Through needle temperature and pressure sensor and assembly process

Abstract

The invention discloses a through needle temperature and pressure sensor and an assembly process, and relates to the technical field of temperature and pressure sensors, and the sensor comprises a ceramic pressure core body and an NTC assembly. An NTC (Negative Temperature Coefficient) through needle for outputting a temperature signal is arranged on the ceramic pressure core body in a penetrating manner; the NTC assembly comprises an NTC chip, a lead wire sleeve, a fixing seat and a metal sheath, a lead wire of the NTC chip is sleeved in the lead wire sleeve and extends out to be arranged through the fixing seat, and the metal sheath is sleeved outside the lead wire sleeve and the NTC chip and is fixed on the fixing seat; the lead of the NTC chip is connected with the NTC through pin through electric resistance welding, so that the connection reliability is improved, and meanwhile, the soldering tin rosin is prevented from sputtering to pollute the fixed seat and the ceramic pressure core body; the structure of the temperature pressure sensor is simplified, the reliability of electric connection is improved, and a signal path is rationalized through lead wire arrangement, metal sheath protection and electric resistance welding direct connection; the problems of complex structure, circuit virtual connection and low reliability of the existing temperature and pressure sensor are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of temperature and pressure sensor technology, and in particular to a through-needle temperature and pressure sensor and its assembly process. Background Technology

[0002] Existing temperature and pressure sensors generally employ a ceramic capacitor core and a metal diaphragm to form the pressure sensing unit, and an NTC or thermistor to form the temperature acquisition unit. Signal transmission is then achieved via a flexible circuit board, metal probes, or leads. However, with the trend towards multi-parameter integration, existing solutions generally face problems such as complex structure, numerous sealing points, insufficient mechanical strength, and unreliable temperature probe installation.

[0003] Existing technical solutions mostly employ the following four structures: One uses a ring-shaped ceramic capacitor core, with the temperature sensing element passing through a central hole in the core and forming independent pressure chambers in the inner and outer rings. Due to the limited internal cavity, this structure requires an extremely thin metal diaphragm to ensure sufficient deformation space, significantly reducing strength and fatigue reliability. Furthermore, this solution transmits temperature signals via solder joints and wire perforations, lacking effective wire fixing measures. Long-term exposure to vehicle vibration or pressure pulse impacts can easily cause the solder joints to loosen and fail. In addition, this solution uses up to three static sealing rings, which age rapidly under temperature cycling and medium pressure fluctuations, resulting in a high risk of leakage.

[0004] The structure employs a metal sleeve connected to the temperature element carrier via press-fitting or heat-fitting, and uses multiple sealing rings to achieve radial sealing before being packaged with a ceramic capacitor core and a flexible circuit board. In this design, the temperature pins are exposed, making them susceptible to corrosion and contamination. The riveting process of the metal sleeve can also cause localized stress concentration on the plastic or metal carrier, reducing overall durability. Furthermore, the cavity between the metal sleeve and the temperature element limits the thermal response speed, and the sleeve is prone to plastic deformation under high pressure, compressing the sealing rings and leading to seal failure.

[0005] A flexible circuit board is used to connect the ceramic core and the NTC component. Three sealing rings ensure the system's airtightness, and the metal protective sleeve is connected to the sensor housing using laser welding or TIG welding. Its disadvantages include a complex multi-sealing structure and the increased risk of seal failure due to wear and tear over long-term operation; the heat-affected zone created by the hot welding process may alter material properties and cause stress concentration in the welded area, affecting structural reliability.

[0006] A ceramic substrate and a diaphragm are laminated to form a through-channel, and the temperature component is encapsulated with epoxy after being soldered through pins. However, the soldering process has limited bonding strength between the pins and the through pins, and it is prone to rosin contamination. Over long-term use, this may cause loose solder joints, resistance drift, or aging of the sealing interface, thereby affecting the temperature acquisition accuracy and the overall lifespan of the sensor.

[0007] In summary, the existing technology has at least the following technical problems: Existing temperature and pressure sensors suffer from technical problems such as complex structure, poor reliability, loose circuit connections, and unreasonable circuit paths, resulting in low sealing reliability, low durability, and signal distortion. Summary of the Invention

[0008] The purpose of this invention is to provide a through-needle temperature and pressure sensor and its assembly process to solve the technical problems of existing temperature and pressure sensors, such as complex structure, poor reliability, loose circuit connections, and unreasonable circuit paths, which lead to low sealing reliability, low durability, and signal distortion.

[0009] 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.

