
[0023] Figure 2 This is a schematic structural diagram of a pressure measurement assembly according to a first embodiment of the present application;
[0024] Figure 3 This is a schematic structural diagram of a pressure measurement assembly according to a second embodiment of the present application;
[0025] Figure 4 A schematic structural diagram of a pressure sensor according to a third embodiment of the present application;
[0026] Figure 5 This is a schematic structural diagram of a pressure measurement assembly according to a third embodiment of the present application;
[0027] Explanation of reference numerals: 100, pressure sensor; 110, pressure interface; 111, thin-walled portion; 112, pressing edge; 113, sealing groove; 114, pressure-inducing channel; 11, first shell; 120, electrical connector; 121, step surface; 12, second shell; 13, terminal; 140, pressure sensitive element; 141, substrate; 142, circuit board; 143, first lead; 144, other electronic components; 145, first sealing cover; 146, second sealing cover; 147, relay terminal; 148a, annular positioning portion; 148, sintered glass; 149, second electrical connector; 14a, pressure hole; 14b, thickened flange; 14c, concave cavity; 14d, second surrounding wall; 14e, first surrounding wall; 14, pressure measurement assembly; 15, first electrical connector; 19a, first sealing ring; 19b , second sealing ring; 19c, gasket; 200, pressure sensor; 210, pressure interface; 214, pressure channel; 21, first shell; 220, electrical connector; 20, second shell; 23, terminal; 240, pressure sensitive element; 241, substrate; 242, circuit board; 243, first lead; 244, other electronic components; 245, first sealing cover; 246, second sealing cover; 247, relay terminal; 248, fritted glass; 249, second electrical connector; 24a, pressure hole; 24, pressure measuring assembly; 25, first electrical connector; 29a, first sealing ring; 21a, first glue groove; 20a, flange; 21b, first adhesive sealant; 21d, second glue groove; 26, second adhesive sealant; 21c, third glue groove; 23a, one end; 23b, the other end; DETAILED DESCRIPTION
[0028] 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.
[0029] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present application are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0030] 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.
[0031] 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.
[0032] Please refer to Figure 1 to Figure 2 . The pressure measurement assembly 14 of this embodiment mainly includes a substrate 141, a pressure sensitive element 140, a processing circuit (not marked), a first sealing cover 145 and a second sealing cover 146. Among them, the substrate 141 is provided with pressure holes 14a that penetrate the front and back sides of the substrate 141 in the thickness direction (up and down direction in the figure). The pressure sensitive element 140 is fixed to the pressure sensitive element 140 on the front side of the substrate 141 and seals the pressure hole 14a. The processing circuit is arranged on the front side of the substrate 141, and is electrically connected to the pressure sensitive element 140. The first sealing cover 145 is sealed and connected to the front side of the substrate 141, and it and the substrate 141 form a first sealed cavity for accommodating the pressure sensitive element 140 and the processing circuit. The second sealing cover 146 is sealed and connected to the front side of the substrate 141, and it and the substrate 141 form a second sealed cavity for accommodating the first sealing cover 145. The pressure measurement assembly 14 of this embodiment has high sealing performance, especially when the first sealed cavity and the second sealed cavity are vacuum.
[0033] The pressure measurement assembly 14 of this embodiment may also include a plurality of relay terminals 147 for electrical connection with the outside. An inner end of the relay terminal 147 is electrically connected to the processing circuit, and an outer end thereof is sealedly passed through a via hole (not marked) provided on the first sealing cover 145 and the second sealing cover 146 toward the front side, thereby electrically connecting the processing circuit in the first sealing cover 145 to the outside.
[0034] The processing circuit of this embodiment may be disposed on the front side of a circuit board 142, and the back side of the circuit board 142 is attached and fixed to the front side of the substrate 141. The circuit board 142 may be provided with a notch or window to expose the pressure sensitive element 140 to the lower side of the circuit board 142, and the pressure sensitive element 140 is electrically connected to the processing circuit through the first lead 143. The processing circuit may also include other electronic components 144, such as a conditioning chip, etc.
