Novel vehicle micro-melting high-pressure sensor and manufacturing method thereof

Abstract

The invention discloses a novel vehicle micro-melting high-pressure sensor and a manufacturing method, and relates to the technical field of pressure sensors, the novel vehicle micro-melting high-pressure sensor comprises a plastic connector, a metal shell, a pressure sensing element, a first circuit board, a second circuit board, a flexible connecting plate, a spring, a spring seat and a supporting ring; the pressure sensing element is arranged at the pressure bearing end of a containing cavity formed by the metal shell and the plastic connector; the first circuit board is electrically connected with the second circuit board through a flexible connecting plate; the supporting ring is arranged between the second circuit board and the pressure sensing element; the spring seat is arranged between the first circuit board and the second circuit board, the first circuit board is fixed with the spring seat through hot riveting or glue, one end of the spring is electrically connected with the first circuit board, and the other end of the spring is electrically connected with an external port; the metal shell and the pressure sensing element are packaged through laser ring welding; therefore, the vehicle micro-melting high-pressure sensor is compact in structure, simplified in electric connection, high in assembly efficiency, good in reliability and suitable for vehicle high-pressure pressure detection.

Description

Technical Field

[0001] This invention relates to the field of pressure sensor technology, and in particular to a novel micro-fuse high-pressure sensor for vehicles and its manufacturing method. Background Technology

[0002] Pressure sensors are one of the key components in vehicle electronic control systems, widely used in braking systems, powertrain systems, and various safety control systems to collect and provide feedback on pressure parameters in real time. In the automotive field, especially in anti-lock braking systems (ABS), electronic stability control (ESC), and electromechanical braking systems (EMB), high demands are placed on the response speed, measurement accuracy, reliability, and environmental adaptability of pressure sensors.

[0003] Existing automotive high-pressure sensors typically employ metal diaphragms as both the pressure-bearing and pressure-sensing structure. Strain gauges are formed on the diaphragm or substrate using glass micro-fusion or thin-film sputtering processes to convert pressure signals into electrical signals. Compared to silicon piezoresistive sensors, micro-fused high-pressure sensors offer advantages such as high pressure resistance, corrosion resistance, and good long-term stability, making them widely used in automotive high-pressure measurement scenarios. In some industrial applications, however, oil-filled, isolated sensor cores are often used to adapt to more complex operating conditions.

[0004] With the rapid development of automotive electrification, intelligentization, and autonomous driving technologies, the integration of vehicle systems is constantly improving, placing higher demands on the miniaturization, modularization, and high reliability of sensors. Existing automotive micro-fuse high-voltage sensors typically arrange the sensor core, circuit board, and external electrical connection structure separately. The external electrical connections of the sensor generally adopt the form of spring contacts, pins, or terminals to realize the lead-out of electrical signals and the connection with the vehicle wiring harness.

[0005] However, the aforementioned electrical connection methods still have certain limitations in practical applications. On the one hand, spring contact and terminal connection structures occupy a large amount of space in the axial or radial direction, which is not conducive to further compaction of the overall sensor structure and limits its application in braking systems or integrated modules where installation space is limited. On the other hand, multi-layer connection structures and contact interfaces increase assembly processes and manufacturing complexity, which not only affects production efficiency but also poses challenges to connection reliability under long-term vibration, thermal cycling, and other automotive operating conditions.

[0006] In summary, the existing technology has at least the following technical problems: Existing automotive micro-fuse high-voltage sensors suffer from technical problems such as large space occupation of circuit structure, complex electrical connection structure, and limited assembly efficiency and long-term reliability. Summary of the Invention

[0007] The purpose of this invention is to provide a novel micro-fuse high-voltage sensor for vehicles and its manufacturing method, so as to solve the technical problems of existing micro-fuse high-voltage sensors for vehicles, such as large space occupied by circuit structure, complex electrical connection structure, and limited assembly efficiency and long-term reliability.

[0008] The preferred technical solutions among the many technical solutions provided by this invention can produce a variety of technical effects, which are described in detail below.

