Plating layer with super wear resistance and high electric contact reliability and processing technology

Abstract

The invention relates to the technical field of electronic components, discloses a plating layer with super wear resistance and high electric contact reliability and a processing technology, and solves the problems that an existing plating layer is poor in wear resistance, easy to wear through and unstable in electric contact performance. Through the arrangement of the hard bottom plating layer, the hard precious metal layer, the soft pure gold lubricating layer and the organic lubricant layer of the terminal base material, by adopting the technological process provided by the embodiment, the wear resistance and the electric contact reliability of the plating layer are improved, in addition, the motor is used for driving the rotating shaft to rotate, and the rotating shaft is used for driving the short shaft and the inner disc to rotate, so that the service life of the terminal base material is prolonged. Therefore, the rotation of the workpiece in the vacuum sputtering process is realized, and the consistency of a plating layer is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, in particular to a plating layer and a processing technology with super wear resistance and high electrical contact reliability. Background Art

[0002] Common metal parts used for electrical connections on the market are usually copper alloy or stainless steel terminals with nickel and hard gold plating on the surface. Nickel acts as a base plating to isolate and support, preventing the mutual penetration between the precious metal and the base metal and corrosion by the environmental medium, while avoiding rapid wear and tear during mechanical friction, which may lead to electrical connection failure. However, when used for frequent plugging and unplugging connectors or high-speed switches, the nickel layer is insufficient in strength, or the precious metal plating does not have self-lubricating properties, which can easily lead to wear and failure. As a result, abnormal electrical performance remains a major contradiction plaguing the industry.

[0003] The existing Chinese patent application number CN201911247003.4 discloses a NdFeB composite coating, comprising a NdFeB substrate layer, at least one water-plated layer located on the upper surface of the NdFeB substrate layer, and at least one PVD vacuum-plated layer located on the upper surface of the water-plated layer. The NdFeB composite coating utilizes the synergistic effect of the water-plated layer and the PVD vacuum-plated layer to stagger the pores in the two different coatings, reduce the porosity, increase the density of the NdFeB composite coating, and have a higher hardness, thereby improving the NdFeB composite coating. The wear resistance and corrosion resistance of the layer are improved. The salt spray test of the NdFeB composite coating can reach more than 144 hours, and the hardness exceeds 3000HV, which improves the reliability and durability of the adapter. However, in daily use, the surface coating is worn through after less than 5,000 friction switches, and the service life is short. Since the coating does not have a self-lubricating effect, it is prone to abnormal running-in in the early stage. In addition, the surface is not covered with precious metals, the impedance is high, and it is not suitable for the field of electronic connectors mainly for signal transmission.

[0004] In view of the above problems, a plating layer and a processing technology with super wear resistance and high electrical contact reliability are proposed to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a coating and processing technology with super wear resistance and high electrical contact reliability. The device is used to solve the problem of poor wear resistance of existing coatings, which leads to electrical performance degradation.

[0006] To achieve the above object, the present invention provides the following technical solutions: A coating with super wear resistance and high electrical contact reliability, the coating having a composite structure, the coating composite structure including a hard bottom coating provided on the upper surface of the terminal substrate, a hard precious metal layer provided on the upper surface of the hard bottom coating, a soft pure gold lubricating layer provided on the upper surface of the hard precious metal layer, and an organic lubricant layer provided on the upper surface of the soft pure gold lubricating layer; Further, the hard bottom coating is one or more of titanium, tungsten, chromium, titanium tungsten, titanium chromium, nickel chromium, nickel tungsten, and tungsten chromium deposited by physical vapor deposition.

[0007] Further, the hard bottom coating is one or more of crystalline nickel tungsten, crystalline nickel chromium, and crystalline nickel tungsten chromium deposited by aqueous solution electroplating.

[0008] Further, the hard precious metal layer is made of one or more of platinum, rhodium, iridium, nickel-containing hard gold, and cobalt-containing hard gold, wherein the mass ratio of nickel in the nickel-containing hard gold is 0.1-5%, the mass ratio of cobalt in the cobalt-containing hard gold is 0.1-5%, and the thickness range of the hard precious metal layer is 0.2-6 μm; Further, the soft pure gold lubricating layer is made of soft pure gold, and the thickness range of the soft pure gold lubricating layer is 0.1-1 μm; The organic lubricant layer is selected from an organic oil film or a surfactant organic adsorption film, and the thickness range of the organic lubricant layer is 0.1-5 μm.