[0035] In some other schemes, preferably, the via hole of the first sealing cover 145 extends toward the front side to form a first surrounding wall 14e. The via hole of the second sealing cover 146 is formed with a second surrounding wall 14d toward the reverse side. The second surrounding wall 14d and the first surrounding wall 14e are coaxially sleeved and a gap is left between the two. The gap between the relay terminal 147 and the first surrounding wall 14e and the gap between the second surrounding wall 14d and the first surrounding wall 14e are sealed and filled with sintered glass. The inner end of the relay terminal 147 is electrically connected to the processing circuit through the first electrical connector 149. In this way, a reliable seal can be formed between the first sealing cover 145 and the second sealing cover 146 at the same time through the sintered glass.
[0036] The first electrical connector 149 is preferably an elastic member, and its end close to the processing circuit is electrically connected to the processing circuit by contact. Further, the first electrical connector 149 is a spring or a spring sheet, and the end of the spring away from the processing circuit can be welded, sleeved or otherwise fixed to the inner end of the relay terminal 147, and the end of the spring away from the processing circuit can be welded, integrally connected or otherwise fixed to the inner end of the relay terminal 147.
[0037] Preferably, the substrate 141, the first sealing cover 145 and the second sealing cover 146 are all made of metal materials. The first sealing cover 145 and the second sealing cover 146 are both welded to the substrate 141; or, the substrate 141 is made of ceramic material, the first sealing cover 145 and the second sealing cover 146 are both made of metal material, and the first sealing cover 145 and the second sealing cover 146 are welded to two metal plated rings on the substrate 141 (which can be attached to the surface of the substrate 141 by vacuum plating or other coating techniques) one by one; or, the substrate 141 is made of ceramic material, the first sealing cover 145 and the second sealing cover 146 are both made of glass, and the first sealing cover 145 and the second sealing cover 146 are both fused to the substrate 141 by glass frit. When the first sealing cover 145 and the second sealing cover 146 are both made of metal materials, they can also play the role of electromagnetic shielding to prevent external electromagnetic fields from interfering with the measurement signal.
[0038] In some other solutions, preferably, the connection between the first sealing cover 145 and the substrate 141 is covered with a sealant (not shown), and / or the connection between the second sealing cover 146 and the substrate 141 is covered with a sealant (not marked), which can further improve the sealing performance.
[0039] The first sealed cavity formed by the first sealing cover 145 and the substrate 141 is preferably vacuum, and the pressure sensitive element 140 can be an absolute pressure chip or a differential pressure chip. The second sealed cavity formed by the second sealing cover 146 and the substrate 141 can also be vacuum.
[0040] The pressure sensor 100 of this embodiment includes the above-mentioned pressure measurement component 14, and also includes a shell for accommodating the above-mentioned pressure measurement component 14. The shell includes a first shell 11 and a second shell 12. The first shell 11 has a pressure-inducing channel 114 for introducing pressure. One end of the inner side of the pressure-inducing channel 114 is connected to the pressure sensitive element 140 to apply the pressure or pressure medium to be measured to the pressure sensitive element 140. The substrate 141 is blocked at the inner end of the pressure-inducing channel 114 to isolate other components from the pressure or pressure medium to be measured. The pressure sensor 100 also includes a terminal 13 fixed on the second shell 12, and one end of the inner side thereof is electrically connected to the outer end of the relay terminal 147 through the first electrical connector 15. The pressure-inducing channel 114 is arranged in a pressure interface 110 formed at the lower end of the first shell 11, and the pressure interface 110 is used for connection with a container containing a pressure medium.
[0041] Preferably, the front side of the pressure sensitive element 140 is arranged upward. The second shell 12 is located at one end of the upper side of the first shell 11. The upper part of the second shell 12 forms an electrical connector 120 for connecting to an external device, and the terminal 13 is fixed to the second shell 12, and its upper end extends into the electrical connector 120, and its lower end is downwardly sealed to penetrate the electrical connector 120, and is electrically connected to the relay terminal 147 through the first electrical connector 15. Among them, the first electrical connector 15 can be a flexible member, such as a flexible board. The upper end of the first shell 11 can form a circle of thin-walled portion 111, and the upper end of the thin-walled portion 111 is rolled inward to form a pressing edge 112, and the pressing edge 112 is pressed downward on the upward step surface 121 formed at the lower part of the second shell 12, and the lower end edge of the second shell 12 is pressed downward against the edge of the substrate 141, and the substrate 141 and the first shell 11 are sealed by the second sealing ring 19b. A groove (not marked) is formed on the outside of the first housing 11, and a first sealing ring 19a is arranged in the groove to facilitate sealing with a container containing a pressure medium. The second sealing ring 19b is arranged in a sealing groove 113 formed on the end surface of the pressure channel 114 facing the pressure measuring component 14.