[0010] To address the aforementioned technical problems, the present invention provides the following technical solution: This invention provides a through-needle temperature and pressure sensor, comprising a ceramic pressure core and an NTC assembly; an NTC through-needle for temperature signal output is inserted through the ceramic pressure core; the NTC assembly includes an NTC chip, a lead sleeve, a mounting base, and a metal sheath; the NTC chip is located at one end of the lead sleeve, and the lead of the NTC chip is sleeved inside the lead sleeve and extends out of the other end of the lead sleeve according to the shape of the lead sleeve; the lead sleeve is mounted on the mounting base and straightens the lead of the NTC chip inside the mounting base; the metal sheath is sleeved on the lead sleeve and the NTC chip and fixed on the mounting base; the lead of the NTC chip is connected to the end of the NTC through-needle facing the mounting base by resistance welding, so as to achieve sputter-free welding of the lead between the mounting base and the ceramic pressure core and the NTC through-needle.

[0011] In one embodiment, the ceramic pressure core includes either a resistive pressure core or a capacitive pressure core.

[0012] In one embodiment, the ceramic pressure core is further provided with a PIN pin for pressure signal output; the other end of the PIN pin and the NTC pin are both used to connect to the circuit board to be installed, for outputting pressure signal and temperature signal to the circuit board.

[0013] In one embodiment, thermally conductive adhesive is injected between the NTC chip and the metal sheath to bond the mounting base and the metal sheath, thereby improving temperature sensing sensitivity and providing buffer protection for the NTC chip.

[0014] In one embodiment, the solder joint where the NTC chip leads are soldered to the NTC pins is filled with potting compound to encapsulate and cure the solder joint, thereby improving the stability of the solder joint connection and the reliability of conduction.

[0015] In one embodiment, the mounting base is provided with two oppositely arranged potting grooves, which cover the leads of the NTC chip extending from the lead sleeve and the metal sheath, and the solder joints where the leads of the NTC chip are soldered to the NTC pins; the potting grooves connect the space enclosed by the mounting base and the ceramic pressure core; the potting adhesive is injected into the potting grooves and the space enclosed by the mounting base and the ceramic pressure core to seal the mounting base and bond the mounting base to the ceramic pressure core.

[0016] In one embodiment, the mounting base is provided with two opposing pressure channels. Under the sealing protection of the NTC chip, the NTC chip lead and the NTC pin solder joint, the liquid or gas whose pressure needs to be measured is introduced into the finished shell to be installed through the pressure channels to the measuring side of the ceramic pressure core.

[0017] In one embodiment, the fixing base has a vertically upward-extending positioning post at the center of its axis facing the metal sheath. The sidewall of the positioning post has opposingly arranged protruding fasteners, and the sidewall of the corresponding protruding fastener on the metal sheath also has a fastening hole. A mounting cavity is located at the axis of the positioning post, and two opposing mounting grooves are located on the sidewall of the positioning post, communicating with the mounting cavity. The lead sleeve is fitted inside the mounting cavity, and the lead of the NTC chip extends through the mounting groove and enters the potting groove. The metal sheath is fitted over the positioning post, and the protruding fasteners extend out of the fastening holes corresponding to their positions, forming a snap-fit ​​positioning structure. This snap-fit ​​positioning structure connects and fixes the metal sheath to the fixing base, thereby improving the stability of the metal sheath in protecting the NTC chip.

[0018] In one embodiment, a wing plate that opens obliquely outward is provided in the vertical direction outside the buckle hole of the metal sheath. The wing plate is integrally stamped with the outer wall of the metal sheath. When the finished shell is installed on the metal sheath, the wing plate contacts the finished shell to form a ground, thereby improving the stability and accuracy of the temperature signal output by the NTC chip through the lead wire. An assembly process for a through-needle temperature and pressure sensor is also provided, including the through-needle temperature and pressure sensor, comprising the following steps: S1, inserting the NTC chip and leads into the lead sleeve, and installing the lead sleeve on the fixing base, so that the leads of the NTC chip are properly positioned in the fixing base. S2. Inject thermally conductive adhesive between the NTC chip and the metal sheath to bond, fix, and buffer the NTC chip. S3. Place the metal sheath over the lead sleeve and connect and fix the metal sheath to the fixing seat through the snap-fit ​​structure, and then fill with potting compound. S4. Mount the mounting base to the ceramic pressure core, arranging one end of the NTC pin and the PIN pin on the ceramic pressure core toward the direction of the circuit board to be installed. S5. The leads of the NTC chip are soldered to the other end of the NTC pin on the ceramic pressure core using resistance soldering. S6. Inject potting compound into the potting tank to cover the solder joints of the NTC chip leads and the space enclosed by the mounting base and the ceramic pressure core, and cure to form a secondary sealing layer to complete the assembly of the through needle temperature and pressure sensor.

