Electrical connector and brazing method for use in a high pressure environment box

Abstract

The application discloses a kind of electric connector and brazing method for high-pressure environment box, including vertical cylinder stainless steel outer shell, T-shaped stainless steel inner shell into stainless steel outer shell and with detachable connection in upper portion of stainless steel outer shell, silicon nitride ceramic round plate, M strip vertical copper core wire and copper core wire sleeve on the upper portion of the copper core wire, M is greater than or equal to 3;Upper end and lower end of stainless steel inner shell and stainless steel outer shell are both open, and stainless steel annular support frame is arranged in the middle of inner side surface of stainless steel outer shell, and the silicon nitride ceramic round plate is located on the stainless steel annular support frame;The application has the characteristics of good sealing performance of electric connector and long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal transmission connection, in particular to an electric connector used in a high-pressure environment box and a brazing method. BACKGROUND

[0002] With the continuous improvement of the performance requirements of materials and parts in modern industry, the application of high-pressure gas environment fatigue test tensile machines is becoming more and more critical. The above-mentioned equipment is mainly used to simulate the fatigue performance of materials or parts under the action of high-pressure gas environment and tensile stress, and to evaluate the reliability and service life of the materials or parts under complex working conditions.

[0003] The electric connector in the prior art is prone to deformation and cracking under high pressure, which can cause problems such as sealing failure, unstable signal, gas leakage, etc., hindering the performance research of materials and parts, leading to frequent equipment failure and test interruption, and causing high maintenance costs and waste of test materials. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the electric connector in the prior art, such as poor sealing performance under high pressure, easy failure of the welded part, and frequent interruption of signal transmission, and to provide an electric connector used in a high-pressure environment box and a brazing method.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] An electric connector used in a high-pressure environment box, comprising a vertical cylinder-shaped stainless steel outer shell, a T-shaped stainless steel inner shell extending into the stainless steel outer shell and being detachably connected to the upper part of the stainless steel outer shell, a silicon nitride ceramic round plate, M vertical copper core wires, and a copper core wire sleeve provided at the upper part of the copper core wire, M≥3; the upper end and the lower end of the stainless steel inner shell and the stainless steel outer shell are both open, a stainless steel annular support frame is provided on the inner side of the stainless steel outer shell in the middle, and the silicon nitride ceramic round plate is located on the stainless steel annular support frame; the silicon nitride ceramic round plate is provided with M through holes, an annular groove for accommodating solder is provided at the upper part of the through hole, the copper core wire passes through the corresponding through hole downward and is brazed with the corresponding through hole; a gap is provided between the inner side of the stainless steel annular support frame and the outer side of the silicon nitride ceramic round plate, and the inner side of the stainless steel annular support frame and the outer side of the silicon nitride ceramic round plate are brazed.

[0007] The copper core wire sleeve is used to provide electrical insulation protection for the copper core wire to prevent leakage and short circuit caused by the interlacing of the copper core wire current. The depth of the annular groove is generally set to 1.5mm, which can increase the welding area of the copper core wire and the silicon nitride ceramic round plate, and also increase the accumulation of solder, so that the plasticity of the solder can be used to reduce the stress at this point, so that the silicon nitride ceramic round plate and the copper core wire are sealed and connected.

[0008] The silicon nitride ceramic round plate used in the application has good insulation effect, so that the electric connector does not have a current leakage phenomenon when transmitting signals.

[0009] The gap can reduce the risk of cracking of the stainless steel outer shell, the stainless steel annular support frame and the nitrogenized silicon ceramic round plate caused by thermal expansion and extrusion, effectively reduce the welding internal stress caused by the brazing of the nitrogenized silicon ceramic round plate and the stainless steel annular support frame, store excess solder, and the plasticity of the solder can relieve part of the stress, effectively improve the sealing performance of the connector in extreme environments, ensure the stability of the welding part, prevent the gas in the high-pressure environment box from leaking out through the electric connector, significantly reduce the interruption of signal transmission, and prolong the service life of the connector.

[0010] Preferably, the copper core wire is provided with a mica ring gasket in the middle, and the upper surface of the silicon nitride ceramic round plate is provided with an annular groove for accommodating the mica ring gasket.