[0009] To address the aforementioned technical problems, the present invention provides the following technical solution: This invention provides a novel automotive micro-fuse high-voltage sensor, comprising a plastic connector, a metal housing, a pressure-sensing element, a first circuit board, a second circuit board, a flexible connecting plate, a spring, a spring seat, and a support ring. The metal housing is connected to the plastic connector to form a receiving cavity, and the pressure-sensing element is disposed at the pressure-bearing end of the receiving cavity. The first circuit board and the second circuit board are electrically connected through the flexible connecting plate to form a rigid-flex circuit structure. The support ring is disposed between the second circuit board and the pressure-sensing element, and the support ring and the second circuit board are fixed by surface mounting and reflow soldering. The bottom outer ring of the support ring is connected to the stepped surface of the pressure-sensing element through three points. The spring seat is fixed by welding; it is located between the first circuit board and the second circuit board, and the first circuit board and the spring seat are fixed by hot riveting or glue; one end of the spring is inserted into the inner cavity of the plastic connector and passes through the first circuit board, and the other end is electrically connected to the external port; the bottom outer circle of the metal shell and the stepped surface of the pressure sensing element are encapsulated by laser ring welding; and the electrical signal output by the pressure sensing element is transmitted to the second circuit board via a binding wire, and the second circuit board transmits the signal to the first circuit board via the flexible connecting plate. The first circuit board is electrically connected to the spring through the first surface pad, and the spring transmits the electrical signal to the external port.

[0010] In one embodiment, the pressure-sensing element includes a stainless steel housing, glass adhesive, and a strain gauge, wherein the strain gauge is fixed to the surface of the stainless steel housing facing the second circuit board using the glass adhesive as an adhesive carrier.

[0011] In one embodiment, the metal housing is fixedly connected to the plastic connector by injection molding and / or riveting.

[0012] In one embodiment, the support ring is configured to provide radial positioning and / or axial restraint for the second circuit board to reduce relative displacement under vehicle vibration and thermal cycling conditions.

[0013] In one embodiment, the three-point welding is any one or more of resistance spot welding, laser spot welding, or arc spot welding; the laser ring welding is continuous ring welding or segmented ring welding.

[0014] In one embodiment, the surface of the second circuit board is printed with metal circuits and second surface pads, and resistors and / or capacitors are mounted on the metal circuits and pads.

[0015] In one embodiment, the pressure-sensing element is electrically connected to the second surface pad via the binding wire.

[0016] In one embodiment, the first circuit board is provided with a signal conditioning chip for amplifying, filtering and / or compensating for temperature drift of the output signal of the pressure sensing element; the signal conditioning chip is arranged toward the cavity of the spring seat.

[0017] In one embodiment, the two ends of the flexible connecting plate are respectively fixedly connected to the first circuit board and the second circuit board by welding and / or connector insertion.

[0018] A method for manufacturing a micro-fused high-voltage sensor for vehicles is also provided. The method for manufacturing a micro-fused high-voltage sensor for vehicles includes the following steps: S1, forming a receiving cavity: fixing a metal shell and a plastic connector together to form a receiving cavity; S2. Second circuit board connection: The pressure sensing element is inserted into the support ring, and the pressure sensing element is connected to the second surface pad of the second circuit board via a binding wire. The second circuit board is connected to the first circuit board via a flexible connecting plate. S3. Fixing the support ring to the second circuit board: Fix the support ring to the second circuit board by mounting and reflow soldering; S4. Fixing the support ring to the pressure sensing element: Fix the bottom outer ring of the support ring to the stepped surface of the pressure sensing element by welding at three points; S5. First circuit board connection: After fixing the first circuit board and the spring seat with hot riveting or glue, install them into the receiving cavity, and install the spring into the inner cavity of the plastic connector and pass it through to the first surface pad of the first circuit board. The first surface pad is electrically connected to the spring. S6. Packaging: After assembly, laser welding is performed on the bottom outer circle of the metal casing and the stepped surface of the pressure sensing element to achieve packaging.

[0019] The beneficial effects of this invention are as follows: (1) Significantly reduces the space occupied by the circuit structure and improves the structural compactness. This technical solution electrically connects the first circuit board and the second circuit board using a flexible connecting plate to form a circuit structure that combines rigid and flexible boards. This allows the circuit boards to be arranged in layers along the sensor axis, effectively avoiding the occupation of radial and axial space by traditional single rigid circuit boards or parallel arrangement structures. This significantly improves the compactness of the overall sensor structure and is suitable for high-voltage automotive applications where installation space is limited.