[0042] During production, the relay terminal 147 and the first sealing cover 145 can be first fixed together by melted glass material (forming sintered glass 148); then the edge of the first sealing cover 145 is sealedly welded to the concave cavity 14c formed by the inward depression on the front side of the substrate 141 by laser welding or other methods (the periphery of the concave cavity 14c relatively forms an upward circle of thickened flange 14b); then a circle of annular positioning portion 148a formed on the second sealing cover 146 is sleeved on the opening of the thickened flange 14b to position the two, and the edge of the annular positioning portion 148a is welded to the front side of the substrate 141; finally, part of the glass material is refilled between the relay terminal 147 and the second surrounding wall 14d and melted to form another part of sintered glass 148.
[0043] Preferably, the bottom of the second shell 12 and the inner side of the thin-walled portion 111 of the first shell 11 are sealed by a gasket 19 c .
[0044] See also Figure 3 Compared with the first embodiment, the edge of the second sealing cover 146 of the pressure measurement assembly 14 of the second embodiment of the present application extends to the side of the substrate 141 and is sealed to the side of the substrate 141. In this case, the substrate 141, the first sealing cover 145 and the second sealing cover 146 are preferably all circular. In some other schemes, the edge of the first sealing cover 145 can also extend to the side of the substrate 141 and be sealed to the side of the substrate 141.
[0045] Please refer to Figure 4 , Figure 5 . The pressure measurement assembly 24 of this embodiment mainly includes a substrate 241, a pressure sensitive element 240, a processing circuit (not marked), a first sealing cover 245 and a second sealing cover 246. Among them, the substrate 241 is provided with pressure holes 24a that penetrate the front and back sides of the substrate 241 in the thickness direction (up and down direction in the figure). The pressure sensitive element 240 is fixed to the pressure sensitive element 240 on the front side of the substrate 241 and seals the pressure hole 24a. The processing circuit is arranged on the front side of the substrate 241, and is electrically connected to the pressure sensitive element 240. The first sealing cover 245 is sealed and connected to the front side of the substrate 241, and it and the substrate 241 form a first sealed cavity for accommodating the pressure sensitive element 240 and the processing circuit. The second sealing cover 246 is sealed and connected to the front side of the substrate 241, and it and the substrate 241 form a second sealed cavity for accommodating the first sealing cover 245. The pressure measurement assembly 24 of this embodiment has high sealing performance, especially when the first sealed cavity and the second sealed cavity are vacuum.
[0046] The pressure measurement assembly 24 of this embodiment further includes a plurality of relay terminals 247 for electrical connection with the outside. An inner end of the relay terminal 247 is electrically connected to the processing circuit, and an outer end thereof is sealedly penetrated through a via hole (not marked) opened on the substrate 241 toward the reverse side, and a fritted glass 248 may be provided in the via hole to seal the relay terminal 247 and the substrate 241, thereby electrically connecting the processing circuit in the first sealing cover 245 to the outside.
[0047] The processing circuit of this embodiment can be arranged on the front side of the substrate 241, and the substrate 241 can be made of insulating materials such as ceramics, or the substrate 241 is made of conductive materials such as metals and its processing circuit is arranged on an insulating layer arranged on the front side of the substrate 241. The pressure sensitive element 240 is electrically connected to the processing circuit through the first lead 243. The circuit board 242 may also include other electronic components 244, such as a conditioning chip, etc.
[0048] The inner end of the relay terminal 247 is electrically connected to the processing circuit via the first electrical connector 249. The first electrical connector 249 may be a lead wire, and the two ends of the lead wire are electrically connected to the inner end of the relay terminal 247 and the processing circuit, respectively.
[0049] Preferably, the substrate 241, the first sealing cover 245 and the second sealing cover 246 are all made of metal materials. The first sealing cover 245 and the second sealing cover 246 are both welded to the substrate 241; or, the substrate 241 is made of ceramic material, the first sealing cover 245 and the second sealing cover 246 are both made of metal materials, and the first sealing cover 245 and the second sealing cover 246 are welded to two metal plated rings on the substrate 241 (which can be attached to the surface of the substrate 241 by vacuum plating or other coating techniques) one by one; or, the substrate 241 is made of ceramic material, the first sealing cover 245 and the second sealing cover 246 are both made of glass, and the first sealing cover 245 and the second sealing cover 246 are both welded to the substrate 241 by glass frit.