[0011] Preferably, the lower end of the stainless steel inner shell is provided with an annular plate made of stainless steel, the middle of the annular plate is provided with a stepped hole, and the stepped hole is provided with a silicon nitride ceramic sealing plate; the middle of the silicon nitride ceramic sealing plate is provided with M sealing holes, the sealing holes are provided with annular pits for accommodating the filler metal, the lower part of the copper core wire passes through the corresponding sealing hole and is brazed to the sealing hole; a gap is provided between the outer side of the silicon nitride ceramic sealing plate and the upper part of the inner side of the stepped hole, and the outer side of the silicon nitride ceramic sealing plate and the inner side of the stepped hole are brazed.

[0012] The annular plate and the silicon nitride ceramic sealing plate can further improve the sealing performance of the electric connector and prevent the gas in the high-pressure environment box from leaking out through the electric connector.

[0013] Preferably, the solder is composed of Ag, Cu, In metal powder and nano titanium oxide powder, and the mass fraction ratio of Ag, Cu, In metal powder and nano titanium oxide powder in the solder is (10-14):(4-6):(1-3):1.

[0014] The components are weighed according to the above-mentioned component ratio of the solder by using a high-precision electronic balance. The weighed Ag, Cu and In metal powders are put into the crucible of a vacuum induction melting furnace (the vacuum degree reaches more than 10-3 Pa), the crucible is vacuumized, and then high-purity argon is filled;

[0015] Using a vacuum induction melting furnace, the crucible is heated at a rate of 5℃ / min-10℃ / min until the temperature exceeds the alloy's melting point by 100℃-150℃, allowing all components to completely melt. After the temperature stabilizes, 1% of the total mass of each component of nano-TiO2 powder is weighed and slowly added to the molten metal. An electromagnetic stirrer is turned on, and the stirring speed is adjusted to 300rpm-400rpm, and stirring is continued for 5min-10min to ensure uniform dispersion of the nano-TiO2 powder in the molten metal. After stirring, the mixture is held at that temperature in the vacuum induction melting furnace for 10min-15min to achieve refining.

[0016] After refining, the molten metal is allowed to cool naturally to room temperature under argon gas. The cooled alloy ingot is then placed in a ball mill with a grinding ball to alloy ingot mass ratio of (5-8):1, and ball milled for 10-20 hours to obtain alloy powder with a particle size of 50-100 μm. Flux is added to the alloy powder according to a mass ratio of (8-9):1 between the alloy powder and flux (which contains rosin, activator, film-forming agent, etc.). The two are then placed in a mixer and stirred at 100-200 rpm for 15-30 minutes to ensure that the alloy powder and flux are fully mixed and homogeneous, thus producing solder.

[0017] Nano-titanium oxide is uniformly dispersed within the AgCuIn solder, resulting in more uniform diffusion of Ag, Cu, and In elements and reducing segregation. Ag enhances the bonding force with the copper core wire, while Cu improves the wettability with the ceramic block (silicon nitride ceramic disc or silicon nitride ceramic sealing plate), preventing deformation and cracking of the ceramic block caused by high residual stress during brazing, effectively improving the sealing performance of the electrical connector in extreme environments. In improves the wettability with (stainless steel annular support frame or inner surface of annular plate) and forms a dense reaction layer with Fe, Cr, etc., ensuring the stability of the soldered area, significantly reducing signal transmission interruptions and extending the service life of the electrical connector.

[0018] Preferably, the upper part of the inner side of the stainless steel outer shell is provided with an internal thread, and the outer side of the stainless steel inner shell is provided with an external thread, with the internal thread and the external thread meshing with each other; the lower part of the outer side of the stainless steel outer shell is provided with an installation thread.

[0019] The stainless steel outer shell and stainless steel inner shell of this invention are connected by a threaded fit, which facilitates flexible control of the filling depth of the mica ring gasket in the annular groove during assembly. This can effectively solve the problem of uneven stress on the silicon nitride ceramic disc under high pressure. The mica ring gasket does not need to be completely filled into the annular groove, which can be flexibly controlled to leave some floating space. The mica ring gasket can disperse the stress on the silicon nitride ceramic disc and further prevent the silicon nitride ceramic disc from deforming and cracking.