[0020] (2) Simplify the electrical connection structure, reduce connection layers, and improve connection reliability. This technical solution sets the spring as part of the internal electrical signal transmission path. The spring is directly electrically connected to the first surface pad of the first circuit board, and the spring leads the electrical signal to the external port. This avoids the external spring contact, pin or multi-level terminal structure commonly used in the prior art, reduces the number of electrical connection interfaces and structural complexity, thereby reducing the risk of poor contact, loosening and failure, and improving the long-term electrical connection reliability.

[0021] (3) Improve structural stability and consistency through the synergistic application of multiple welding methods. In this technical solution, the support ring and the second circuit board are fixed by surface mounting and reflow soldering, the support ring and the pressure sensing element are fixed by three-point welding, and the metal shell and the pressure sensing element are encapsulated by laser ring welding. Through the synergistic application of multiple welding methods at different structural levels, a stable and reliable metal connection structure is formed in the key stress and sealing parts, which effectively improves the structural stability and sealing reliability of the sensor under automotive working conditions such as vibration, shock and thermal cycling.

[0022] (4) Improve assembly efficiency and adapt to the needs of automated production. This technical solution uses SMT reflow soldering to fix the second circuit board and the support ring, and uses hot riveting or glue to fix the first circuit board and the spring seat. This reduces the traditional manual assembly and complex calibration processes, making the overall sensor assembly process clearer and more controllable. It is conducive to realizing automated or semi-automated production, thereby improving production efficiency and product consistency.

[0023] (5) It helps to improve the long-term reliability and service life of the whole machine. By using the support ring to radially position and axially limit the second circuit board, and the spring seat to structurally support the first circuit board, this technical solution effectively reduces the relative displacement and stress concentration of the circuit board under long-term vehicle vibration and temperature change conditions, further improving the overall vibration resistance and long-term reliability of the sensor.

[0024] In summary, this technical solution effectively solves the technical problems of large circuit space occupation, complex electrical connection structure, and limited assembly efficiency and long-term reliability in existing automotive micro-fuse high-voltage sensors through synergistic optimization of circuit structure, electrical connection method, and assembly and packaging process. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of the automotive micro-fuse high-voltage sensor of the present invention; Figure 2 This is a schematic cross-sectional view of the overall structure of the automotive micro-fuse high-voltage sensor of the present invention; Figure 3 This is a schematic diagram of the rigid-flex PCB combined circuit structure of the present invention; Figure 4 This is a schematic diagram of the assembly structure of the spring, spring seat, flexible and rigid board combined circuit structure, support ring and pressure sensing element of the present invention. Figure 5 This is a schematic diagram of the manufacturing process of the automotive micro-fuse high-voltage sensor of the present invention.

[0027] The accompanying figure is labeled as follows: 1. Plastic connector; 2. Metal outer shell; 21. Receiving cavity; 211. Pressure-bearing end; 3. Pressure sensing element; 31. Stainless steel housing; 32. Strain gauge; 4. Rigid-flex PCB combined circuit structure; 41. First circuit board; 411. First surface pad; 412. Signal conditioning chip; 42. Second circuit board; 421. Second surface pad; 43. Flexible connection board; 5. Spring; 6. Spring seat; 7. Support ring. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0029] The specific embodiment provides a novel automotive micro-fused high-pressure sensor and its manufacturing method, including a plastic connector, a metal housing, a pressure-sensing element, a first circuit board, a second circuit board, a flexible connecting plate, a spring, a spring seat, and a support ring. The pressure-sensing element is located at the pressure-bearing end of the cavity formed by the metal housing and the plastic connector. The first circuit board and the second circuit board are electrically connected by the flexible connecting plate. The support ring is located between the second circuit board and the pressure-sensing element. The spring seat is located between the first circuit board and the second circuit board. The first circuit board is fixed to the spring seat by hot riveting or glue. One end of the spring is electrically connected to the first circuit board, and the other end is electrically connected to an external port. The metal housing and the pressure-sensing element are encapsulated by laser ring welding. This achieves a compact structure, simplified electrical connection, high assembly efficiency, and good reliability, making it suitable for automotive high-pressure detection. It effectively solves the technical problems of existing automotive micro-fused high-pressure sensors, such as large space occupation of circuit structure, complex electrical connection structure, and limited assembly efficiency and long-term reliability.

