A sensor and assembly method for connecting a fisheye terminal to a ceramic core and a circuit board

Abstract

The application discloses a sensor for connecting a fish-eye terminal to a ceramic core and a circuit board and an assembling method, and relates to the technical field of sensors.The sensor comprises a first fish-eye PIN needle, a first fish-eye section of which is inserted into and clamped in a circuit through hole of a circuit hard board, and forms an electrical connection with a circuit contact ring; a first straight handle section is used for electrical connection with an external element; a second fish-eye PIN needle, a second fish-eye section of which is inserted into the circuit through hole of the circuit hard board and forms an electrical connection with the circuit contact ring; and a second connecting section is embedded in a circuit connecting hole of a ceramic core and forms an electrical connection with a line contact ring; through the plug-in connection structure, the circuit hard board and the external element and the ceramic core can be quickly assembled and an electrical connection of non-damaged components is established at normal temperature through the plug-in mode, without a brazing process, so that the problems of missing welding and false welding are avoided, the assembling efficiency and reliability are improved, and the labor and process costs are reduced; and the problems of easy damage of components and difficulty in automatic assembling of existing sensors are solved.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a sensor and assembly method for connecting a ceramic core and a circuit board using a fisheye terminal. Background Technology

[0002] With the increasing demand for sensors in applications such as automotive air conditioning, energy storage refrigeration, and automotive transmissions, the structural design and manufacturing process of sensors have gradually become important factors affecting product performance and cost.

[0003] Currently, common ceramic pressure or temperature sensors in the industry typically require a reliable electrical connection between the ceramic core and the circuit board. In existing technologies, brazing is commonly used to weld the ceramic core to the circuit board. Although brazing can ensure conductivity to a certain extent, the process has significant limitations.

[0004] First, brazing relies heavily on manual operation, making automated production difficult. In mass production, operators must complete the heating, solder filling, and joint forming steps one by one, resulting in low production efficiency and susceptibility to variations in operator skill and environmental factors, leading to inconsistent product quality. Second, brazing demands high labor intensity from workers, resulting in significantly higher labor costs, which hinders cost reduction in large-scale applications. Third, brazed connections are prone to quality issues such as incomplete soldering, weak soldering, or poor solder joints, causing unstable electrical performance and potentially leading to sensor failure in severe cases.

[0005] To accommodate the connection between the ceramic core and external connectors, most existing ceramic capacitive pressure sensors employ flexible printed circuit (FPCB) designs. While FPCBs offer some flexibility, they suffer from low positioning accuracy during automated assembly, are prone to bending and deformation, and can negatively impact the stability of subsequent welding or insertion processes. Furthermore, the FPCB material itself exhibits insufficient durability and resistance to mechanical shock under long-term operating conditions, hindering the improvement of the sensor's overall reliability.

[0006] On the other hand, the brazing process requires heating the solder, which may generate byproducts such as welding fumes and metal residues, adversely affecting the production environment and the health of operators, and is inconsistent with the current trend of green manufacturing and environmentally friendly production. Therefore, existing technologies have room for improvement in multiple dimensions, including reliability, automation, environmental friendliness, and cost control.

[0007] In summary, the existing technology has at least the following technical problems:

[0008] The existing brazing process used for sensor connection components with ceramic cores and flexible circuit boards is costly, prone to missing solder joints and poor solder joints, and has low assembly efficiency and reliability, making it difficult to achieve automated production. Summary of the Invention

[0009] The purpose of this invention is to provide a sensor and assembly method for connecting a ceramic core and a circuit board with a fisheye terminal, so as to solve the problem that the existing sensor connection elements with ceramic core and flexible circuit board rely on the brazing process, which has high cost, easy to produce missing solder and poor solder, low assembly efficiency and reliability, and is difficult to achieve automated production.

[0010] 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.

[0011] To address the aforementioned technical problems, the present invention provides the following technical solution:

[0012] This invention provides a sensor with a fisheye terminal connecting a ceramic core and a circuit board, comprising a first fisheye PIN pin electrically connected to internal and external components, a circuit rigid board, a second fisheye PIN pin electrically connected to internal components, and a ceramic core as a pressure-sensing element; the first fisheye PIN pin has a first fisheye segment and a first straight shank segment at its two ends; a circuit contact ring is provided in the circuit through-hole of the circuit rigid board; the first fisheye segment is inserted into and snapped into the circuit through-hole, and forms an electrical connection with the circuit contact ring; the first straight shank segment is used for electrical connection with external components; the second fisheye PIN pin has a second fisheye segment and a first straight shank segment at its two ends. The ceramic core has two connecting sections; a circuit contact ring is provided in the circuit connection hole; the second fisheye section is inserted into and snapped into the circuit through hole, and forms an electrical connection with the circuit contact ring; the second connecting section is embedded in the circuit connection hole, and forms an electrical connection with the circuit contact ring; the electrical connection between the circuit board and external components and the internal ceramic core is formed at room temperature by a quick plug-in connection through the first fisheye section and the second fisheye section, respectively, to reduce damage to the circuit board and the ceramic core during assembly, and to improve the reliability of the circuit board and the ceramic core after assembly.

[0013] In one embodiment, the width of the first fisheye segment gradually increases from its pointed end to the junction with the first straight shank segment and then decreases. The middle part of the first fisheye segment is the widest part, and the middle of the arc on both sides forms an outward protruding rib, giving it an overall fisheye shape. An elliptical hollow is provided between the arc on both sides of the first fisheye segment and at the center of the plane on both sides of the first fisheye segment to provide elastic contraction space for the protruding ribs on both sides when the first fisheye segment is inserted into the circuit through hole. The ends of the first straight shank segment have chamfers on both sides to guide insertion into the connecting hole, and a circumferentially arranged first positioning block is provided between the first straight shank segment and the first fisheye segment.