[0020] A brazing method for electrical connectors used in high-voltage environment enclosures includes the following steps:

[0021] Step 1-1, Pre-welding assembly:

[0022] Insert the copper core wire into the corresponding through hole, apply solder to the annular groove, and apply solder to the outer surface of the silicon nitride ceramic disc.

[0023] A silicon nitride ceramic disc is placed on a stainless steel annular support frame, allowing the copper core wire to pass through the lower end of the stainless steel lower housing, thus obtaining the assembly.

[0024] Steps 1-2, Vacuuming:

[0025] Place the hollow base at the bottom of the assembly, and then stand the assembly vertically in the vacuum brazing furnace. Use the three-stage pump of the vacuum brazing furnace to evacuate the furnace to a vacuum level of 10. -2 Below Pa;

[0026] Steps 1-3, Pre-welding heating:

[0027] The temperature inside the vacuum brazing furnace is raised from room temperature to T1, where T1 ranges from 240℃ to 250℃, the heating rate is 5℃ / min to 6℃ / min, and the holding time is 25min to 30min.

[0028] When the room temperature is raised to T1, the low-temperature solvent inside the solder can be effectively removed. The slow heating rate can ensure that the solvent inside the solder evaporates completely, while ensuring the thermal stability of the electrical connector and making the components of the electrical connector heat up evenly.

[0029] The temperature inside the vacuum brazing furnace is raised from T1 to T2, where T2 ranges from 550℃ to 600℃, the heating rate is 4.5℃ / min to 5℃ / min, and the holding time is 10min to 15min.

[0030] The process of heating from T1 to T2 can effectively remove the high-temperature solvent inside the solder. The slow heating rate can gradually evaporate the high-temperature solvent, ensuring that the solvent evaporates completely and does not affect subsequent soldering. At the same time, it ensures that the components of the electrical connector are heated evenly, preparing for the next heating step.

[0031] The temperature inside the vacuum brazing furnace is raised from T2 to T3, with T3 ranging from 700℃ to 750℃, at a heating rate of 4.5℃ / min to 5℃ / min, and held for 10 to 15 minutes.

[0032] The temperature is increased from T2 to T3. This process ensures that the components of the electrical connector are heated evenly at the stage close to the melting point of the solder. It avoids directly raising the temperature of the components at the soldering point, which would result in insufficient soldering and irreversible internal stress on the components, ultimately leading to cracking of the silicon nitride ceramic disc.

[0033] Steps 1-4: Perform brazing.

[0034] Step 1-4-1: Raise the temperature in the vacuum brazing furnace from T3 to T4. The value of T4 is in the range of 800℃-860℃, the heating rate is 1℃ / min-3℃ / min, and the holding time is 10min-15min.

[0035] Heating at a rate below 3℃ / min ensures uniform heating of the components in the electrical connector. If the heating is too rapid, the temperature of the silicon nitride ceramic disc will not keep up, resulting in uneven solder distribution.

[0036] Step 1-4-2: The solder melts and seals the copper core wire to the silicon nitride ceramic disc. The solder also seals the outer side of the silicon nitride ceramic disc to the stainless steel annular support frame.

[0037] Steps 1-5: Release internal stress:

[0038] The temperature inside the vacuum brazing furnace is reduced from T4 to T5, where T5 is in the range of 600℃-650℃, the cooling rate is >4℃ / min, and the holding time is 70min-80min.

[0039] This stage requires rapid cooling to reduce the continued reaction between the solder and the various components of the electrical connector;

[0040] Steps 1-6: Reduce the temperature inside the vacuum brazing furnace from T5 to room temperature, remove the assembly from the vacuum brazing furnace, and the brazing is complete.