[0009] Further, a processing process for a coating includes the following steps: S1: Immerse the workpiece in a solution containing a degreasing agent, and decompose the grease through the saponification reaction of the degreasing agent with the grease. During the degreasing process, the temperature range is 50-70°C, the current range is 0.5-5 A / dm 2 , and the time range is 1-5 min to achieve preliminary cleaning of the workpiece; S2: Take out the degreased workpiece and use a multi-stage rinsing method, with each rinsing time being 1-3 min to ensure that the degreasing agent and impurities on the surface of the workpiece are fully removed; S3: Apply the coating; S4: Then perform electroplating of hard gold: Select one or several of platinum, rhodium, iridium, nickel-containing hard gold, or cobalt-containing hard gold, immerse the workpiece in the electroplating solution, with a temperature of 55-65°C and a current of 0.1-30 A / dm 2 , a time of 10 s-60 min, and a pH of 4.0-4.6; S5: Electroplate platinum, rhodium, and iridium in sequence; S6: Then perform electroplating of soft gold: Immerse the workpiece in the electroplating solution, with a temperature of 55-65°C and a current of 0.1-10 A / dm 2 , a time of 5 s-6 min, and a pH of 4.0-5.0; S7: Coating a liquid organic film: For the oily film, mineral oil is used and formulated with a diluent to a mass concentration of 0.1 - 1%. For the water-soluble surfactant adsorption film, thiazole derivatives, azole derivatives, and alkyl mercaptans are used, with a concentration of 1 - 10%. The temperature range is 30 - 60 °C, and the time range is 5 s - 3 min.

[0010] Further, the plating process in S3 is a PVD sputtering process. The dried workpiece is placed in a vacuum chamber. The hydrogen partial pressure is controlled in the range of 0.1 - 0.5 MPa, the power is in the range of 100 - 500 W, and the time is in the range of 2 - 5 min to perform plasma cleaning on the workpiece. The workpiece after plasma cleaning enters a vacuum sputtering device. The working air pressure is controlled in the range of 0.1 - 0.9 Pa, argon is used as the sputtering gas, and the sputtering current is in the range of 0.5 - 2 A / dm 2 , the voltage range is 120 - 200 V. For single metals, single-target sputtering is used, and for alloys, alloy single-target sputtering or dual-target hybrid sputtering is used.

[0011] Further, the specific implementation steps of the vacuum sputtering device are as follows: S301: Before the sputtering operation, use a vacuum pump to evacuate the vacuum tank. When the predetermined air pressure is reached, while keeping the vacuum pump on, use an air pump to introduce the argon gas stored in the gas storage tank into the vacuum tank. S302: When the air pressure in the vacuum tank reaches the predetermined range, energize the target using the power supply base, ionize the argon gas through a high-voltage electric field to form a plasma, and start the sputtering operation. S303: During the sputtering process, use a motor to drive the rotation of the rotating shaft. The rotating shaft drives the short shaft and the inner disk to rotate, thereby driving the turntable to rotate inside the chassis. Under the clamping action of the clamping plate on the workpiece, the workpiece makes a circular motion during the vacuum sputtering process until the vacuum spraying work is completed.

[0012] Further, the clamping of the workpiece by the clamping plate in S303 is specifically as follows: First, insert the bottom end of the workpiece into the clamping groove on the upper surface of the chassis. After the workpiece is placed inside the clamping groove, the pressing plate is driven to press down by the gravity of the workpiece itself and the pressure above, while compressing the spring rod A and driving the pressing plate to flip. Use the clamping plate to clamp both sides of the workpiece. This clamping method can further press down the spring rod A when vibration occurs during the spraying process, so that the clamping plate clamps more tightly. The spring rod A and the torsion spring are used for the subsequent reset of the spring rod A and the short rod. Then, manually press the movable plate to compress the spring rod B, and then press down the fixing frame so that the fixing block on the bottom surface of the docking plate corresponds to the top end of the workpiece. After clamping the top end of the workpiece, release the movable plate, and insert the positioning plate into the positioning card slot for positioning and fixing.