[0014] In one embodiment, the width of the second fisheye segment gradually increases from its pointed end to the junction with the second connecting segment and then decreases. The middle part of the second fisheye segment is the widest part, and the middle of the arcs on both sides forms outward protruding ribs, giving it an overall fisheye shape. An elliptical hollow is provided between the arcs on both sides of the second fisheye segment and at the center of the planes on both sides of the second fisheye segment to provide elastic contraction space for the protruding ribs on both sides when the second fisheye segment is inserted into the circuit through hole. The end of the second connecting segment is provided with a cross-shaped contact block that is electrically connected to the ceramic core. The cross-shaped contact block abuts against the circuit contact ring to form an electrical connection. A second positioning block is provided circumferentially arranged between the second connecting segment and the second fisheye segment.

[0015] In one embodiment, the plurality of circuit connection holes are arranged on the base of the ceramic core in a manner that is either all concentrated, all uniformly dispersed, or partially concentrated and partially dispersed.

[0016] In one embodiment, the circuit connection hole is a through hole penetrating the base of the ceramic core, and the junction of the circuit connection hole and the end face of the ceramic core facing the circuit rigid plate is a flat surface; or the end face of the ceramic core facing the circuit rigid plate is provided with a countersunk hole, and the circuit connection hole is located in the countersunk hole and penetrates the base of the ceramic core; or the end face of the ceramic core facing the circuit rigid plate is provided with a recessed seat, and the circuit connection hole is located on the recessed seat and penetrates the base of the ceramic core.

[0017] In one embodiment, elastic sheets are provided on both sides of the first fisheye segment and the second fisheye segment; one end of the elastic sheet is connected to the pointed end of the first fisheye segment and the second fisheye segment; the other end of the elastic sheet is suspended above the elliptical hollow.

[0018] In one embodiment, the linear length of the projection of the elastic sheet onto the plane with the elliptical cutout is equal to or shorter than the depth of the circuit through-hole of the circuit rigid board through which the first fisheye segment or the second fisheye segment passes, and the end of the elastic sheet is used to abut or snap against the end face plane of the circuit rigid board after the first fisheye segment or the second fisheye segment passes through the circuit through-hole, so that the first fisheye pin or the second fisheye pin is reliably inserted into the circuit rigid board.

[0019] In one embodiment, the end portion of the elastic sheet suspended above the elliptical cutout has a curled portion, which curls toward the elliptical cutout.

[0020] In one embodiment, the device further includes a detection housing and an inner sealing ring; one side of the detection housing has a pressure-sensing cavity for accommodating the ceramic core, and the opposite end has a detection head, the center of which has a fluid channel communicating with the pressure-sensing cavity; the strain gauge of the ceramic core faces the fluid channel, the inner sealing ring is disposed between the strain gauge of the ceramic core and the fluid channel, and the inner sealing ring surrounds the fluid channel, sealingly abutting the plane of the strain gauge of the ceramic core and the bottom surface of the pressure-sensing cavity; and a connector and RTV adhesive; the two sides of the connector are an external connection side and an internal connection side, respectively; between the external connection side and the internal connection side... A baffle wall is provided, with a through-hole for the first fisheye PIN pin to pass through. The first fisheye segment passes through the through-hole from the external side and is inserted into the circuit through-hole of the circuit board. The first positioning block is connected to the end face of the through-hole on the external side. The first straight shank segment is located in the space between the baffle wall and the external side, and is used for the connector of an external component to connect to the first fisheye PIN pin. The external side is electrically connected to the external component. The internal side accommodates the circuit board and is embedded in the pressure-sensing cavity of the detection housing. The junction between the detection housing and the internal side is sealed with RTV adhesive.

[0021] A sensor assembly method is also provided, based on a sensor that connects a ceramic core and a circuit board using fisheye terminals, including the following steps: S1, Sub-component positioning and assembly: The connector and ceramic core are distributed and temporarily fixed to their respective assembly fixtures by an automated feeding mechanism; The first fisheye PIN and the second fisheye PIN are respectively fed to the assembly fixtures above the connector and the ceramic core by an automated pin insertion mechanism, and the first fisheye segment of the first fisheye PIN is inserted into the through-hole facing the connector and engaged with the first positioning block; The second connecting segment of the second fisheye PIN is embedded into the circuit connection hole of the ceramic core.

[0022] S2. Sub-component assembly: The automated insertion mechanism picks up the circuit board delivered by the automated feeding mechanism, inserts the circuit through hole of the circuit board into the second fisheye segment of the second fisheye PIN, then picks up the assembled connector, faces the circuit board with the inner side, and inserts the first fisheye segment of the first fisheye PIN into the corresponding circuit through hole of the circuit board, so that the circuit board, ceramic core, and the first and second fisheye PINs can achieve mechanical locking and electrical connection without soldering at room temperature.

[0023] S3. Testing and Calibration: The electrical path between the first and second fisheye pins and the circuit board and ceramic core is tested by an automated testing device. If the connection resistance meets the preset standard, the sensor assembly is completed and the sensor enters the subsequent packaging or calibration process.

[0024] S4. Housing Encapsulation: The detection housing is temporarily fixed to the preset position of the assembly fixture by an automated feeding mechanism. The inner sealing ring is placed into the pressure sensing chamber by an automated assembly mechanism, and the axis of the inner sealing ring is aligned with the center of the fluid channel. The automated plugging mechanism picks up the connector containing the circuit board and ceramic core, and embeds the inner side of the connector into the pressure sensing chamber of the detection housing. The RTV adhesive is applied and cured at the joint between the detection housing and the connector by an automated dispensing process to complete the sealing of the internal electrical unit.