[0041] Preferably, the copper core wire has a mica ring gasket in the middle, and the upper surface edge of the silicon nitride ceramic disc has an annular groove for accommodating the mica ring gasket; the process also includes the following electrical connector assembly process:

[0042] Place the mica ring gasket onto each copper core wire, allowing it to fall into the annular groove. Then, place a copper core wire sleeve on the upper part of each copper core wire. Insert the stainless steel inner shell into the upper part of the stainless steel outer shell, allowing the mica ring gasket to float along each copper core wire. This allows the copper core wire sleeve to extend beyond the upper end of the stainless steel inner shell, completing the electrical connector assembly.

[0043] Preferably, the lower end of the stainless steel inner shell is provided with a stainless steel annular plate, the annular plate has a stepped hole in the middle, and a silicon nitride ceramic sealing plate is provided on the stepped hole; the silicon nitride ceramic sealing plate has M sealing holes in the middle, and the sealing holes have annular pits for receiving brazing filler metal, the lower part of the copper core line passes through the corresponding sealing hole and is brazed to the sealing hole; there is a gap between the outer side of the silicon nitride ceramic sealing plate and the upper part of the inner side of the stepped hole, and the outer side of the silicon nitride ceramic sealing plate is brazed to the inner side of the stepped hole;

[0044] Step 1-1 is replaced by the following steps:

[0045] Solder is applied to the upper outer part of the silicon nitride ceramic sealing plate, and solder is applied to the annular pit. The silicon nitride ceramic sealing plate is then placed in the upper part of the stepped hole.

[0046] Solder is applied to the annular groove; solder is applied to the outer surface of the silicon nitride ceramic disc; the silicon nitride ceramic disc is placed on a stainless steel annular support frame, and the copper core wire is inserted into the corresponding through hole and sealing hole in sequence, so that the copper core wire passes through the lower end of the stainless steel lower housing to obtain the assembly.

[0047] Step 1-4-2 is replaced by the following steps:

[0048] The solder melts and seals the copper core wire to the silicon nitride ceramic disc. The solder seals the outer side of the silicon nitride ceramic disc to the stainless steel annular support frame. The solder seals the outer side of the silicon nitride ceramic sealing plate to the upper inner side of the stepped hole. The solder seals the copper core wire to the silicon nitride ceramic sealing plate.

[0049] The solder seals the outer side of the silicon nitride ceramic sealing plate to the upper part of the inner side of the stepped hole, and the solder seals the copper core wire to the silicon nitride ceramic disc, further ensuring the sealing performance of the electrical connector.

[0050] Therefore, the present invention has the following beneficial effects: no crosstalk occurs when transmitting signals, effectively improving the sealing performance of the electrical connector in extreme environments, ensuring the stability of the soldered parts, significantly reducing signal transmission interruptions, and improving the service life of the electrical connector. Attached Figure Description

[0051] Figure 1 This is a cross-sectional view of the present invention;

[0052] Figure 2 This is a cross-sectional view of the stainless steel inner shell of the present invention;

[0053] Figure 3 This is a cross-sectional view of the stainless steel outer casing of the present invention;

[0054] Figure 4 This is a schematic diagram of a silicon nitride ceramic circular plate according to the present invention;

[0055] Figure 5 This is a schematic diagram of a silicon nitride ceramic sealing plate of the present invention;

[0056] Figure 6 This is a schematic diagram of a structure of the mica ring gasket of the present invention;

[0057] Figure 7 These are SEM images of the welds in Embodiments 1-3 and the comparative examples of the present invention;

[0058] Figure 8 This is a pressure test diagram of Embodiment 1 of the present invention. Detailed Implementation

[0059] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0060] Example 1

[0061] like Figures 1-6 The illustrated embodiment is an electrical connector for use in a high-voltage environment enclosure, comprising a cylindrical stainless steel outer shell 1, a T-shaped stainless steel inner shell 2 extending into the stainless steel outer shell and detachably connected to the upper part of the stainless steel outer shell, a silicon nitride ceramic disc 3, five vertically extending copper core wires 4, and copper core wire sleeves 41 located on the upper part of the copper core wires; both the upper and lower ends of the stainless steel inner shell and the stainless steel outer shell are open, and a stainless steel annular support frame 11 is provided in the middle of the inner side of the stainless steel outer shell, with the silicon nitride ceramic disc located on the stainless steel annular support frame; the silicon nitride ceramic disc has five through holes 30, and an annular groove 31 for accommodating solder is provided above the through holes, with the copper core wires passing downward through the corresponding through holes and brazed to the corresponding through holes; the upper part of the outer side of the silicon nitride ceramic disc has a notch 33 for accommodating solder, and a gap 32 is provided between the inner side of the stainless steel annular support frame and the outer side of the silicon nitride ceramic disc, which are brazed together.