[0050] In some other solutions, preferably, the connection between the first sealing cover 245 and the substrate 241 is covered with a sealant (not shown), and / or the connection between the second sealing cover 246 and the substrate 241 is covered with a sealant (not marked), which can further improve the sealing performance.
[0051] The first sealed cavity formed by the first sealing cover 245 and the substrate 241 is preferably vacuum, and the pressure sensitive element 240 can be an absolute pressure chip or a differential pressure chip. The second sealed cavity formed by the second sealing cover 246 and the substrate 241 can also be vacuum.
[0052] The pressure sensor 200 of this embodiment includes the pressure measuring assembly 24 mentioned above, and also includes a shell for accommodating the pressure measuring assembly 24. The shell includes a first shell 21 and a second shell 20. The first shell 21 has a pressure channel 214 for introducing pressure. One end of the inner side of the pressure channel 214 is sealed to the pressure sensitive element 240 to apply the pressure or pressure medium to be measured to the pressure sensitive element 240. The substrate 241 is blocked at one end of the inner side of the pressure channel 214 to isolate other elements from the pressure or pressure medium to be measured. The second shell 20 is bonded to an opening on the first shell 21 from the front side. For example, the second shell 20 can be directly bonded and sealed around the above opening of the first shell 21, or further, the above opening of the first shell 21 is concave downward to form a circle of first glue groove 21a, and accordingly, the edge of the second shell 20 protrudes downward to form a circle of flange 20a. After the flange 20a is inserted into the first glue groove 21a, the flange 20a is filled with the first adhesive sealant 21b.
[0053] One end of the pressure-inducing channel 214 is sealedly connected to the pressure-sensitive element 240 to apply the pressure of the medium to be measured to the pressure-sensitive element 240 through the pressure hole 24a on the substrate 241. For example, a second glue groove 21d is provided on the surface of one end of the pressure-inducing channel 214 facing the pressure measuring component 14. The second housing 12 is sealed and bonded to the reverse side of the substrate 241 by the second adhesive sealant 26 filled in the second glue groove 21d.
[0054] The pressure sensor 200 may also include a terminal 23 fixed to the housing, one inner end of which is electrically connected to the outer end of the relay terminal 247. The pressure-inducing channel 214 is arranged in a pressure interface 210 formed at the lower end of the first shell 21, and the pressure interface 210 is used for connection with a container containing a pressure medium. The relay terminal 247 is located outside the second glue groove 21d. The relay terminal 247 may be L-shaped, including a long arm and a short arm connected vertically, the short arm extending up and down and sealed with a via on the substrate 241 through a sintered glass 248, and the upper end of the short arm is electrically connected to the processing circuit through a second electrical connector 249; one end 23a of the long arm away from the short arm extends horizontally in a direction away from the second glue groove 21d, and the other end 23b thereof is electrically connected through a first electrical connector 25 (such as an aluminum wire, an aluminum sheet, etc.).
[0055] Preferably, the front side of the pressure sensitive element 240 is arranged upward. The first housing 21 is formed with an electrical connector 220 extending parallel to the substrate 241 for connecting with an external device. The terminal 23 is fixed on the second housing 20, one end of which extends into the electrical connector 220, and the other end of which is sealed inwardly through the electrical connector 220 and is electrically connected to the relay terminal 247 through the first electrical connector 25. The first electrical connector 25 can be a flexible member, such as a flexible board.
[0056] A groove (not marked) is formed on the outside of the first housing 21, and a first sealing ring 29a is disposed in the groove to facilitate sealing with a container containing a pressure medium. A third glue groove 21c facing upwardly and directly opposite to the first electrical connector 25 can be disposed on the first housing 21, and the third glue groove 21c is filled with protective glue, which covers the other end 23b and / or the first electrical connector 25.
[0057] When manufacturing the pressure measurement component 24, the relay terminal 247 and the substrate 241 can be first fixed together by melted glass material (forming sintered glass 248), and the relay terminal 247 can be electrically connected to the processing circuit through the first electrical connector 25; then the edge of the first sealing cover 245 is sealedly welded to the front side of the substrate 241 by laser welding or the like; and then the second sealing cover 246 is welded to the front side of the substrate 241.
[0058] When the sealing cavity is vacuum, the sealing operation can be performed in a vacuum chamber environment.