[0019] The beneficial effects of this invention are as follows: First, the present invention adopts a separate structure of ceramic pressure core and NTC component, and an NTC pin for temperature signal output is inserted on the ceramic pressure core, so that the temperature acquisition path and the pressure acquisition path are independent of each other. This avoids the problems of structural complexity, wiring difficulties and diaphragm space limitation caused by the temperature lead being laid through narrow cavity in the traditional ring ceramic core, thereby improving the overall structural stability.

[0020] Secondly, by setting up lead sleeves and fixing bases, the present invention effectively regulates and limits the NTC chip leads before they enter the soldering area, avoiding the risk of poor connection caused by leads being suspended, twisted, or vibrating, and significantly improving the stability of temperature signal output; the double-layer protection structure of lead sleeves and metal sheaths further enhances the mechanical protection capability and durability of the leads.

[0021] Furthermore, this invention employs resistance welding to solder the NTC chip leads to the NTC pins of the ceramic pressure core. Resistance welding does not produce metal sputtering, significantly reducing the risk of solder joint contamination of the ceramic core electrode surface or internal cavity compared to traditional tin soldering. At the same time, it has high welding strength and good solder joint consistency, effectively improving the reliability of electrical connections between electronic components within the temperature and pressure sensor and avoiding signal distortion caused by solder joint detachment or poor soldering.

[0022] In addition, a metal sheath is fitted over the lead wire sleeve and NTC chip and fixed to the mounting base, providing overall rigid protection for the NTC chip and improving its impact and vibration resistance. This structure makes the temperature acquisition path more reasonable and clear, effectively avoiding the hidden dangers of leakage, corrosion or short circuit caused by exposed leads, thereby significantly improving the service life and safety of the sensor.

[0023] In summary, this invention successfully solves the problems of complex structure, poor sealing reliability, loose circuit connection, and signal distortion in existing temperature and pressure sensors by using a regular lead sleeve structure, resistance welding process, metal sheath protection structure, and through-needle temperature signal lead-out method. It achieves comprehensive technical improvement in temperature and pressure sensors in terms of high reliability, simplified structure, improved durability, and enhanced signal stability. Attached Figure Description

[0024] 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.

[0025] Figure 1 This is an isometric structural diagram of the needle temperature and pressure sensor of the present invention; Figure 2 This is a front view structural diagram of the assembly of the through-needle temperature and pressure sensor and circuit board of the present invention; Figure 3 This is a top view schematic diagram of the through-needle temperature and pressure sensor of the present invention; Figure 4 This is a bottom view of the structure of the needle temperature and pressure sensor of the present invention; Figure 5 This is a perspective view of the needle temperature and pressure sensor of the present invention.

[0026] The reference numerals in the attached figures are as follows: 1. Ceramic pressure core; 11. NTC probe; 12. PIN pin; 13. Measuring side; 2. NTC component; 3. NTC chip; 31. Lead wire; 4. Lead wire sleeve; 5. Fixing base; 51. Filling groove; 52. Pressure channel; 53. Positioning post; 531. Protruding fastener; 532. Mounting cavity; 533. Mounting groove; 6. Metal sheath; 61. Buckle hole; 62. Wing plate; 7. Circuit board. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0028] This embodiment provides a through-needle temperature and pressure sensor and its assembly process. The sensor includes a ceramic pressure core and an NTC assembly. An NTC through-needle for temperature signal output is inserted through the ceramic pressure core. The NTC assembly includes an NTC chip, a lead sleeve, a mounting base, and a metal sheath. The lead of the NTC chip is sleeved inside the lead sleeve and extends out and is neatly arranged by the mounting base. The metal sheath is sleeved outside the lead sleeve and the NTC chip and fixed to the mounting base. The lead of the NTC chip is connected to the NTC through-needle by resistance welding to avoid welding sputtering contaminating the ceramic pressure core. Through lead neatness, metal sheath protection, and resistance welding connection, the temperature and pressure sensor structure is simplified, the electrical connection reliability is improved, and the signal path is rationalized. This effectively solves the technical problems of existing temperature and pressure sensors, such as complex structure, poor sealing reliability, loose circuit connections, and unreasonable circuit paths, which lead to low sealing reliability, low durability, and signal distortion.