[0062] A mica ring gasket 6 is provided in the middle of the copper core wire, and an annular groove 34 for accommodating the mica ring gasket is provided at the edge of the upper surface of the silicon nitride ceramic disc.

[0063] The lower end of the stainless steel inner shell is provided with a stainless steel annular plate 10, and a stepped hole 101 is provided in the middle of the annular plate. A silicon nitride ceramic sealing plate 5 is provided on the stepped hole. The silicon nitride ceramic sealing plate is provided with 5 sealing holes 50 in the middle. The sealing holes are provided with annular pits 51 for accommodating brazing filler metal. The lower part of the copper core line passes through the corresponding sealing hole and is brazed to the sealing hole. There is a gap between the outer side of the silicon nitride ceramic sealing plate and the upper part of the inner side of the stepped hole. The outer side of the silicon nitride ceramic sealing plate is brazed to the inner side of the stepped hole.

[0064] The solder is composed of Ag, Cu, In metal powder and nano titanium oxide powder, with a mass ratio of Ag, Cu, In metal powder and nano titanium oxide powder of 10:6:3:1.

[0065] The upper part of the inner side of the stainless steel outer shell is provided with an internal thread 12, and the outer side of the stainless steel inner shell is provided with an external thread 21, with the internal thread and the external thread meshing with each other; the lower part of the outer side of the stainless steel outer shell is provided with an installation thread 13.

[0066] A brazing method for electrical connectors used in high-voltage environment enclosures includes the following steps:

[0067] The silicon nitride ceramic disc and the silicon nitride ceramic sealing plate were boiled in distilled water for 10 minutes, dried, and then ultrasonically cleaned and dried with anhydrous ethanol. The stainless steel outer shell and the stainless steel inner shell were ultrasonically cleaned and dried with anhydrous ethanol and then degassed under vacuum at 1050°C.

[0068] Step 1-1, Pre-welding assembly:

[0069] Solder is applied to the upper outer part of the silicon nitride ceramic sealing plate, and solder is applied to the annular pit. The silicon nitride ceramic sealing plate is then placed in the upper part of the stepped hole.

[0070] Solder is applied to the annular groove; solder is applied to the outer surface of the silicon nitride ceramic disc; the silicon nitride ceramic disc is placed on a stainless steel annular support frame, and the copper core wire is inserted into the corresponding through hole and sealing hole in sequence, so that the copper core wire passes through the lower end of the stainless steel lower housing to obtain the assembly.

[0071] Steps 1-2, Vacuuming:

[0072] Place the hollow base at the bottom of the assembly, and then stand the assembly vertically in the vacuum brazing furnace. Use the three-stage pump of the vacuum brazing furnace to evacuate the furnace to a vacuum level of 10. -2 Below Pa;

[0073] Steps 1-3, Pre-welding heating:

[0074] The temperature inside the vacuum brazing furnace is raised from room temperature to T1, where T1 is in the range of 250℃, the heating rate is 6℃ / min, and the holding time is 30min.

[0075] The temperature inside the vacuum brazing furnace is raised from T1 to T2, where T2 is in the range of 600℃, the heating rate is 5℃ / min, and the holding time is 15min.

[0076] The temperature inside the vacuum brazing furnace is raised from T2 to T3, where T3 is 750℃, the heating rate is 5℃ / min, and the holding time is 15min.

[0077] Steps 1-4: Perform brazing.

[0078] Step 1-4-1: Increase the temperature in the vacuum brazing furnace from T3 to T4. The value of T4 is 860℃. The heating rate is 3℃ / min. Hold the temperature for 15min.