[0025] The sensor technology proposed in this invention, which uses fisheye terminals to connect the ceramic core and the circuit board, overcomes the problems of high cost, high risk of missing or faulty solder joints, low assembly efficiency and reliability, and difficulty in achieving automated production caused by the reliance on brazing processes between the ceramic core and the flexible circuit board in existing technologies. It has the following beneficial effects:

[0026] (1) Achieving solderless and rapid connection: By setting a circuit contact ring in the circuit through hole of the circuit board and a line contact ring in the circuit connection hole of the ceramic core, and utilizing the plug-in locking structure of the fisheye section of the first fisheye PIN and the second fisheye PIN, the electrical connection with the circuit board and the ceramic core can be completed at room temperature; and no high-temperature brazing and solder are required. Through plug-in assembly, welding defects are avoided and the processing complexity is reduced.

[0027] (2) Improve assembly efficiency and automation level. The fisheye segment structure of the first fisheye PIN and the second fisheye PIN is matched with each contact ring. The fisheye segment expands and abuts in the contact ring to form electrical contact, which can achieve rapid insertion and reliable locking. It is suitable for mechanized and automated assembly line operations, greatly reducing manual operation steps and reducing production cycle and labor costs.

[0028] (3) Enhanced connection reliability and service life: The fisheye segment forms an interference fit and a multi-point contact in the extrusion manner with the circuit contact ring and the line contact ring, which improves the stability of the electrical connection and reduces the risk of loose connection or loosening. At the same time, the straight shank segments of the first fisheye PIN pin and the second fisheye PIN pin are mechanically locked with the connector and the ceramic core, respectively, ensuring that the sensor can still maintain a reliable connection with the internal circuit structure and external connected components under complex environments such as vibration and thermal shock.

[0029] (4) Reduce overall cost and improve environmental adaptability. Using rigid boards instead of flexible boards not only improves the rigidity and durability of the circuit board, but also makes it easier to match with external connectors. Solder-free design reduces the consumption of solder, welding machine and labor, reduces overall cost, and avoids welding fumes and residues, achieving green and environmentally friendly manufacturing.

[0030] In summary, this invention achieves rapid, reliable, weld-damage-free, and environmentally friendly assembly and connection of the ceramic core, circuit board, and external components through the insertion method of fisheye terminals and contact rings, thereby significantly improving the assembly efficiency, yield, reliability, and industrial application value of the sensor. Attached Figure Description

[0031] 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.

[0032] Figure 1 This is a front view structural diagram of the sensor of the present invention;

[0033] Figure 2 This is a cross-sectional structural schematic diagram of the sensor of the present invention;

[0034] Figure 3 This is a front view structural schematic diagram of the second fisheye PIN pin of the present invention;

[0035] Figure 4 This is a bottom view of the structure of the second fisheye PIN needle of the present invention;

[0036] Figure 5 This is a front view schematic diagram of the second fisheye PIN needle of the present invention having an elastic sheet;

[0037] Figure 6 This is a top view schematic diagram of the circuit connection holes of the present invention arranged on the ceramic core in a flat surface and in a concentrated manner.

[0038] Figure 7 This is a top view of the circuit connection hole of the present invention in the form of a countersunk hole on the ceramic core;

[0039] Figure 8 This is a top view of the circuit connection hole of the present invention in the form of a recessed seat on the ceramic core;

[0040] Figure 9 This is a top view schematic diagram of the circuit connection holes of the present invention arranged in a uniformly dispersed manner on the ceramic core.

[0041] Figure 10 This is a top view schematic diagram of the circuit connection holes of the present invention arranged on the ceramic core in a partially clustered and partially dispersed manner.

[0042] The reference numerals in the attached figures are as follows:

[0043] 1. First fisheye pin; 11. First fisheye segment; 12. First straight shank segment; 121. First positioning block;

[0044] 2. Circuit board; 21. Circuit through-hole; 22. Circuit contact ring;

[0045] 3. Second fisheye PIN pin; 31. Second fisheye segment; 32. Second connecting segment; 321. Cross contact block; 322. Second positioning block;

[0046] 41. Oval-shaped cutout; 42. Raised ribs; 43. Elastic sheet; 431. Curved section;

[0047] 5. Ceramic core; 51. Base; 52. Strain gauge; 53. Circuit connection hole; 54. Circuit contact ring; 55. Countersunk hole; 56. Recessed seat;

[0048] 6. Detector housing; 61. Pressure sensing chamber; 62. Detector head; 621. Fluid channel;

[0049] 71. Inner sealing ring; 72. Outer sealing ring;

[0050] 8. Connector; 81. External side; 82. Internal side; 83. Barrier; 831. Through-hole;

[0051] 9. RTV adhesive. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0053] A specific embodiment provides a sensor and assembly method for connecting a ceramic core and a circuit board using fisheye terminals. The sensor includes a first fisheye PIN pin, with its first fisheye segment inserted into and snapped into a circuit through-hole on a rigid circuit board, forming an electrical connection with a circuit contact ring; a first straight shank segment is used for electrical connection with external components; a second fisheye PIN pin, with its second fisheye segment inserted into a circuit through-hole on the rigid circuit board, forming an electrical connection with the circuit contact ring; and a second connecting segment embedded in a circuit connection hole of the ceramic core, forming an electrical connection with a circuit contact ring. Through the plug-in connection structure, the rigid circuit board, external components, and ceramic core can be quickly assembled and a non-damaging electrical connection can be established between them at room temperature via plug-in connection, eliminating the need for brazing and avoiding issues such as missing solder joints and cold solder joints. This also improves assembly efficiency and reliability, and reduces labor and process costs. It effectively solves the problem of existing sensor connection elements with ceramic cores and flexible circuit boards relying on brazing processes, which are costly, prone to missing solder joints and cold solder joints, and have low assembly efficiency and reliability, making automated production difficult.