[0030] The first implementation of a micro-fuse high-voltage sensor for automobiles, for example Figures 1 to 4 As shown, the circuit includes a plastic connector 1, a metal housing 2, a pressure-sensing element 3, a first circuit board 41, a second circuit board 42, a flexible connecting plate 43, a spring 5, a spring seat 6, and a support ring 7. The metal housing 2 is connected to the plastic connector 1 to form a receiving cavity 21, and the pressure-sensing element 3 is located at the pressure-bearing end 211 of the receiving cavity 21. The first circuit board 41 and the second circuit board 42 are electrically connected through the flexible connecting plate 43 to form a rigid-flex circuit structure 4. The support ring 7 is located between the second circuit board 42 and the pressure-sensing element 3, and the support ring 7 is fixed to the second circuit board 42 by mounting and reflow soldering. The bottom outer ring of the support ring 7 is connected to the stepped surface of the pressure-sensing element 3 by three-point welding. The spring seat 6 is located between the first circuit board 41 and the second circuit board 42. The first circuit board 41 and the spring seat 6 are fixed by hot riveting or glue. One end of the spring 5 is inserted into the inner cavity of the plastic connector 1 and passes through the first circuit board 41, while the other end is electrically connected to the external port. The bottom outer circle of the metal shell 2 and the stepped surface of the pressure sensing element 3 are encapsulated by laser ring welding. Furthermore, the electrical signal output by the pressure sensing element 3 is transmitted to the second circuit board 42 via a binding wire. The second circuit board 42 transmits the signal to the first circuit board 41 via a flexible connecting plate 43. The first circuit board 41 is electrically connected to the spring 5 via the first surface pad 411, and the spring 5 transmits the electrical signal to the external port.

[0031] Specifically, addressing the technical problems of existing automotive micro-fuse high-voltage sensors, such as large space occupation of circuit structure, complex electrical connection structure, and limited assembly efficiency and long-term reliability, the automotive micro-fuse high-voltage sensor of this technical solution has the following technical advantages: significantly reducing the space occupation of the circuit structure and improving structural compactness; this technical solution forms a circuit structure combining rigid and flexible boards by electrically connecting the first circuit board 41 and the second circuit board 42 with a flexible connecting plate 43, allowing the circuit boards to be arranged in layers along the sensor axis, effectively avoiding the occupation of radial and axial space by traditional single rigid circuit boards or parallel arrangement structures, thereby significantly improving the overall compactness of the sensor structure, and is suitable for automotive high-voltage application scenarios with limited installation space.

[0032] This technical solution simplifies the electrical connection structure, reduces connection layers, and improves connection reliability. The spring 5 is set as part of the internal electrical signal transmission path. It is directly electrically connected to the spring 5 through the first surface pad 411 of the first circuit board 41, and the spring 5 leads the electrical signal to the external port. This avoids the external spring 5 contact, pin, or multi-level terminal structure commonly used in the prior art, reduces the number of electrical connection interfaces and structural complexity, thereby reducing the risk of poor contact, loosening and failure, and improving the long-term electrical connection reliability.

[0033] By combining multiple welding methods, the structural stability and consistency are improved. In this technical solution, the support ring 7 and the second circuit board 42 are fixed by surface mounting and reflow soldering, the support ring 7 and the pressure sensing element 3 are fixed by three-point welding, and the metal shell 2 and the pressure sensing element 3 are encapsulated by laser ring welding. Through the combined application of multiple welding methods at different structural levels, a stable and reliable metal connection structure is formed in the key stress and sealing parts, which effectively improves the structural stability and sealing reliability of the sensor under automotive working conditions such as vibration, impact and thermal cycling.

[0034] To improve assembly efficiency and meet the needs of automated production, this technical solution uses SMT reflow soldering to fix the second circuit board 42 and the support ring 7, and uses hot riveting or glue to fix the first circuit board 41 and the spring seat 6. This reduces traditional manual assembly and complex calibration processes, making the overall sensor assembly process clearer and more controllable, which is conducive to achieving automated or semi-automated production, thereby improving production efficiency and product consistency.

[0035] This is beneficial to improving the long-term reliability and service life of the whole machine. Through the radial positioning and axial limiting of the second circuit board 42 by the support ring 7 and the structural support of the first circuit board 41 by the spring seat 6, this technical solution effectively reduces the relative displacement and stress concentration of the circuit board under long-term vehicle vibration and temperature change conditions, and further improves the overall vibration resistance and long-term reliability of the sensor.