[0079] Step 1-4-2: The solder melts and seals the copper core wire to the silicon nitride ceramic disc. The solder seals the outer side of the silicon nitride ceramic disc to the stainless steel annular support frame. The solder seals the outer side of the silicon nitride ceramic sealing plate to the upper part of the inner side of the stepped hole. The solder seals the copper core wire to the silicon nitride ceramic sealing plate.

[0080] Steps 1-5: Release internal stress:

[0081] The temperature inside the vacuum brazing furnace is reduced from T4 to T5, where T5 is 650℃, the cooling rate is 5℃ / min, and the holding time is 80min.

[0082] Steps 1-6: Reduce the temperature inside the vacuum brazing furnace from T5 to room temperature, remove the assembly from the vacuum brazing furnace, and the brazing is complete;

[0083] Place the mica ring gasket onto each copper core wire, allowing it to fall into the annular groove. Then, place a copper core wire sleeve on the upper part of each copper core wire. Insert the stainless steel inner shell into the upper part of the stainless steel outer shell, allowing the mica ring gasket to float along each copper core wire. This allows the copper core wire sleeve to extend beyond the upper end of the stainless steel inner shell, completing the electrical connector assembly.

[0084] When in use, rotate the electrical connector 90° counterclockwise so that the right end of the copper core wire is connected to the sensor in the high-voltage environment box, and the left end of the copper core wire is connected to the signal receiver. The stainless steel housing is then connected to the high-voltage environment box via the mounting threads. The mica ring gasket can float left and right along each copper core wire, effectively dispersing the stress on the silicon nitride ceramic disc.

[0085] Example 2

[0086] In Example 2, the mass ratio of Ag, Cu, In metal powder and nano titanium oxide powder in the solder was 12:5:2:1.

[0087] The other structural and methodological aspects of Example 2 are the same as those in Example 1.

[0088] Example 3

[0089] The mass ratio of Ag, Cu, In metal powder and nano titanium oxide powder in the solder of Example 3 is 14:4:1:1.

[0090] The other structural and methodological aspects of Example 3 are the same as those in Example 1.

[0091] Comparative Example

[0092] The outer surface of a silicon nitride ceramic disc is brazed to a stainless steel annular support frame using AgCuTi active solder, which is held at 880℃ for 10 minutes. The AgCuTi active solder contains 4% Ti and the AgCu alloy is Ag72Cu28.

[0093] Performance testing:

[0094] 1. The electrical connectors of Examples 1-3 and the comparative example were placed on a universal testing machine to test the shear strength of the weld between the outer surface of the silicon nitride ceramic disc and the stainless steel annular support frame. The electrical connectors were placed on a nanoindenter to test the weld between the outer surface of the silicon nitride ceramic disc and the stainless steel annular support frame. The residual stress of the weld was calculated according to the Suresh model. The results are shown in Table 1.

[0095]

[0096]

[0097] Table 1

[0098] It can be seen that the shear strength of the welds in Examples 1-3 is much better than that of the comparative example; when the mass ratio of Ag, Cu, In metal powder and nano titanium oxide powder is 10:6:3:1, the shear strength of the weld is as high as 308.57 MPa and the residual stress value is 0.21 GPa.

[0099] like Figure 7 As shown, the weld seams between the outer surface of the silicon nitride ceramic disc and the stainless steel annular support frame of the electrical connectors in Examples 1, 2, 3, and the comparative example were scanned and inspected. Figure 7 Figures (a)-(d) in the figure correspond to Example 3, Example 2, Example 1 and the comparative example, respectively. It can be seen that the nano-titanium oxide particles are uniformly dispersed in the solder matrix, while in the AgCuTi solder, the Ti element is segregated at the grain boundaries or in some local areas, resulting in non-uniformity of composition and structure.

[0100] Analysis shows that due to the dispersion strengthening and fine grain strengthening effect of nano-titanium oxide particles, the strength of the nano-titanium oxide reinforced AgCuIn solder of the present invention is higher than that of AgCuTi solder. Compared with AgCuTi solder, the nano-titanium oxide reinforced AgCuIn solder is less prone to brittle fracture when subjected to impact or vibration, and can better adapt to complex working environments.