[0054] The first implementation of a sensor that connects the ceramic core 5 and the circuit board via a fisheye terminal is, for example... Figure 1 and Figure 2 As shown, the circuit includes a first fisheye PIN 1 (conductive pin, pin header) electrically connected to internal and external components, a circuit board 2, a second fisheye PIN 3 electrically connected to internal components, and a ceramic core 5 serving as a pressure-sensing element. The first fisheye PIN 1 has a first fisheye segment 11 and a first straight shank segment 12 at its two ends. A circuit contact ring 22 is provided within the circuit through-hole 21 of the circuit board 2, and the circuit contact ring 22 is electrically connected to the internal circuitry of the circuit board 2. The first fisheye segment 11 is inserted into and engaged within the circuit through-hole 21, forming an electrical connection with the circuit contact ring 22. The first straight shank segment 12 is used for electrical connection to external components. The second fisheye PIN 3 has a second fisheye segment 31 and a second connecting segment 32 at its two ends. The ceramic core 5 has a circuit... A circuit contact ring 54 is provided inside the connection hole 53, and the circuit contact ring 54 is electrically connected to the internal circuit of the ceramic core 5; the second fisheye segment 31 is inserted into and snapped into the circuit through hole 21, and forms an electrical connection with the circuit contact ring 22; the second connecting segment 32 is embedded in the circuit connection hole 53, and forms an electrical connection with the circuit contact ring 54; the electrical connection between the circuit rigid board 2 and the external components and the internal ceramic core 5 is formed by the first fisheye segment 11 and the second fisheye segment 31 respectively, and is formed by a quick plug-in connection at room temperature, which is used to reduce the damage of the circuit rigid board 2 and the ceramic core 5 during assembly, and improve the reliability of the circuit rigid board 2 and the ceramic core 5 after assembly.

[0055] The technical solution of connecting the ceramic core 5 and the circuit board through fisheye terminals overcomes the problems of high cost, high risk of missing solder joints and poor solder joints, low assembly efficiency and reliability, and difficulty in achieving automated production caused by the reliance on brazing process between the ceramic core 5 and the flexible circuit board in the existing technology. It has several technical advantages: it achieves rapid connection without soldering. By setting a circuit contact ring 22 in the circuit through hole 21 of the circuit rigid board 2 and a line contact ring 54 in the circuit connection hole 53 of the ceramic core 5, and utilizing the plug-in locking structure of the fisheye segments of the first fisheye PIN pin 1 and the second fisheye PIN pin 3, the electrical connection with the circuit rigid board 2 and the ceramic core 5 can be completed at room temperature; and no high-temperature brazing and solder are required. Through plug-in assembly, welding defects are avoided and the processing complexity is reduced.

[0056] To improve assembly efficiency and automation, the fisheye segment structure of the first fisheye PIN 1 and the second fisheye PIN 3 is matched with each contact ring. The fisheye segment expands and abuts within the contact ring to form electrical contact, which can achieve quick insertion and reliable locking. It is suitable for mechanized and automated assembly line operations, greatly reducing manual operation steps and lowering production cycle and labor costs.

[0057] To enhance connection reliability and service life, the fisheye segment forms an interference fit and compression-type multi-point contact with the circuit contact ring 22 and the line contact ring 54, which improves the stability of the electrical connection and reduces the risk of loose connections or loosening. At the same time, the straight shank segments of the first fisheye PIN pin 1 and the second fisheye PIN pin 3 are mechanically locked to the connector 8 and the ceramic core 5, respectively, ensuring that the sensor can maintain a reliable connection with the internal circuit structure and external connected components even under complex environments such as vibration and thermal shock.

[0058] Reducing overall costs and improving environmental adaptability, the use of rigid boards instead of flexible boards not only improves the rigidity and durability of the circuit board, but also makes it easier to match with external connectors 8; the solderless design reduces the consumption of solder, welding machines and labor, lowers overall costs, and avoids welding fumes and residues, achieving green and environmentally friendly manufacturing.

[0059] In summary, this invention achieves a fast, reliable, weld-damage-free, and environmentally friendly assembly connection between the ceramic core 5, the circuit board 2, and external components through the insertion method of the fisheye terminal and the contact ring, thereby significantly improving the assembly efficiency, yield, reliability, and industrial application value of the sensor.

[0060] As one alternative implementation method:

[0061] Regarding the specific shape and structure of the first fisheye PIN 1 and its role in component assembly, this embodiment is, for example... Figure 2 and Figure 3 As shown, the width of the first fisheye segment 11 gradually increases from the tip to the junction with the first straight stem segment 12, and then decreases, with the width being the largest in the middle. The middle of the arc on both sides forms an outward protruding rib 42, giving the whole a fisheye shape. The center of the plane on both sides of the arc of the first fisheye segment 11 is provided with an elliptical hollow 41, which provides elastic contraction space for the protruding rib 42 on both sides when the first fisheye segment 11 is inserted into the circuit through hole 21. The ends of the first straight stem segment 12 are provided with chamfers on both sides to guide the insertion into the connecting hole. A first positioning block 121 is arranged circumferentially between the first straight stem segment 12 and the first fisheye segment 11.

[0062] When applied, the first positioning block 121 at the first straight end of the first fisheye PIN pin 1 is inserted into the through hole 831 of the connector 8 and then positioned to limit the end face of the retaining wall 83. The first fisheye segment 11 of the first fisheye PIN pin 1 is then inserted into the circuit through hole 21 of the circuit board 2 by the insertion force and the guidance of the tip. The protruding rib 42 is compressed and reset under the elastic release of the elliptical hollow 41, so that the protruding rib 42 of the first fisheye segment 11 and the circuit contact ring 22 can be reliably locked together to form multi-point electrical contact, thereby ensuring the stability of the electrical connection between the first fisheye PIN pin 1 and the internal (circuit board 2) and external electronic components.

[0063] This structure not only avoids the problems of incomplete welding and missing welding caused by traditional welding, but also makes the insertion action smooth and the positioning accurate due to the gradually changing width of the fisheye section. It is suitable for automated equipment to complete the assembly, thus improving production efficiency and consistency.

[0064] In addition, the first fisheye PIN pin 1 can be designed in different sizes according to the diameter of the circuit board through hole and the specifications of different external connectors 8. A plating layer can also be added to the outer surface of the first straight shank section 12 to enhance conductivity and corrosion resistance, thereby further improving long-term reliability.