[0013] Furthermore, the plating process of S3 is an electroplating process. For the acid activation pretreatment of the nickel-tungsten, nickel-chromium, and nickel-tungsten-chromium hard alloy bottom plating, use a sulfuric acid solution with a mass ratio of 5-30%, soak for 10s-3min, then immerse the workpiece in the electroplating solution at a temperature of 55-70°C, use a direct current of 0.5-5A / dm 2 , for 2-30min, and the pH is 3.0-4.5.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: A plating layer and processing technology with ultra-high wear resistance and high electrical contact reliability proposed by the present invention, through the settings of the terminal substrate, bottom plating layer, hard precious metal layer, soft pure gold lubricating layer, and organic lubricant layer, and adopting the process flow provided in this embodiment, thereby improving the wear resistance and electrical contact reliability of the plating layer. In addition, by using the motor to drive the rotation of the rotating shaft, and using the rotating shaft to drive the rotation of the short shaft and the inner disk, thereby driving the rotation of the turntable inside the chassis, and then realizing the rotation of the workpiece during the vacuum sputtering process, ensuring the spraying uniformity, and finally achieving the effect of ensuring the spraying uniformity. Description of the Drawings

[0015] Figure 1 Schematically shows the hierarchical structure diagram of the plating layer structure proposed according to an embodiment of the present invention; Figure 2 Schematically shows the overall structure diagram A proposed according to an embodiment of the present invention; Figure 3 Schematically shows the overall structure diagram B proposed according to an embodiment of the present invention; Figure 4 Schematically shows the internal structure diagram of the vacuum tank proposed according to an embodiment of the present invention; Figure 5 Schematically shows the structure diagram of the power supply seat and the chassis proposed according to an embodiment of the present invention; Figure 6 Schematically shows the structure diagram of the chassis proposed according to an embodiment of the present invention; Figure 7 Schematically shows the structure diagram of the rotating assembly proposed according to an embodiment of the present invention; Figure 8 Schematically shows the structure diagram of the turntable proposed according to an embodiment of the present invention; Figure 9 Schematically shows the structure diagram of the fixing block proposed according to an embodiment of the present invention; Figure 10 Schematically shows the structure diagram of the fixing component proposed according to an embodiment of the present invention; Figure 11Schematically shows a schematic structural diagram of a positioning component proposed according to an embodiment of the present invention; Figure 12 Schematically shows a schematic working principle diagram of the vacuum sputtering method proposed according to an embodiment of the present invention; Figure 13 Schematically shows a schematic working principle diagram of the electroplating method proposed according to an embodiment of the present invention.

[0016] In the figure: 1, vacuum tank; 11, pipe cover; 111, side connection plate; 112, bolt A; 12, sealing ring; 13, vacuum pump; 131, exhaust pipe; 14, side frame; 15, rod frame; 151, positioning card slot; 152, chassis; 153, turntable; 154, limit ring; 16, support platform; 161, motor; 162, rotating shaft; 17, controller; 2, workpiece; 21, organic lubricant layer; 22, soft pure gold lubricating layer; 23, hard precious metal layer; 24, hard bottom plating layer; 25, terminal substrate; 3, gas storage tank; 31, air pump; 32, gas transmission pipe; 4, fixing component; 41, fixing frame; 42, handle; 43, positioning slot; 44, positioning component; 441, spring rod B; 442, movable plate; 443, positioning plate; 5, rotating component; 51, short shaft; 52, inner disc; 53, spring A; 54, chuck; 55, convex block; 6, power supply base; 61, sleeve frame; 62, target body; 7, fixing block; 71, clamping groove; 72, spring rod A; 73, resisting plate; 74, short rod; 75, torsion spring; 76, pressing plate; 77, clamping plate. Specific embodiments

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] To further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings. Embodiment