[0101] Meanwhile, nano-titanium oxide has a relatively low coefficient of thermal expansion. When added to AgCuIn solder, it can reduce the overall coefficient of thermal expansion of the solder to a certain extent. In contrast, AgCuTi solder has a relatively high coefficient of thermal expansion. Under thermal cycling conditions, the weld is more prone to thermal stress, which can lead to weld failure.

[0102] 2. For example Figure 8 As shown, a pressure test was performed on the electrical connector of Example 1 after brazing. It can be seen that after the pressure reached 15.8 MPa, the pressure was released and the silicon nitride ceramic disc did not fall off the stainless steel shell, and the airtightness remained intact.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrical connector for use in a high-voltage environment enclosure, characterized in that, The system includes a vertically cylindrical stainless steel outer shell (1), a T-shaped stainless steel inner shell (2) extending into the stainless steel outer shell and detachably connected to the upper part of the stainless steel outer shell, a silicon nitride ceramic disc (3), M vertically extending copper core wires (4), and copper core wire sleeves (41) located on the upper part of the copper core wires, where M ≥ 3; the upper and lower ends of the stainless steel inner shell and the stainless steel outer shell are open, and a stainless steel annular support frame (11) is provided in the middle of the inner side of the stainless steel outer shell, with the silicon nitride ceramic disc located on the stainless steel annular support frame; the silicon nitride ceramic disc is provided with M through holes (30), and an annular groove (31) for accommodating solder is provided above the through holes, with the copper core wires passing downward through the corresponding through holes and brazed to the corresponding through holes; the upper part of the outer side of the silicon nitride ceramic disc is provided with a notch (33) for accommodating solder, and a gap (32) is provided between the inner side of the stainless steel annular support frame and the outer side of the silicon nitride ceramic disc, with the inner side of the stainless steel annular support frame and the outer side of the silicon nitride ceramic disc being brazed together.

2. The electrical connector for use in a high-voltage environment enclosure according to claim 1, characterized in that, The copper core wire is provided with a mica ring gasket (6) in the middle, and the silicon nitride ceramic plate has an annular groove (34) at the upper surface edge for accommodating the mica ring gasket.

3. The electrical connector for use in a high-voltage environment enclosure according to claim 1, characterized in that, The lower end of the stainless steel inner shell is provided with a stainless steel annular plate (10), and a stepped hole (101) is provided in the middle of the annular plate. A silicon nitride ceramic sealing plate (5) is provided on the stepped hole. M sealing holes (50) are provided in the middle of the silicon nitride ceramic sealing plate. An annular pit (51) for accommodating brazing filler metal is provided on the sealing hole. The lower part of the copper core line passes through the corresponding sealing hole and is brazed to the sealing hole. A gap is provided between the outer side of the silicon nitride ceramic sealing plate and the upper part of the inner side of the stepped hole. The outer side of the silicon nitride ceramic sealing plate is brazed to the inner side of the stepped hole.

4. The electrical connector for use in a high-voltage environment enclosure according to claim 1, characterized in that, The solder is composed of Ag, Cu, In metal powder and nano titanium oxide powder, and the mass ratio of Ag, Cu, In metal powder and nano titanium oxide powder in the solder is (10-14):(4-6):(1-3):

1.

5. The electrical connector for use in a high-voltage environment enclosure according to claim 1, characterized in that, The upper part of the inner side of the stainless steel outer shell is provided with an internal thread (12), and the outer side of the stainless steel inner shell is provided with an external thread (21), and the internal thread and the external thread are engaged; the lower part of the outer side of the stainless steel outer shell is provided with an installation thread (13).