[0065] Regarding the specific shape and structure of the second fisheye PIN 3 and its role in component assembly, this embodiment is, for example... Figures 2 to 4 As shown, the width of the second fisheye segment 31 gradually increases from the tip to the junction with the second connecting segment 32, and then decreases, with the width being the largest in the middle. The middle of the arc on both sides forms an outward protruding rib 42, giving the whole a fisheye shape. The center of the plane on both sides of the arc of the second fisheye segment 31 is provided with an elliptical hollow 41, which provides elastic contraction space for the protruding rib 42 on both sides when the second fisheye segment 31 is inserted into the circuit through hole 21. The end of the second connecting segment 32 is provided with a cross contact block 321 that is electrically connected to the ceramic core 5. The cross contact block 321 abuts against the circuit contact ring 54 to form an electrical connection. A second positioning block 322 is arranged circumferentially between the second connecting segment 32 and the second fisheye segment 31.

[0066] In application, the fisheye segment of the second fisheye PIN 3 is inserted into the circuit through hole 21 of the circuit rigid board 2 and engages with the circuit contact ring 22 to conduct electricity. The cross contact block 321 at the end of the second connecting segment 32 is embedded in the circuit connection hole 53 of the ceramic core 5 and presses against the line contact ring 54 to form a reliable electrical connection between the ceramic core 5 and the circuit rigid board 2. Due to the limiting effect of the second positioning block 322 of the second fisheye PIN 3, the second fisheye PIN 3 can be prevented from becoming loose from the ceramic core 5 under vibration or external impact. This structure effectively avoids the problem of unstable resistance that is easy to cause by brazing connection and ensures the reliability of signal transmission of the sensor in long-term working environment.

[0067] In addition, the cross contact block 321 is shaped like a cross column, and a hemispherical structure is provided between the second positioning block 322 and the end of the cross contact block 321 to increase the connection strength between the cross contact block 321 and the circuit connection hole 53; at the same time, gold or silver can be plated on the surface of the cross contact block 321 to improve the contact conductivity with the ceramic core 5.

[0068] The arrangement of the circuit connection holes 53 on the ceramic core 5 is based on the position of the circuit through holes 21 on the circuit rigid board 2. When the sensor is designed with different circuit structures for different application scenarios, the position of the circuit through holes 21 on the circuit rigid board 2 will be redesigned. Therefore, the positions of the circuit connection holes 53 corresponding to the circuit through holes 21 also need to be rematched. For example, Figure 6 , Figure 9 and Figure 10 As shown, multiple circuit connection holes 53 are arranged on the base 51 of the ceramic core 5 in a manner that is all concentrated, all uniformly dispersed, or partially concentrated and partially dispersed.

[0069] In application, the circuit connection hole 53 of the ceramic core 5, which is connected to the second fisheye PIN 3, corresponds one-to-one with the circuit through hole 21 of the circuit rigid board 2. This allows the second fisheye PIN 3 on the ceramic core 5 to automatically align with the circuit rigid board 2 during assembly without additional adjustment or positioning. By designing the circuit connection hole 53 to be concentrated, evenly dispersed, or partially concentrated and partially dispersed, it can be flexibly adjusted according to different circuit board wiring schemes, improving the compatibility and modularity of the sensor design. This design solves the problem of low assembly efficiency and the need for manual alignment between the existing ceramic core 5 and the circuit board.

[0070] In addition, in high-density packaging applications, localized converged vias can be used to shorten the length of built-in wires in the circuit and reduce signal delay; while in applications with high voltage withstand requirements, uniformly distributed vias can be used to enhance electrical isolation capabilities.

[0071] Regarding the specific structure of the circuit connection hole 53 on the base 51 of the ceramic core 5, this embodiment is, for example... Figures 6 to 8 As shown, the circuit connection hole 53 is a through hole that penetrates the base 51 of the ceramic core 5, and the junction of the circuit connection hole 53 and the end face of the base 51 of the ceramic core 5 facing the circuit rigid plate 2 is a flat surface; or the end face of the base 51 of the ceramic core 5 facing the circuit rigid plate 2 is provided with a countersunk hole 55, and the circuit connection hole 53 is located in the countersunk hole 55 and penetrates the base 51 of the ceramic core 5; or the end face of the base 51 of the ceramic core 5 facing the circuit rigid plate 2 is provided with a recessed seat 56, and the circuit connection hole 53 is located on the recessed seat 56 and penetrates the base 51 of the ceramic core 5.

[0072] When applied, the circuit connection hole 53, whether configured as a simple through hole, countersunk hole 55, or recessed seat 56, can ensure reliable engagement between the cross contact block 321 of the second connection section 32 and the circuit contact ring 54. The flat surface of the circuit connection hole 53 is suitable for standard through-hole mating; the countersunk hole 55 enhances the contact area and pull-out resistance; and the recessed seat 56 increases the PIN insertion force and shock resistance. Thus, by selecting a specific circuit connection hole 53 structure, this design improves assembly reliability and adapts to different process scenarios.

[0073] In addition, the circuit connection hole 53 can be coated according to the different electrical performance requirements of the sensor, such as nickel plating or gold plating, to improve corrosion resistance and conductivity; insulating washers can also be added in the countersunk hole 55 or the recessed seat 56 to further improve the pressure resistance level.

[0074] Regarding the mating structure required when the sensor is used as a pressure sensor, this implementation is as follows: Figure 1 and Figure 2 As shown, it also includes a detection housing 6 and an inner sealing ring 71; a pressure-sensing cavity 61 is provided on one side of the detection housing 6 for accommodating the ceramic core 5, and a detection head 62 is provided on the opposite end. A fluid channel 621 is provided in the center of the detection head 62 and communicates with the pressure-sensing cavity 61; the strain gauge 52 of the ceramic core 5 faces the fluid channel 621, and the inner sealing ring 71 is provided between the strain gauge 52 of the ceramic core 5 and the fluid channel 621, and the inner sealing ring 71 surrounds the fluid channel 621 and seals against the plane of the strain gauge 52 of the ceramic core 5 and the bottom surface of the pressure-sensing cavity 61.