[0029] The first implementation of the needle temperature and pressure sensor, for example Figures 1 to 5 As shown, the device includes a ceramic pressure core 1 and an NTC assembly 2. An NTC probe 11 for temperature signal output is mounted on the ceramic pressure core 1. The NTC assembly 2 includes an NTC chip (Negative Temperature Coefficient) 3, a lead sleeve 4, a mounting base 5, and a metal sheath 6. The NTC chip 3 is located at one end of the lead sleeve 4, and the lead 31 of the NTC chip 3 is fitted inside the lead sleeve 4 and extends out of the other end of the lead sleeve 4 according to its regular shape. The lead sleeve 4 is mounted on the mounting base 5, and the lead 31 of the NTC chip 3 is neatly aligned within the mounting base 5. The metal sheath 6 is fitted over the lead sleeve 4 and the NTC chip 3 and fixed to the mounting base 5. The lead 31 of the NTC chip 3 is welded to the end of the NTC probe 11 facing the mounting base 5 via resistance welding, achieving sputter-free welding of the lead 31 between the mounting base 5 and the ceramic pressure core 1 and the NTC probe 11.

[0030] This technical solution provides a through-needle temperature and pressure sensor that addresses the problems of complex structure, poor sealing reliability, loose circuit connections, and unreasonable circuit paths in existing temperature and pressure sensors. Through structural simplification, path optimization, and improved welding processes, it achieves several technical effects to improve the stability, reliability, and sealing of the temperature and pressure sensor. Specific technical effects include: First, this technical solution adopts a separate structure of ceramic pressure core 1 and NTC component 2, and an NTC through-needle 11 for temperature signal output is threaded through the ceramic pressure core 1. This makes the temperature acquisition path and pressure acquisition path independent of each other, avoiding the structural complexity, wiring difficulties, and diaphragm space limitations caused by the temperature lead 31 being laid through narrow cavities in traditional annular ceramic cores, thereby improving the overall structural stability.

[0031] Secondly, by setting the lead sleeve 4 and the fixing base 5, this technical solution effectively regulates and limits the lead 31 of the NTC chip 3 before it enters the soldering area, avoiding the risk of poor connection caused by the lead 31 being suspended, twisted, or vibrating, and significantly improving the stability of the temperature signal output. The double-layer protection structure of the lead sleeve 4 and the metal sheath 6 further enhances the mechanical protection capability and durability of the lead 31.

[0032] Furthermore, this technical solution uses resistance welding to weld the NTC chip 3 lead 31 to the NTC pin 11 of the ceramic pressure core 1. Resistance welding does not produce metal sputtering, which significantly reduces the risk of solder joint contamination of the ceramic core electrode surface or internal cavity compared to traditional tin soldering. At the same time, the welding strength is high and the solder joint consistency is good, which effectively improves the reliability of the electrical connection between electronic components in the temperature and pressure sensor and avoids signal distortion caused by solder joint detachment or poor soldering.

[0033] In addition, the metal sheath 6 is fitted over the lead sleeve 4 and the NTC chip 3 and fixed to the mounting base 5, which provides overall rigid protection for the NTC chip 3 and improves its impact resistance and vibration resistance. This structure makes the temperature acquisition path more reasonable and clear, effectively avoiding the hidden dangers of leakage, corrosion or short circuit caused by exposed lead 31, thereby significantly improving the service life and safety of the sensor.

[0034] In summary, this technical solution, through the regular structure of the lead sleeve 4, the resistance welding process, the protective structure of the metal sheath 6, and the through-needle temperature signal lead-out method, successfully solves the problems of complex structure, poor sealing reliability, circuit connection and signal distortion in existing temperature and pressure sensors, and achieves comprehensive technical improvement in temperature and pressure sensors in terms of high reliability, simplified structure, improved durability and signal stability.

[0035] As one alternative implementation method: Regarding the electrical connection structure of the aforementioned ceramic pressure core 1, this embodiment is, for example... Figures 1 to 5As shown, the ceramic pressure core 1 is also provided with a PIN needle 12 for pressure signal output; the other end of the PIN needle 12 and the NTC pin 11 are both used to connect to the circuit board 7 to be installed, and to output pressure signal and temperature signal to the circuit board 7.

[0036] In application, the PIN pins 12 and NTC pins 11 on the ceramic pressure core 1 are arranged facing the circuit board 7 to be installed, so that the pressure signal path and the temperature signal path are structurally independent but achieve co-directional output on the external interface side. This structure allows the sensor to be installed into the finished housing with only one alignment soldering or plug-in connection, avoiding the wiring mess and unreasonable circuit path problems caused by the temperature lead 31 being wound from the side or passing through the internal cavity in traditional solutions.

[0037] By evenly distributing the PIN pins 12 and NTC pins 11 on one side of the ceramic pressure core 1 and the circuit board 7, the signal path can be minimized and made as straight as possible, significantly reducing signal loss and interference, improving the integrity and accuracy of temperature and pressure signals during transmission, and thus enhancing the overall control response performance of the machine.