6. A brazing method for an electrical connector in a high-voltage environment enclosure according to claim 1, characterized in that, The steps include the following: Step 1-1, Pre-welding assembly: Insert the copper core wire into the corresponding through hole, apply solder to the annular groove, and apply solder to the outer surface of the silicon nitride ceramic disc. A silicon nitride ceramic disc is placed on a stainless steel annular support frame, allowing the copper core wire to pass through the lower end of the stainless steel lower housing, thus obtaining the assembly. Steps 1-2, Vacuuming: Place the hollow base at the bottom of the assembly, and then stand the assembly vertically in the vacuum brazing furnace. Use the three-stage pump of the vacuum brazing furnace to evacuate the furnace to a vacuum level of 10. -2 Below Pa; Steps 1-3, Pre-welding heating: The temperature inside the vacuum brazing furnace is raised from room temperature to T1, where T1 ranges from 240℃ to 250℃, the heating rate is 5℃ / min to 6℃ / min, and the holding time is 25min to 30min. The temperature inside the vacuum brazing furnace is raised from T1 to T2, where T2 ranges from 550℃ to 600℃, the heating rate is 4.5℃ / min to 5℃ / min, and the holding time is 10min to 15min. The temperature inside the vacuum brazing furnace is raised from T2 to T3, with T3 ranging from 700℃ to 750℃, at a heating rate of 4.5℃ / min to 5℃ / min, and held for 10 to 15 minutes. Steps 1-4: Perform brazing. Step 1-4-1: Raise the temperature in the vacuum brazing furnace from T3 to T4. The value of T4 is in the range of 800℃-860℃, the heating rate is 1℃ / min-3℃ / min, and the holding time is 10min-15min. Step 1-4-2: The solder melts and seals the copper core wire to the silicon nitride ceramic disc. The solder also seals the outer side of the silicon nitride ceramic disc to the stainless steel annular support frame. Steps 1-5: Release internal stress: The temperature inside the vacuum brazing furnace is reduced from T4 to T5, where T5 is in the range of 600℃-650℃, the cooling rate is >4℃ / min, and the holding time is 70min-80min. Steps 1-6: Reduce the temperature inside the vacuum brazing furnace from T5 to room temperature, remove the assembly from the vacuum brazing furnace, and the brazing is complete.

7. The brazing method for electrical connectors in a high-voltage environment enclosure according to claim 6, characterized in that, The copper core wire has a mica ring gasket in the middle, and the upper surface edge of the silicon nitride ceramic disc has an annular groove for accommodating the mica ring gasket; the process also includes the following electrical connector assembly process: Place the mica ring gasket onto each copper core wire, allowing it to fall into the annular groove. Then, place a copper core wire sleeve on the upper part of each copper core wire. Insert the stainless steel inner shell into the upper part of the stainless steel outer shell, allowing the mica ring gasket to float along each copper core wire. This allows the copper core wire sleeve to extend beyond the upper end of the stainless steel inner shell, completing the electrical connector assembly.

8. The brazing method for electrical connectors in a high-voltage environment enclosure according to claim 6 or 7, characterized in that, The lower end of the stainless steel inner shell is provided with a ring plate made of stainless steel. The ring plate has a stepped hole in the middle, and a silicon nitride ceramic sealing plate is provided on the stepped hole. The silicon nitride ceramic sealing plate has M sealing holes in the middle. The sealing holes have annular pits for receiving brazing filler metal. The lower part of the copper core line passes through the corresponding sealing hole and is brazed to the sealing hole. There is a gap between the outer side of the silicon nitride ceramic sealing plate and the upper part of the inner side of the stepped hole. The outer side of the silicon nitride ceramic sealing plate is brazed to the inner side of the stepped hole. Step 1-1 is replaced by the following steps: Solder is applied to the upper outer part of the silicon nitride ceramic sealing plate, and solder is applied to the annular pit. The silicon nitride ceramic sealing plate is then placed in the upper part of the stepped hole. Solder is applied to the annular groove; solder is applied to the outer surface of the silicon nitride ceramic disc; the silicon nitride ceramic disc is placed on a stainless steel annular support frame, and the copper core wire is inserted into the corresponding through hole and sealing hole in sequence, so that the copper core wire passes through the lower end of the stainless steel lower housing to obtain the assembly. Step 1-4-2 is replaced by the following steps: The solder melts and seals the copper core wire to the silicon nitride ceramic disc. The solder seals the outer side of the silicon nitride ceramic disc to the stainless steel annular support frame. The solder seals the outer side of the silicon nitride ceramic sealing plate to the upper inner side of the stepped hole. The solder seals the copper core wire to the silicon nitride ceramic sealing plate.

Images