[0036] In summary, this technical solution effectively addresses the technical problems of existing automotive micro-fuse high-voltage sensors, such as large space occupation of circuit structure, complex electrical connection structure, and limited assembly efficiency and long-term reliability, through synergistic optimization of circuit structure, electrical connection method, and assembly and packaging process.

[0037] As one alternative implementation method: Regarding the specific connection and fixing method between the aforementioned metal casing 2 and the plastic connector 1, this embodiment is as follows: Figure 1 and Figure 2 As shown, the metal casing 2 is fixedly connected to the plastic connector 1 by injection molding and / or riveting processes.

[0038] In application, the metal housing 2 is fixedly connected to the plastic connector 1 by injection molding and / or riveting, forming a stable mechanical connection between the metal housing 2 and the plastic connector 1 in the axial and radial directions. This connection method avoids the structural redundancy and space occupation caused by traditional threaded connections or independent fasteners. On the other hand, the overall structure formed by injection molding or riveting improves the resistance to loosening of the connection part under vibration, impact and temperature change conditions. At the same time, this fixing method, together with the laser ring welding encapsulation structure of the bottom outer circle of the metal housing 2 and the pressure sensing element 3, makes the sensor as a whole form a continuous and reliable force and sealing path, thereby improving the overall structural strength, sealing reliability and long-term stability, and effectively solving the problem of complex housing connection structure and limited reliability in existing automotive micro-fusible high-voltage sensors.

[0039] In other embodiments, the injection molding overlay is a one-time injection molding or two-time injection molding structure; the riveting process can be radial riveting, axial flanging, or partial roll forming.

[0040] In addition, positioning steps, anti-rotation structures, or sealing ribs are provided between the metal shell 2 and the plastic connector 1 to further improve assembly accuracy and sealing performance.

[0041] Regarding the specific function of the aforementioned support ring 7 on the second circuit board 42, this embodiment is as follows: Figure 2 and Figure 4 As shown, the support ring 7 is configured to provide radial positioning and / or axial limiting of the second circuit board 42 to reduce relative displacement under vehicle vibration and thermal cycling conditions.

[0042] In application, by setting a support ring 7 between the second circuit board 42 and the pressure sensing element 3, and by providing radial positioning and / or axial limiting for the second circuit board 42, the second circuit board 42 forms a clear and stable spatial reference position inside the sensor, thereby effectively suppressing the shaking, warping, or relative displacement of the second circuit board 42 under long-term vehicle vibration and thermal cycling conditions. The support ring 7 also serves as a structural transition component between the second circuit board 42 and the pressure sensing element 3, forming a cooperative fixing structure with the reflow soldering connection of the support ring 7 and the second circuit board 42, as well as the three-point welding connection of the support ring 7 and the pressure sensing element 3. This changes the circuit board fixing method from a single electrical connection to a composite fixing method that combines electrical connection and structural connection, thereby significantly improving the installation stability and overall reliability of the circuit board.

[0043] In other embodiments, the support ring 7 is made of metal or high-strength heat-resistant material, and its cross-sectional shape can be annular, stepped, or with a limiting flange structure; and the support ring 7 has both heat dissipation and electromagnetic shielding functions to meet the needs of different application scenarios.

[0044] Regarding the specific welding methods for the above three-point welding and laser ring welding, this implementation is as follows: Figure 1 , Figure 2 and Figure 4 As shown, three-point welding can be any one or more of resistance spot welding, laser spot welding, or arc spot welding; laser ring welding can be continuous ring welding or segmented ring welding.

[0045] In application, the support ring 7 and the pressure-sensing element 3 are fixed by three-point welding, which ensures structural strength while avoiding the formation of a large heat-affected zone, thereby reducing the impact of welding thermal stress on the performance of the pressure-sensing element 3. At the same time, the metal shell 2 and the pressure-sensing element 3 are encapsulated by laser ring welding, which makes the encapsulation weld continuous and uniform, effectively improving sealing consistency and pressure resistance. The combined application of three-point welding and laser ring welding at different structural levels enables the sensor to achieve high-reliability sealing and stable assembly while ensuring structural compactness, thereby solving the problems of single welding method and insufficient welding stability and consistency in the existing technology.