[0075] The connector 8 and RTV adhesive 9 (room temperature vulcanizing silicone rubber) are also present. The two sides of the connector 8 are an external side 81 and an internal side 82, respectively. A baffle 83 is provided between the external side 81 and the internal side 82. A through hole 831 is provided on the baffle 83 for the first fisheye PIN 1 to pass through. The first fisheye segment 11 passes through the through hole 831 from the external side 81 and is inserted into the circuit through hole 21 of the circuit board 2. The first positioning block 121 is connected to the end face of the external side 81 with the through hole 831. The first straight shank segment 12 is located in the space between the baffle 83 and the external side 81 and is used for the connector of the external component to connect to the first fisheye PIN 1. The external side 81 is electrically connected to the external component. The internal side 82 accommodates the circuit board 2 and is embedded in the pressure-sensing cavity 61 of the probe housing 6. The junction between the probe housing 6 and the internal side 82 is sealed by RTV adhesive 9.

[0076] Among them, an external sealing ring 72 is provided on the outer periphery of the probe head 62 for sealing with the target installation position.

[0077] In application, the ceramic core 5 is placed in the pressure-sensing cavity 61 of the probe housing 6, with its strain gauge 52 facing the fluid channel 621 of the probe head 62. External fluid acts on the strain gauge 52 through the fluid channel 621, causing the strain gauge 52 to deform and thus achieving pressure measurement. The inner sealing ring 71 forms an annular seal between the strain gauge 52 and the fluid channel 621, effectively preventing fluid leakage or impurities from entering, ensuring measurement accuracy and long-term stability.

[0078] Meanwhile, the connector 8 and the detection housing 6 are sealed with RTV glue 9 to prevent moisture and dust from entering and ensure the safety and reliability of the electrical unit; the first fisheye PIN pin 1 is positioned by the through hole 831 of the baffle 83 and its own first positioning block 121, which not only realizes the conduction with external components, but also enhances the mechanical limiting effect, thereby improving the overall vibration resistance and protection performance of the sensor.

[0079] In addition, the probe housing 6 can be designed as a metal or engineering plastic material according to different applications, and the inner sealing ring 71 can be made of corrosion-resistant materials such as fluororubber and silicone rubber to meet the different media environment requirements of automotive air conditioning, energy storage refrigeration or transmission oil pressure measurement.

[0080] A second embodiment of the sensor, for example, connects the ceramic core 5 and the circuit board via a fisheye terminal. Figure 5 As shown, the difference between this embodiment and the first embodiment is that elastic sheets 43 are provided on both sides of the first fisheye segment 11 and the second fisheye segment 31; one end of the elastic sheet 43 is connected to the pointed ends of the first fisheye segment 11 and the second fisheye segment 31; the other end of the elastic sheet 43 is suspended above the elliptical hollow 41.

[0081] Wherein, the projected straight line length of the elastic sheet 43 on the plane with the elliptical cutout 41 is equal to or shorter than the depth of the circuit through hole 21 of the circuit rigid board 2 through which the first fisheye segment 11 or the second fisheye segment 31 passes, and the end of the elastic sheet 43 is used to abut or snap against the end face plane of the circuit rigid board 2 after the first fisheye segment 11 or the second fisheye segment 31 passes through the circuit through hole 21, so that the first fisheye PIN pin 1 or the second fisheye PIN pin 3 can be reliably inserted into the circuit rigid board 2.

[0082] The circuit contact ring 22 has electrical contact bosses or planes on both sides or one side of the circuit rigid plate 2, which are used to form an additional electrical connection when it abuts or snaps against the end of the elastic sheet 43.

[0083] During application, the elastic plates 43 on both sides of the first fisheye segment 11 and the second fisheye segment 31 are compressed and undergo elastic deformation during insertion into the circuit through-hole 21 of the circuit rigid board 2. After the fisheye segment of the PIN pin has completely passed through the circuit through-hole 21, the end of the elastic plate 43 naturally resets at the exit of the circuit through-hole 21 and abuts or snaps against the end face of the circuit rigid board 2. This provides additional mechanical limiting and electrical redundancy conduction path on the basis of the electrical connection formed between the protruding rib 42 of the fisheye segment and the circuit contact ring 22. In practical applications, this technology can effectively improve the shock resistance and long-term stability of the circuit and PIN pin connection, avoid loosening or poor contact caused by vibration, thermal expansion and contraction, and solve the reliability deficiencies of traditional rigid connections.

[0084] In addition, the length and thickness parameters of the elastic sheet 43 can be optimized according to the depth of the through hole and the thickness of the circuit board 2, and it can be designed as a straight line, an arc or an interdigitated type to meet the assembly force and contact pressure requirements of different process scenarios. The material of the elastic sheet 43 can be selected as copper alloy, nickel-plated spring steel or gold-plated elastic material to further improve fatigue resistance and corrosion resistance.

[0085] A third embodiment of the sensor, for example, connects the ceramic core 5 and the circuit board via a fisheye terminal. Figure 5 As shown, the difference between this embodiment and the second embodiment is that the end portion of the elastic sheet 43 suspended above the elliptical hollow 41 is provided with a curled portion 431, and the curled portion 431 curls toward the elliptical hollow 41.

[0086] When applied, the curled portion 431 at the end of the elastic sheet 43 will produce a local snapping or clamping effect along the electrical contact plane or boss at the edge of the through hole 21 of the circuit rigid board 2 after the fisheye end of the PIN needle passes through the circuit through hole 21. This makes the elastic sheet 43 and the circuit rigid board 2 form a stronger mechanical engagement. In addition, the curled portion 431 increases the contact area of ​​the electrical connection while providing a limit, forming multi-point contact conduction. This not only enhances the locking strength of the PIN needle in the through hole, but also disperses the insertion force and external impact force, improving shock resistance and durability.