[0038] The PIN pin 12 and NTC through pin 11 are made of gold-plated, tin-plated or nickel-plated metal materials to further improve solderability and oxidation resistance; the connection between the PIN pin 12 and the ceramic pressure core 1 also adopts a co-fired embedded structure to improve the thermal shock resistance of the body connection.

[0039] Regarding the measurement type used in the aforementioned ceramic pressure core 1, the ceramic pressure core 1 includes either a resistive pressure core or a capacitive pressure core.

[0040] When applying the technology, depending on the requirements of different application scenarios for pressure response speed, range and anti-interference performance, the ceramic pressure core 1 can be configured as a resistive pressure core or a capacitive pressure core.

[0041] Capacitive cores have high sensitivity and low temperature drift, making them suitable for stable operating conditions such as home appliances and fluid control; while resistive cores have higher mechanical strength and impact resistance, making them more suitable for operating conditions with strong pressure pulses, such as automobiles and industrial equipment.

[0042] By modularly changing the pressure core type, the entire temperature and pressure sensor can expand its application scenarios during the assembly stage without changing the temperature acquisition path and structural layout. While ensuring that the temperature detection part remains unchanged, it is compatible with various pressure detection needs, thereby improving the sensor's serialization and versatility.

[0043] Regarding the protective structure of the aforementioned NTC chip 3, this implementation is, for example... Figures 1 to 5As shown, thermally conductive adhesive is injected between the NTC chip 3 and the metal sheath 6 to bond the mounting base 5 and the metal sheath 6, thereby improving the temperature measurement sensitivity and providing buffer protection for the NTC chip 3.

[0044] When applied, thermally conductive adhesive is injected between the NTC chip 3 and the metal sheath 6, so that the NTC chip 3 can obtain reliable mechanical support while forming a continuous heat conduction path.

[0045] The thermally conductive adhesive not only rapidly transfers external temperature to the NTC chip 3, thereby improving temperature sensing sensitivity and response speed, but also provides buffering protection for the NTC chip 3 under conditions such as vibration and drops, preventing the lead wire 31 from bending and breaking or the chip from falling off due to stress concentration. Simultaneously, the thermally conductive adhesive bonds the mounting base 5 to the metal sheath 6, ensuring the overall structural stability of the NTC chip 3 and forming a double-layer protection system with the subsequent potting compound, achieving a higher level of reliability. This structure effectively solves the problems of cavity response hysteresis and high vibration sensitivity existing in traditional metal sleeves.

[0046] The thermally conductive adhesive uses silicone, epoxy resin or flexible high thermal conductivity materials, and its thermal conductivity is selected between 1-4 W / m·K depending on the application environment to adapt to different temperature response requirements.

[0047] Regarding the solder joint protection structure for the lead 31 and NTC pin 11 of the aforementioned NTC chip 3, this embodiment is, for example... Figures 1 to 5 As shown, the solder joint where the lead 31 of the NTC chip 3 is soldered to the NTC pin 11 is filled with potting compound. The potting compound is used to encapsulate and cure the solder joint to protect it, thereby improving the stability of the solder joint connection and the reliability of conduction.

[0048] Specifically, the mounting base 5 is provided with two oppositely arranged potting grooves 51, which cover the leads 31 of the NTC chip 3 extending from the lead sleeve 4 and the metal sheath 6, as well as the solder joints where the leads 31 of the NTC chip 3 are soldered to the NTC pin 11; the potting grooves 51 connect the space enclosed by the mounting base 5 and the ceramic pressure core 1; potting compound is injected into the potting grooves 51 and the space enclosed by the mounting base 5 and the ceramic pressure core 1 to seal the mounting base 5 and bond the mounting base 5 and the ceramic pressure core 1.

[0049] During application, the solder joints of the NTC chip 3's lead 31 and the NTC probe 11 are completely encapsulated with potting compound. After curing, the potting compound forms a high-strength secondary sealing layer, effectively preventing moisture, oil, and corrosive gases from eroding the solder joints. The potting compound applies mechanical restraint to the solder joints, ensuring stable electrical connection under operating vibration and thermal cycling, avoiding risks such as poor soldering, cracks, or solder joint detachment. Simultaneously, the potting groove 51 on the mounting base 5 communicates with the space formed by the ceramic pressure core 1, allowing the potting compound to perform sealing, fixing, and buffering functions after curing, further enhancing the mechanical strength and sealing reliability of the entire temperature acquisition path and solving problems such as leakage, corrosion, and signal drift caused by exposed solder joints in existing technologies.