[0046] In other embodiments, the number of three-point welding points can be adjusted to more than three points according to the structural dimensions; laser ring welding adopts a continuous scanning method or a segmented skip welding method; and the welding parameters are adaptively adjusted according to the material thickness and pressure rating.

[0047] Regarding the specific structure of the second circuit board 42 mentioned above, this embodiment is as follows: Figures 2 to 4 As shown, the surface of the second circuit board 42 is printed with metal circuits and second surface pads 421, and resistors and / or capacitors are mounted on the metal circuits and pads.

[0048] The pressure-sensing element 3 is electrically connected to the second surface pad 421 via a binding wire.

[0049] In application, by printing metal circuits and second surface pads 421 on the surface of the second circuit board 42, and mounting resistors and / or capacitors on it, the second circuit board 42 can serve as a direct carrier for the signal of the pressure sensing element 3, and also undertake basic signal conditioning and parameter matching functions. The pressure sensing element 3 is electrically connected to the second surface pads 421 by a wire binding method, which shortens the signal transmission path and reduces parasitic parameters, thus improving signal stability and anti-interference ability. The wire binding structure of the pressure sensing element 3 is fixed to the second circuit board 42 by a support ring 7, which avoids the wire binding from bearing additional mechanical stress under vibration conditions, thereby improving the long-term reliability of the electrical connection.

[0050] In other embodiments, the second circuit board 42 is a ceramic circuit board or a high heat-resistant FR4 circuit board; the binding wire is made of gold wire, aluminum wire or alloy wire; and the second circuit board 42 integrates ESD protection or filtering circuits to enhance electrical safety.

[0051] Regarding the specific structure of the flexible connecting plate 43 connecting the first circuit board 41 and the second circuit board 42, this embodiment is as follows: Figure 3 and Figure 4 As shown, the two ends of the flexible connecting plate 43 are respectively fixedly connected to the first circuit board 41 and the second circuit board 42 by welding and / or connector insertion.

[0052] In application, the first circuit board 41 and the second circuit board 42 are electrically connected by the flexible connecting plate 43, so that the two circuit boards have a certain degree of spatial freedom while maintaining electrical connection, thus allowing them to be arranged in layers or staggered according to the internal structure of the sensor. The flexible connection, in conjunction with the structure of the support ring 7 and the spring seat 6, ensures that the connection between the circuit boards has reliable electrical performance and can absorb displacement changes caused by assembly tolerances and thermal expansion and contraction, thereby reducing stress concentration and improving the durability and reliability of the overall structure.

[0053] In other embodiments, the flexible connecting plate 43 is a single-layer or multi-layer FPC structure; its connection with the first and second circuit boards 42 is selected by direct welding or detachable connector connection according to assembly requirements.

[0054] A second implementation of a micro-fuse high-voltage sensor for automotive applications, for example Figure 2 and Figure 4 As shown, the difference between this embodiment and the first embodiment is that the pressure sensing element 3 includes a stainless steel housing 31, glass glue, and a strain gauge 32. The strain gauge 32 is fixed to the surface of the stainless steel housing 31 facing the second circuit board 42 by using glass glue as an adhesive carrier.

[0055] In application, the strain gauge 32 is fixed to the surface of the stainless steel housing 31 facing the second circuit board 42 by using glass glue as an adhesive carrier. This allows the strain gauge 32 to directly sense the minute deformation of the pressure sensing element 3 under pressure. Reliable insulation and long-term stable fixation are achieved through the glass glue. This fixing structure, combined with the close-range wire binding connection of the second circuit board 42, makes the signal transmission path short and stable, which is beneficial to improving measurement accuracy and long-term drift performance, thereby meeting the accuracy and stability requirements of automotive high-voltage applications.

[0056] In addition, the strain gauge 32 can be a metal strain gauge 32 or a thin film strain gauge 32; the formulation and curing method of the glass adhesive need to be adjusted according to the working temperature and pressure level.

[0057] A third implementation of a micro-fuse high-voltage sensor for automotive applications, for example Figure 2 and Figure 3 As shown, the difference between this embodiment and the first embodiment is that the first circuit board 41 is provided with a signal conditioning chip 412, which is used to amplify, filter and / or compensate for temperature drift of the output signal of the pressure sensing element 3; the signal conditioning chip 412 is arranged toward the cavity of the spring seat 6.