[0087] By designing the curled section 431 structure, the problem of loosening or contact attenuation that may occur in the flat elastic sheet 43 under extreme vibration environment in the second embodiment is solved, thereby ensuring the long-term reliability of the sensor under complex working conditions such as automobiles and energy storage.

[0088] Based on the above embodiment of the sensor connecting the ceramic core and the circuit board with fisheye terminals, a sensor assembly method is provided, including the following steps implemented in sequence S1 to S4: S1, Sub-component positioning and assembly: The connector and the ceramic core are distributed and temporarily fixed to the preset positions of their respective assembly fixtures by an automated feeding mechanism; The first fisheye PIN and the second fisheye PIN are respectively fed to the assembly fixtures of the connector and the ceramic core by an automated pin insertion mechanism, and the first fisheye segment of the first fisheye PIN is inserted into the through-hole facing the connector and engaged with the first positioning block; The second connecting segment of the second fisheye PIN is embedded into the circuit connection hole of the ceramic core;

[0089] S2. Sub-component assembly: The automated insertion mechanism picks up the circuit board delivered by the automated feeding mechanism, inserts the circuit through hole of the circuit board into the second fisheye segment of the second fisheye PIN, then picks up the assembled connector, faces the circuit board with the inner side, and inserts the first fisheye segment of the first fisheye PIN into the corresponding circuit through hole of the circuit board, so that the circuit board, ceramic core, and the first and second fisheye PINs can achieve mechanical locking and electrical connection without soldering at room temperature.

[0090] S3. Testing and Calibration: The electrical path between the first and second fisheye pins and the circuit board and ceramic core is tested by an automated testing device. If the connection resistance meets the preset standard, the sensor assembly is completed and the sensor enters the subsequent packaging or calibration process.

[0091] S4. Housing Encapsulation: The detection housing is temporarily fixed to the preset position of the assembly fixture by an automated feeding mechanism. The inner sealing ring is placed into the pressure sensing chamber by an automated assembly mechanism, and the axis of the inner sealing ring is aligned with the center of the fluid channel. The automated plugging mechanism picks up the connector containing the circuit board and ceramic core, and embeds the inner side of the connector into the pressure sensing chamber of the detection housing. The RTV adhesive is applied and cured at the joint between the detection housing and the connector by an automated dispensing process to complete the sealing of the internal electrical unit.

[0092] In application, the sensor assembly method uses an automated feeding and insertion mechanism to sequentially position, insert, and assemble the connector, ceramic core, circuit board, and fisheye pins, achieving mechanical locking and electrical conduction without the need for soldering at room temperature.

[0093] Specifically, the sub-component positioning and assembly process utilizes automated tooling to ensure that each component is in a precise position, avoiding errors caused by manual positioning. In the sub-component assembly process, an automated insertion mechanism enables the fisheye pin to quickly connect to the circuit board and ceramic core, allowing the fisheye section to achieve electrical connection with the contact ring of the circuit through hole and the straight shank section to achieve electrical connection with the circuit contact ring of the ceramic core simultaneously, thereby significantly improving assembly efficiency and consistency.

[0094] The testing and calibration process utilizes automated testing equipment to detect the circuit resistance in real time, enabling rapid screening of defective parts on the production line and ensuring product reliability.

[0095] The final housing encapsulation process uses dispensing and curing to achieve a sealed connection between the probe housing and the connector, effectively preventing the ingress of external dust, moisture, or working media, and ensuring long-term stable operation of the sensor.

[0096] This method solves the problems of high cost, high risk of missing or false soldering, low assembly efficiency and high dependence on manual labor in traditional brazing processes, enabling sensors to achieve high reliability in complex environments such as automotive air conditioning, energy storage refrigeration and automotive transmissions.

[0097] 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 sensor with a fisheye terminal connecting a ceramic core and a circuit board, characterized in that, It includes a first fisheye PIN pin electrically connected to internal and external components, a circuit board, a second fisheye PIN pin electrically connected to internal components, and a ceramic core as a pressure-sensing element; The first fisheye PIN needle has a first fisheye segment and a first straight shank segment at its two ends; The circuit board has a circuit contact ring inside the circuit through hole. The first fisheye segment is inserted into and snapped into the circuit through hole, and forms an electrical connection with the circuit contact ring; the first straight shank segment is used for electrical connection with external components. The second fisheye PIN pin has a second fisheye segment and a second connecting segment at both ends; The ceramic core is provided with a circuit contact ring in the circuit connection hole. The second fisheye segment is inserted into and snapped into the circuit through hole, and forms an electrical connection with the circuit contact ring; the second connecting segment is embedded in the circuit connecting hole, and forms an electrical connection with the circuit contact ring. The electrical connections between the circuit board and external components and the internal ceramic core are formed at room temperature through the first fisheye segment and the second fisheye segment, respectively, in a quick plug-in connection manner. This is used to reduce damage to the circuit board and the ceramic core during assembly and to improve the reliability of the circuit board and the ceramic core after assembly. The width of the first fisheye segment gradually increases from the tip to the junction with the first straight shank segment and then decreases. The middle part of the first fisheye segment is the widest part, and the middle part of the arc on both sides forms an outward protruding rib, and the whole is fisheye-shaped. An elliptical hollow is provided between the arcs on both sides of the first fisheye segment and at the center of the planes on both sides of the first fisheye segment, so as to provide elastic contraction space for the protruding ribs on both sides when the first fisheye segment is inserted into the circuit through hole. The ends of the first straight handle section are provided with chamfers on both sides to guide the insertion of the connecting hole, and a first positioning block arranged circumferentially is provided between the first straight handle section and the first fisheye section. The width of the second fisheye segment gradually increases from the tip to the junction with the second connecting segment and then decreases. The middle part of the second fisheye segment is the widest part, and the middle part of the arc on both sides forms an outward protruding rib, which is fisheye shaped as a whole. An elliptical hollow is provided between the two opposite arcs of the second fisheye segment and at the center of the two opposite planes of the second fisheye segment, so as to provide elastic contraction space for the protruding ribs on the opposite sides when the second fisheye segment is inserted into the circuit through hole; The end of the second connecting section is provided with a cross-shaped contact block that is electrically connected to the ceramic core. The cross-shaped contact block abuts against the circuit contact ring to form an electrical connection. A second positioning block arranged circumferentially is provided between the second connecting section and the second fisheye section; It also includes a detection housing and an inner sealing ring; one side of the detection housing is provided with a pressure-sensing cavity to accommodate the ceramic core, and the opposite end is provided with a detection head, the center of which is provided with a fluid channel communicating with the pressure-sensing cavity; The strain gauge of the ceramic core faces the fluid channel, and the inner sealing ring is disposed between the strain gauge of the ceramic core and the fluid channel, and the inner sealing ring surrounds the fluid channel, the plane of the strain gauge of the ceramic core, and the bottom surface of the pressure sensing cavity for sealing contact. And connectors and RTV adhesive; the two sides of the connector are the outer side and the inner side, respectively; A baffle is provided between the outer side and the inner side, and a through hole is provided on the baffle for the first fisheye PIN pin to pass through. The first fisheye segment passes through the through hole from the outer side and is inserted into the circuit through hole of the circuit board. The first positioning block is connected to the end face of the through hole on the external side, and the first straight shank is located in the space between the retaining wall and the external side, for connecting the connector of the external component to the first fisheye PIN pin. The external side is electrically connected to external components, and the internal side accommodates the circuit board and is embedded in the pressure-sensing cavity of the detection housing; The junction between the probe housing and the inner side is sealed with the RTV adhesive.