[0050] The potting compound can be made of flame-retardant epoxy, silicone or polyurethane materials, and reinforcing fillers or moisture-proofing agents can be added according to application requirements to improve the environmental adaptability of the needle temperature and pressure sensor.

[0051] Regarding the structure and function of the pressure channel 52 provided on the aforementioned fixed base 5, this embodiment is, for example... Figures 1 to 5 As shown, the mounting base 5 is provided with two opposing pressure channels 52. Under the sealing protection of thermally conductive adhesive and potting compound, the liquid or gas whose pressure needs to be measured is introduced into the finished shell to be installed through the pressure channels 52 to the measuring side 13 of the ceramic pressure core 1.

[0052] The pressure channel 52 and the potting tank 51 are set independently. The pressure channel 52 is surrounded by a channel wall, which prevents the potting adhesive from entering the independently set pressure channel 52 and avoids the potting adhesive from sealing the pressure channel 52.

[0053] In application, the pressure channels 52 arranged on the mounting base 5 are used to evenly introduce the pressure medium entering from outside the finished product casing into the measuring side 13 of the ceramic pressure core 1. At the same time, the pressure channels 52 are isolated from the areas protected by thermally conductive adhesive and potting compound, so that the NTC chip 3, the NTC chip 3 leads 31 and their solder joints do not directly contact the pressure medium being measured. This structure makes the pressure channels 52 clearly oriented and minimizes resistance, avoiding the response lag, pressure loss or local compression caused by the detour of the pressure path in traditional structures, thus improving the accuracy of pressure measurement.

[0054] By using thermally conductive adhesive and potting compound to create a double seal in the NTC area, the NTC chip 3 is protected from interference from pressurized liquids or gases in terms of temperature acquisition and electrical connection, thus enabling the temperature and pressure measurement functions to be independent of each other and not affect each other.

[0055] Regarding the specific structure of the connection between the aforementioned mounting bracket 5 and the NTC chip 3's lead 31, lead sleeve 4, and metal sheath 6, this embodiment is, for example... Figures 1 to 5 As shown, a vertically upward-extending positioning post 53 is provided on the center of the axis of the fixing base 5 facing the metal sheath 6. The side wall of the positioning post 53 is provided with oppositely arranged protruding fasteners 531. The side wall of the corresponding protruding fastener 531 of the metal sheath 6 is also provided with a fastening hole 61. A mounting cavity 532 is provided at the axis of the positioning post 53. Two oppositely arranged mounting grooves 533 are provided on the side wall of the positioning post 53. The mounting grooves 533 are connected to the mounting cavity 532. The mounting sleeve 4 is fitted inside the mounting cavity 532. The lead wire 31 of the NTC chip 3 extends out through the mounting groove 533 and enters the potting groove 51. The metal sheath 6 is fitted outside the positioning post 53. The protruding fasteners 531 extend out of the fastening holes 61 corresponding to their positions, forming a snap-fit ​​positioning structure. The snap-fit ​​positioning structure connects and fixes the metal sheath 6 to the fixing base 5, thereby improving the stability of the metal sheath 6 in protecting the NTC chip 3.

[0056] When applied, the positioning post 53, mounting cavity 532, mounting groove 533 on the fixed base 5 and the snap hole 61 of the metal sheath 6 form a multi-point limiting structure, so that a stable mechanical connection is established between the NTC chip 3, the lead sleeve 4 and the metal sheath 6.

[0057] The mounting cavity 532 is used to install the lead sleeve 4, providing axial and radial limiting for the lead sleeve 4; the mounting groove 533 provides an exit path for the lead 31 of the NTC chip 3; the protruding buckle 531 on the positioning post 53 and the buckle hole 61 of the metal sheath 6 form a snap-fit ​​structure, realizing the quick assembly and firm fixation of the metal sheath 6 and the fixing base 5; through this structure, the lead 31 of the NTC chip 3 will not experience swaying or tensile stress due to vibration, operation, or pressure impact during the entire operation of the needle temperature and pressure sensor, ensuring the stability of the temperature signal acquisition path. This structure also simplifies the manufacturing process, reduces assembly difficulty, and helps improve the quality consistency of mass-produced needle temperature and pressure sensors.

[0058] A second implementation of the through-needle temperature and pressure sensor, for example Figure 5 As shown, the difference between this embodiment and the first embodiment is that a wing plate 62 that opens obliquely outward is provided in the vertical direction outside the buckle hole 61 of the metal sheath 6. The wing plate 62 is a structure that is integrally stamped with the outer wall of the metal sheath 6. When the finished shell is installed outside the metal sheath 6, the wing plate contacts the finished shell to form grounding, so as to improve the stability and accuracy of the temperature signal output by the NTC chip 3 through the lead 31.