[0058] In application, a signal conditioning chip 412 is set on the first circuit board 41 to amplify, filter and / or compensate for temperature drift of the output signal of the pressure sensing element 3, making the sensor output signal more stable and accurate. The signal conditioning chip 412 is arranged toward the cavity of the spring seat 6, so that the chip can obtain reliable structural protection in a limited space and form a cooperative avoidance relationship with the spring seat 6. Thus, a highly integrated circuit layout can be achieved without increasing the size of the sensor, effectively solving the problems of low circuit integration and insufficient space utilization in the prior art.

[0059] In addition, the signal conditioning chip 412 integrates temperature sensing, calibration or diagnostic functions; the cavity is customized according to the size of the signal conditioning chip 412 to further optimize the internal layout.

[0060] Based on the above embodiments of the automotive micro-fuse high-voltage sensor, a method for manufacturing the automotive micro-fuse high-voltage sensor is provided, such as... Figure 5 As shown, the following steps are performed sequentially according to S1 to S6: S1, cavity formation: the metal shell and the plastic connector are fixedly connected to form a cavity; S2. Second circuit board connection: The pressure sensing element is inserted into the support ring, and the pressure sensing element is connected to the second surface pad of the second circuit board via a binding wire. The second circuit board is connected to the first circuit board via a flexible connecting plate. S3. Fixing the support ring to the second circuit board: Fix the support ring to the second circuit board by mounting and reflow soldering; S4. Fixing the support ring to the pressure sensing element: Fix the bottom outer ring of the support ring to the stepped surface of the pressure sensing element by welding at three points; S5. First circuit board connection: After fixing the first circuit board and the spring seat with hot riveting or glue, install them into the receiving cavity, and install the spring into the inner cavity of the plastic connector and pass it through to the first surface pad of the first circuit board. The first surface pad is electrically connected to the spring. S6. Packaging: After assembly, laser welding is performed on the bottom outer circle of the metal casing and the stepped surface of the pressure sensing element to achieve packaging.

[0061] In application, the automotive micro-fuse high-voltage sensor is manufactured by following steps S1 to S6 in sequence, so that the internal functional modules of the sensor gradually form a stable and controllable structural relationship during the assembly process: In S1, a receiving cavity consisting of a metal shell and a plastic connector is first formed to provide a unified assembly standard for subsequent circuit components and pressure sensing components; In S2, the pressure-sensing element is first fitted into the support ring and electrically connected to the second surface pad of the second circuit board by binding wire. At the same time, the second circuit board and the first circuit board are electrically interconnected through the flexible connecting plate, so that the pressure-sensing signal path is completely established in the early stage. In S3 and S4, the support ring is fixed to the second circuit board and the pressure sensing element respectively by reflow soldering and three-point soldering, so that the second circuit board can obtain reliable support in the radial and axial directions and form a stable structural integration with the pressure sensing element, thereby avoiding circuit board displacement or wire stress during subsequent assembly. In S5, the first circuit board is fixed to the spring seat and then installed into the receiving cavity as a whole, and the spring passes through the first surface pad of the first circuit board to complete the electrical connection. The electrical signal is brought out of the structure internalized, reducing the number of external electrical connection layers. Finally, in S6, laser ring welding is used to achieve the overall encapsulation of the metal shell and the pressure-sensing element, so that the sensor is sealed and fixed after all internal structures and electrical connections are completed, thereby ensuring that the welding heat effect will not damage the internal electrical connection structure.

[0062] Through the above manufacturing method, each step forms a synergistic relationship in terms of structural assembly sequence, electrical connection establishment timing, and welding process distribution. This allows the internal structure of the sensor to be gradually solidified from the inside out, and the electrical connections to be established step by step from the core to the ports. This not only helps to improve assembly consistency and production efficiency, but also significantly reduces the problems of electrical connection damage, structural stress concentration, or reliability decline caused by improper assembly sequence. Thus, it effectively solves the technical problems of complex assembly, limited efficiency, and insufficient long-term reliability in the manufacturing process of existing automotive micro-fused high-voltage sensors.

[0063] In other implementations, the execution order of S2 and S3 can be adjusted according to the specific production line configuration. For example, the support ring and the second circuit board can be fixed by reflow soldering first, and then the pressure sensing element can be assembled and wired. The fixing method of the first circuit board and the spring seat in S5 can be selected by hot riveting, adhesive bonding or a combination of both according to the material characteristics. The laser ring welding adopts continuous scanning or segmented scanning method, and the welding power and speed are adjusted according to the pressure resistance level.