2. The sensor with a fisheye terminal connecting the ceramic core and the circuit board according to claim 1, characterized in that, The multiple circuit connection holes are arranged on the base of the ceramic core in a manner that is either all concentrated, all uniformly dispersed, or partially concentrated and partially dispersed.

3. The sensor with a fisheye terminal connecting the ceramic core and the circuit board according to claim 1, characterized in that, The circuit connection hole is a through hole that penetrates the base of the ceramic core, and the junction of the circuit connection hole and the end face of the ceramic core facing the circuit rigid plate is a flat surface. Alternatively, the base of the ceramic core may have a countersunk hole on the end face of the circuit board facing the base of the ceramic core, and the circuit connection hole may be located in the countersunk hole and pass through the base of the ceramic core. Alternatively, a recessed seat may be provided on the end face of the ceramic core base facing the circuit rigid plate, and the circuit connection hole may be provided on the recessed seat and penetrate the base of the ceramic core.

4. The sensor with a fisheye terminal connecting the ceramic core and the circuit board according to claim 1, characterized in that, Both the first and second fisheye segments have elastic tabs on their two side planes; One end of the elastic sheet is connected to the pointed ends of the first fisheye segment and the second fisheye segment; The other end of the elastic sheet is suspended above the elliptical cutout.

5. The sensor with a fisheye terminal connecting the ceramic core and the circuit board according to claim 4, characterized in that, The linear length of the projection of the elastic sheet on the plane with the elliptical cutout is equal to or shorter than the depth of the circuit through hole of the circuit rigid board through which the first fisheye segment or the second fisheye segment passes. The end of the elastic sheet is used to abut or snap against the end face plane of the circuit rigid board after the first fisheye segment or the second fisheye segment passes through the circuit through hole, so that the first fisheye pin or the second fisheye pin is reliably inserted into the circuit rigid board.

6. The sensor with a fisheye terminal connecting the ceramic core and the circuit board according to claim 5, characterized in that, The end portion of the elastic sheet suspended above the elliptical cutout has a curled portion, which curls toward the elliptical cutout.

7. A method for assembling a sensor, used to assemble a sensor with a fisheye terminal connecting a ceramic core and a circuit board according to claim 1, characterized in that, Includes the following steps: S1. Sub-component positioning and assembly: The connector and ceramic core are temporarily fixed to their respective preset positions in the assembly fixture by an automated feeding mechanism. An automated pin insertion mechanism delivers the first fisheye pin and the second fisheye pin to the assembly fixtures of the connector and the ceramic core, respectively. The first fisheye segment of the first fisheye pin is inserted into the through-hole of the connector and engaged with the first positioning block. The second connecting segment of the second fisheye pin is embedded into the circuit connection hole of the ceramic core. S2. Sub-component assembly: The automated insertion mechanism picks up the circuit board delivered by the automated feeding mechanism, inserts the circuit through hole of the circuit board into the second fisheye segment of the second fisheye PIN, then picks up the assembled connector, faces the circuit board with the inner side, and inserts the first fisheye segment of the first fisheye PIN into the corresponding circuit through hole of the circuit board, so that the circuit board, ceramic core, and the first and second fisheye PINs can achieve mechanical locking and electrical connection without soldering at room temperature. S3. Testing and Calibration: The electrical path between the first and second fisheye pins and the circuit board and ceramic core is tested by an automated testing device. If the connection resistance meets the preset standard, the sensor assembly is completed and the sensor enters the subsequent packaging or calibration process. S4. Housing Encapsulation: The detection housing is temporarily fixed to the preset position of the assembly fixture by the automated feeding mechanism. The inner sealing ring is placed into the pressure sensing chamber by the automated assembly mechanism, and the axis of the inner sealing ring is aligned with the center of the fluid channel. An automated mating mechanism picks up a connector containing a circuit board and a ceramic core, embeds the inner side of the connector into the pressure-sensing cavity of the probe housing, and applies and cures RTV adhesive at the joint between the probe housing and the connector through an automated dispensing process, thus completing the sealing of the internal electrical unit.

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