[0059] In application, the metal sheath 6 has an integrally stamped wing plate 62 outside the buckle hole 61. After the sensor is assembled to the metal casing, the wing plate 62 can automatically and elastically fit against the inner wall of the metal casing, forming a stable grounding point. Through this structure, the static charge on the metal casing can be effectively and quickly discharged, preventing static electricity from affecting the weak temperature signal output by the lead 31 of the NTC chip 3.

[0060] The presence of the flying wing plate 62 can also form a local electromagnetic shielding effect, reducing the interference of surrounding electromagnetic noise on the temperature signal line and improving the accuracy and stability of the temperature signal output. This solution avoids the complicated process of needing to separately weld the grounding wire or set up additional grounding contacts in the traditional solution, making the structure simpler, the cost lower and the reliability higher.

[0061] Based on the above embodiments of the through-needle temperature and pressure sensor, an assembly process for the through-needle temperature and pressure sensor is provided, including the following steps, including the following steps in the order of S1 to S6: S1, insert the NTC chip and leads into the lead sleeve, and install the lead sleeve on the fixing base, so that the leads of the NTC chip are neatly positioned in the fixing base. S2. Inject thermally conductive adhesive between the NTC chip and the metal sheath to bond, fix, and buffer the NTC chip. S3. Place the metal sheath over the lead sleeve and connect and fix the metal sheath to the fixing seat through the snap-fit ​​structure, and then fill with potting compound. S4. Mount the mounting base to the ceramic pressure core, arranging one end of the NTC pin and the PIN pin on the ceramic pressure core toward the direction of the circuit board to be installed. S5. The leads of the NTC chip are soldered to the other end of the NTC pin on the ceramic pressure core using resistance welding. S6. Inject potting compound into the potting tank to cover the solder joints of the NTC chip leads and the space enclosed by the mounting base and the ceramic pressure core, and cure to form a secondary sealing layer to complete the assembly of the through needle temperature and pressure sensor.

[0062] In application, the assembly process of the through-needle temperature and pressure sensor involves sequentially executing steps S1 to S6, which allows the NTC chip for temperature acquisition, the ceramic pressure core for pressure acquisition, and their electrical connection structure to be solidly formed step by step.

[0063] First, by placing the NTC chip's leads inside the lead sleeve in step S1 and then aligning them secondary by the fixing seat, the temperature signal path can be dually limited in both the axial and radial directions before soldering, avoiding problems such as lead twisting, suspension, or force displacement that are common in traditional bare wire structures.

[0064] In addition to forming a continuous heat conduction path, the thermally conductive adhesive injection in step S2, together with the metal sheath and mounting base, forms a buffer coating layer for the NTC chip, ensuring that the chip remains in its correct position and is not damaged even under pressure pulses, vibrations, or drops.

[0065] In step S3, the snap-fit ​​structure of the metal sheath cooperates with the positioning post and protruding block of the fixing seat to form a high-strength mechanical skeleton on the outside of the NTC chip, providing a structural stability basis for subsequent glue injection curing and welding.

[0066] In step S4, the mounting of the fixing base and the ceramic pressure core further forms a unified direction for signal output, aligning the PIN pins and NTC pins in the arrangement, providing a convenient and stable docking method for the assembly of the entire circuit board.

[0067] The resistance welding connection method in step S5, together with the aforementioned measures of neat lead wires and stable structure, ensures that the weld joint is subjected to uniform force and is not affected by the swing of the metal sheath or lead wires, thereby improving the welding quality and avoiding sputtering contamination of the ceramic pressure core.

[0068] Finally, step S6 seals and cures the solder joints and mounting gaps with potting compound, completely isolating the temperature acquisition path from the pressure channel, forming a secondary sealing structure, which significantly improves the sealing reliability, environmental resistance and long-term stability of the whole machine.

[0069] The gradual implementation of the overall process not only avoids problems such as multiple sealing ring failures, loose welds, and structural loosening in traditional solutions, but also achieves a highly reliable, low-complexity manufacturing method for needle temperature and pressure sensors that is suitable for automated mass production through the synergistic optimization of structure and process.

[0070] 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 needle temperature and pressure sensor, characterized in that, Including ceramic pressure cores and NTC components; The ceramic pressure core is equipped with an NTC probe for temperature signal output. The NTC component includes an NTC chip, a lead sleeve, a mounting base, and a metal sheath; The NTC chip is located at one end of the lead sleeve, and the leads of the NTC chip are sleeved inside the lead sleeve and extend out of the other end of the lead sleeve in a regular shape. The lead sleeve is installed on the mounting base and the leads of the NTC chip are aligned into the mounting base; The metal sheath is fitted over the lead sleeve and the NTC chip and fixed to the mounting base; The leads of the NTC chip are connected to the end of the NTC probe facing the mounting base by resistance welding, so as to achieve sputter-free welding of the leads and the NTC probe between the mounting base and the ceramic pressure core.