[0019] Combined with Figures 1-13 , a plating layer with ultra-high wear resistance and high electrical contact reliability, the plating layer has a composite structure, and the composite structure of the plating layer includes a hard bottom plating layer 24 provided on the upper surface of the terminal substrate 25, a hard precious metal layer 23 provided on the upper surface of the hard bottom plating layer 24, a soft pure gold lubricating layer 22 provided on the upper surface of the hard precious metal layer 23, and an organic lubricant layer 21 provided on the upper surface of the soft pure gold lubricating layer 22; The hard bottom coating 24 is one or more of physically vapor-deposited titanium, tungsten, chromium, titanium tungsten, titanium chromium, nickel chromium, nickel tungsten, and tungsten chromium; The hard bottom coating 24 is one or more of crystalline nickel tungsten, crystalline nickel chromium, and crystalline nickel tungsten chromium deposited by aqueous solution electroplating; The hard noble metal layer 23 is made of one or more of platinum, rhodium, iridium, nickel-containing hard gold, and cobalt-containing hard gold, wherein the nickel mass fraction in the nickel-containing hard gold is 0.1 - 5%, the cobalt mass fraction in the cobalt-containing hard gold is 0.1 - 5%, and the thickness range of the hard noble metal layer 23 is 0.2 - 6 μm; The soft pure gold lubricating layer 22 is made of soft pure gold, and the thickness range of the soft pure gold lubricating layer 22 is 0.1 - 1 μm; The organic lubricant layer 21 is selected from an organic oil film or a surfactant organic adsorption film, and the thickness range of the organic lubricant layer 21 is 0.1 - 5 μm.

[0020] The present invention will be further described below in conjunction with embodiments.

[0021] A processing technology for a coating with ultra-high wear resistance and high electrical contact reliability includes the following steps: S1: Immerse the workpiece in a solution containing a degreasing agent, and decompose the grease through the saponification reaction between the degreasing agent and the grease. During the degreasing process, the temperature range is 50 - 70 °C, the current range is 0.5 - 5 A / dm 2 , and the time range is 1 - 5 min to achieve preliminary cleaning of the workpiece; S2: Take out the degreased workpiece and use a multi-stage rinsing method, with each rinsing time being 1 - 3 min to ensure that the degreasing agent and impurities on the workpiece surface are fully removed; S3: Put the rinsed workpiece into a drying oven, and evaporate the moisture on the workpiece surface through hot air circulation. The drying temperature range is 80 - 120 °C, and the drying time range is 10 - 30 min; S4: Select PVD sputtering to make the hard bottom coating. Corresponding plasma pretreatment: Put the dried workpiece into a vacuum chamber, control the hydrogen partial pressure range to be 0.1 - 0.5 MPa, the power range to be 100 - 500 W, and the time range to be 2 - 5 min to perform plasma cleaning on the workpiece to ensure the cleanliness of the workpiece surface; S5: Select PVD sputtering to make the hard bottom coating: The workpiece after plasma cleaning enters a vacuum sputtering device, control the working gas pressure range to be 0.1 - 0.9 Pa, use argon as the sputtering gas, and the sputtering current range is 0.5 - 2 A / dm 2 , the voltage range is 120 - 200 V. For single metals, single-target sputtering is used, and for alloys, alloy single-target sputtering or dual-target hybrid sputtering is used; S51: Before sputtering, use the vacuum pump 13 to evacuate the vacuum chamber 1. When the predetermined air pressure is reached, while keeping the vacuum pump 13 on, use the air pump 31 to introduce the argon gas stored in the gas storage tank 3 into the vacuum chamber 1; S52: After the air pressure in the vacuum chamber 1 reaches the predetermined range, energize the target using the power supply base 6, ionize the argon gas through the high-voltage electric field to form a plasma, and start the sputtering operation; S53: During sputtering, use the motor 161 to drive the rotation of the rotating shaft 162. The rotating shaft 162 drives the short shaft 51 and the inner disk 52 to rotate, thereby driving the turntable 153 to rotate inside the chassis 152. Under the clamping action of the clamping plate 77 on the workpiece, the workpiece 2 makes a circular motion during the vacuum sputtering process until the vacuum spraying operation is completed.