[0059] The scope of the disclosure is defined not by the detailed description but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are construed as being included in the disclosure.
Claims
1. A pressure measurement assembly (14, 24), characterized in that: include: A base plate (141, 241) is provided with pressure holes (14a, 24a) penetrating the base plate on both sides in the thickness direction; A pressure sensitive element (140, 240) fixed to the front side of the substrate (141, 241) and sealing the pressure hole (14a, 24a); A processing circuit disposed on the front side of the substrate (141, 241) and electrically connected to the pressure sensitive element (140, 240); A first sealing cover (145, 245) is sealingly connected to one side of the substrate (141, 241), and the first sealing cover and the substrate (141, 241) form a first sealing cavity for accommodating a pressure sensitive element (140, 240) and a processing circuit; A second sealing cover (146, 246) is sealingly connected to one side of the substrate (141, 241), and together with the substrate (141, 241) forms a second sealing cavity for accommodating the first sealing cover (145, 245); and a plurality of relay terminals (147, 247), one inner end of which is electrically connected to the processing circuit, and one outer end of which is sealedly penetrated through the via holes provided on the first sealing cover (145, 245) and the second sealing cover (146, 246) toward the front side.
2. The pressure measuring assembly (14, 24) according to claim 1, characterized in that It also includes a relay terminal (147, 247), one end of which is electrically connected to the processing circuit; the other end of the relay terminal (147, 247) is sealed through the first sealing cover (145, 245) and the second sealing cover (146, 246) toward the front side, or is sealed through the substrate (141, 241) toward the back side.
3. The pressure measuring assembly (14) according to claim 1, characterized in that The through hole of the first sealing cover (145) extends toward the front side to form a first surrounding wall (14e), and the through hole of the second sealing cover (146) forms a second surrounding wall (14d) toward the reverse side. The second surrounding wall (14d) and the first surrounding wall (14e) are coaxially sleeved with a gap therebetween. The gap between the relay terminal (147) and the first surrounding wall (14e) and the gap between the second surrounding wall (14d) and the first surrounding wall (14e) are sealed and filled with sintered glass (148); the inner end of the relay terminal (147, 247) is electrically connected to the processing circuit through an electrical connector.
4. The pressure measuring assembly (14, 24) according to claim 3, characterized in that The electrical connection member is an elastic member, and one end of the elastic member close to the processing circuit is electrically connected to the processing circuit by contact.
5. The pressure measuring assembly (14, 24) according to claim 4, characterized in that The electrical connection piece is a spring or a spring sheet, and one end of the spring sheet away from the processing circuit is fixed to the inner end of the relay terminal (147, 247).
6. The pressure measuring assembly (14, 24) according to claim 1, characterized in that The base plate (141, 241), the first sealing cover (145, 245) and the second sealing cover (146, 246) are all made of metal materials, and the first sealing cover (145, 245) and the second sealing cover (146, 246) are both welded to the base plate (141, 241).
7. The pressure measuring assembly (14, 24) according to claim 1, characterized in that The substrate (141, 241) is made of ceramic material, the first sealing cover (145, 245) and the second sealing cover (146, 246) are both made of metal material, and the first sealing cover (145, 245) and the second sealing cover (146, 246) are welded to two metal plated rings on the substrate (141, 241) in a one-to-one correspondence.
8. The pressure measuring assembly (14, 24) according to claim 1, characterized in that The substrate (141, 241) is made of ceramic material, the first sealing cover (145, 245) and the second sealing cover (146, 246) are both made of glass, and the first sealing cover (145, 245) and the second sealing cover (146, 246) are both fused to the substrate (141, 241) through glass frit.
9. The pressure measuring assembly (14, 24) according to claim 1, characterized in that The connection between the first sealing cover (145, 245) and the substrate (141, 241) is covered with sealant, and / or the connection between the second sealing cover (146, 246) and the substrate (141, 241) is covered with sealant.
10. A pressure sensor, characterized in that: include: The pressure measuring assembly according to any one of claims 1 to 8; The housing has a pressure-inducing channel (114, 214) at least connected to a pressure-sensitive element (140, 240), and the substrate (141, 241) is sealed at one end of the inner side of the pressure-inducing channel (114, 214); and a terminal (13, 23) fixed on the housing, wherein an inner end thereof is electrically connected to an outer end of the relay terminal (147, 247).