2. The needle temperature and pressure sensor according to claim 1, characterized in that, The ceramic pressure core includes either a resistive pressure core or a capacitive pressure core.

3. The needle temperature and pressure sensor according to claim 1, characterized in that, The ceramic pressure core is also provided with a PIN pin for pressure signal output; The other end of both the PIN pin and the NTC pin is used to connect to the circuit board to be installed, and to output pressure signals and temperature signals to the circuit board.

4. The needle temperature and pressure sensor according to claim 1, characterized in that, Thermally conductive adhesive is injected between the NTC chip and the metal sheath to bond the mounting base and the metal sheath, thereby improving temperature measurement sensitivity and providing buffer protection for the NTC chip.

5. The needle temperature and pressure sensor according to claim 4, characterized in that, The solder joints where the leads of the NTC chip are soldered to the NTC pins are filled with potting compound. The potting compound is used to encapsulate and cure the solder joints, thereby improving the stability of the solder joint connection and the reliability of conduction.

6. The needle temperature and pressure sensor according to claim 5, characterized in that, The mounting base is provided with two oppositely arranged potting grooves, which cover the leads of the NTC chip extending from the lead sleeve and the metal sheath, as well as the solder joints where the leads of the NTC chip are soldered to the NTC pins. The potting groove connects to the space enclosed by the fixing seat and the ceramic pressure core; The potting compound is injected into the potting groove and the space enclosed by the fixing seat and the ceramic pressure core to seal the fixing seat and bond the fixing seat and the ceramic pressure core.

7. The needle temperature and pressure sensor according to claim 6, characterized in that, The mounting base is provided with two opposing pressure channels. Under the sealing protection of the NTC chip, the NTC chip lead and the NTC pin solder joint, the liquid or gas whose pressure needs to be measured is introduced into the finished shell to be installed and then introduced into the measuring side of the ceramic pressure core through the pressure channels.

8. The needle temperature and pressure sensor according to claim 6, characterized in that, The fixing base has a vertically upward extending positioning post at the center of the axis facing the metal sheath. The side wall of the positioning post has oppositely arranged protruding fasteners, and the side wall of the corresponding protruding fastener of the metal sheath also has a fastening hole. The positioning post has a mounting cavity at its axis and two oppositely arranged mounting grooves on its side wall, which communicate with the mounting cavity. The lead sleeve is fitted into the mounting cavity, and the NTC chip's lead extends through the mounting groove and enters the potting groove. The metal sheath is fitted over the positioning post, and the protruding buckle extends out of the buckle hole corresponding to the buckle hole, forming a snap-fit ​​positioning structure. The snap-fit ​​positioning structure connects and fixes the metal sheath to the fixing base, thereby improving the stability of the metal sheath in protecting the NTC chip.

9. The needle temperature and pressure sensor according to claim 8, characterized in that, The metal sheath has a wing plate that opens obliquely outward in the vertical direction outside the buckle hole. The wing plate is a structure that is integrally stamped with the outer wall of the metal sheath. When the finished housing is installed outside the metal sheath, the flying wing contacts the finished housing to form a ground, thereby improving the stability and accuracy of the temperature signal output by the NTC chip via the lead wire.

10. An assembly process for a needle temperature and pressure sensor, comprising the needle temperature and pressure sensor according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Insert the NTC chip and leads into the lead sleeve, and install the lead sleeve on the mounting base so that the NTC chip leads are properly positioned in the mounting base. S2. Inject thermally conductive adhesive between the NTC chip and the metal sheath to bond, fix, and buffer the NTC chip. S3. Place the metal sheath over the lead sleeve and connect and fix the metal sheath to the fixing base through the snap-fit ​​structure, and then fill with potting compound. S4. Mount the mounting base to the ceramic pressure core, arranging one end of the NTC pin and the PIN pin on the ceramic pressure core toward the direction of the circuit board to be installed. S5. The leads of the NTC chip are soldered to the other end of the NTC pin on the ceramic pressure core using resistance welding. S6. Inject potting compound into the potting tank to cover the solder joints of the NTC chip leads and the space enclosed by the mounting base and the ceramic pressure core, and cure to form a secondary sealing layer to complete the assembly of the through needle temperature and pressure sensor.

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