[0064] Furthermore, each step in the above manufacturing method is connected and assembled using automated equipment to further improve production efficiency and product consistency.

[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A novel micro-fuse high-voltage sensor for automotive applications, characterized in that, It includes a plastic connector, a metal housing, a pressure-sensing element, a first circuit board, a second circuit board, a flexible connecting plate, a spring, a spring seat, and a support ring; The metal housing is connected to the plastic connector to form a receiving cavity, and the pressure-sensing element is located at the pressure-bearing end of the receiving cavity; The first circuit board and the second circuit board are electrically connected through the flexible connecting plate to form a rigid-flex circuit structure. The support ring is disposed between the second circuit board and the pressure sensing element, and the support ring and the second circuit board are fixed by mounting and reflow soldering. The bottom outer ring of the support ring is fixed to the stepped surface of the pressure sensing element by three-point welding. The spring seat is disposed between the first circuit board and the second circuit board, and the first circuit board and the spring seat are fixed by heat riveting or glue. One end of the spring is inserted into the inner cavity of the plastic connector and passes through the first circuit board, while the other end is electrically connected to an external port. The bottom outer circle of the metal casing and the stepped surface of the pressure-sensing element are encapsulated by laser ring bonding; Furthermore, the electrical signal output by the pressure-sensing element is transmitted to the second circuit board via a binding wire, and the second circuit board transmits the signal to the first circuit board via the flexible connecting plate. The first circuit board is electrically connected to the spring via a first surface pad, and the spring transmits the electrical signal to an external port.

2. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The pressure-sensing element includes a stainless steel housing, glass glue, and a strain gauge. The strain gauge is fixed to the surface of the stainless steel housing facing the second circuit board using the glass glue as an adhesive carrier.

3. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The metal casing is fixedly connected to the plastic connector by injection molding and / or riveting.

4. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The support ring is configured to provide radial positioning and / or axial limiting for the second circuit board to reduce relative displacement under vehicle vibration and thermal cycling conditions.

5. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The three-point welding is any one or more of resistance spot welding, laser spot welding, or arc spot welding; The laser ring welding is either continuous ring welding or segmented ring welding.

6. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The second circuit board has metal circuits and second surface pads printed on its surface, and resistors and / or capacitors are mounted on the metal circuits and pads.

7. The automotive micro-fuse high-voltage sensor according to claim 6, characterized in that, The pressure-sensing element is electrically connected to the second surface pad via the binding wire.

8. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The first circuit board is equipped with a signal conditioning chip for amplifying, filtering and / or compensating for temperature drift of the output signal of the pressure sensing element; The signal conditioning chip is arranged toward the cavity of the spring seat.

9. The automotive micro-fuse high-voltage sensor according to claim 1, characterized in that, The two ends of the flexible connecting plate are respectively fixedly connected to the first circuit board and the second circuit board by welding and / or connector insertion.

10. A method for manufacturing a micro-fuse high-voltage sensor for vehicles, comprising manufacturing the micro-fuse high-voltage sensor for vehicles according to any one of claims 1 to 9, characterized in that, The process includes the following steps: S1, cavity formation: the metal shell and the plastic connector are fixedly connected to form a cavity; S2. Second circuit board connection: The pressure sensing element is inserted into the support ring, and the pressure sensing element is connected to the second surface pad of the second circuit board via a binding wire. The second circuit board is connected to the first circuit board via a flexible connecting plate. S3. Fixing the support ring to the second circuit board: Fix the support ring to the second circuit board by mounting and reflow soldering; S4. Fixing the support ring to the pressure sensing element: Fix the bottom outer ring of the support ring to the stepped surface of the pressure sensing element by welding at three points; S5. First circuit board connection: After fixing the first circuit board and the spring seat with hot riveting or glue, install them into the receiving cavity, and install the spring into the inner cavity of the plastic connector and pass it through to the first surface pad of the first circuit board. The first surface pad is electrically connected to the spring. S6. Packaging: After assembly, laser welding is performed on the bottom outer circle of the metal casing and the stepped surface of the pressure sensing element to achieve packaging.

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