[0022] In S5, the vacuum sputtering device includes a vacuum chamber 1. A pipe cover 11 is provided on the upper surface of the vacuum chamber 1. A vacuum pump 13 is fixedly connected to the outside of the vacuum chamber 1. An exhaust pipe 131 is fixedly connected to the outside of the vacuum pump 13. A gas storage tank 3 is provided on one side of the vacuum chamber 1. An air pump 31 is provided on the outside of the gas storage tank 3. A gas delivery pipe 32 is fixedly connected to one side of the air pump 31. The gas delivery pipe 32 is communicated with the inside of the vacuum chamber 1. A power supply base 6 is provided inside the vacuum chamber 1. A sleeve 61 is fixedly connected to the upper surface of the power supply base 6. A target body 62 is clamped inside the sleeve 61. During sputtering, use the vacuum pump 13 to evacuate the vacuum chamber 1. When the predetermined air pressure is reached, turn on the air pump 31, introduce the argon gas stored inside the gas storage tank 3 into the vacuum chamber 1 through the gas delivery pipe 32, and at the same time use the power supply base 6 to energize the target, ionize the argon gas through the high-voltage electric field to form a plasma, providing an ion source for sputtering. With the continuous introduction of argon gas into the electric field environment and the cooperation of the target, the vacuum sputtering operation of the workpiece 2 is realized.

[0023] A side frame 14 is fixedly connected to the inner wall of the vacuum chamber 1. A rod frame 15 is clamped inside the side frame 14. A chassis 152 is fixedly connected to the bottom surface of the rod frame 15. A support platform 16 is fixedly connected to the bottom surface of the inner wall of the vacuum chamber 1. A motor 161 is arranged inside the support platform 16. The output end of the motor 161 is fixedly connected to a rotating shaft 162. One end of the rotating shaft 162 is provided with a rotating assembly 5. The rotating assembly 5 includes a short shaft 51 fixedly connected to one end of the rotating shaft 162. The upper end of the short shaft 51 is fixedly connected to an inner disk 52. A turntable 153 is rotatably connected inside the chassis 152. A limiting ring 154 is fixedly connected to the outer side of the turntable 153. The limiting ring 154 is rotatably connected to the inner wall of the chassis 152. An installation groove corresponding to the inner disk 52 is formed on the bottom surface of the turntable 153. Before vacuum sputtering, the rod frame 15 with the workpiece 2 installed is clamped inside the side frame 14. During the vacuum sputtering process, the motor 161 is turned on. The motor 161 drives the rotating shaft 162 to rotate. The rotating shaft 162 drives the short shaft 51 and the inner disk 52 to rotate, so as to drive the turntable 153 to rotate inside the chassis 152, and then realize the rotation of the workpiece 2 during the vacuum sputtering process. The rotation enables the surface of the workpiece 2 to be continuously exposed to the plasma. The sputtered particles from the target material are cosine-distributed. The rotation of the workpiece 2 makes the probability of each area being bombarded by the particles equal, avoiding local over-thickness or over-thinness.

[0024] Compression grooves are formed on the upper surface of the inner disk 52. A spring A 53 is fixedly connected to the inner wall of the compression groove. The upper surface of the spring A 53 is fixedly connected to a chuck 54. The chuck 54 is slidably connected inside the compression groove. A convex block 55 is fixedly connected to the upper surface of the chuck 54. Grooves corresponding to the convex block 55 are formed on the inner wall of the installation groove. When installing the chassis 152, the convex block 55 is inserted into the groove, so as to ensure the stability of the connection between the inner disk 52 and the chassis 152.

[0025] A fixing block 7 is fixedly connected to the upper surface of the chassis 152. A clamping groove 71 is formed on the upper surface of the fixing block 7. A short rod 74 is rotatably connected to the inner wall of the clamping groove 71. A pressing plate 76 is fixedly connected to the outer side of the short rod 74. A clamping plate 77 is fixedly connected to one side of the pressing plate 76. A spring rod A 72 is fixedly connected to the bottom surface of the inner wall of the clamping groove 71. The upper surface of the spring rod A 72 is fixedly connected to a resisting plate 73. The resisting plate 73 is arranged corresponding to the short rod 74. A torsion spring 75 is arranged at the connection between the short rod 74 and the inner wall of the spring rod A 72. After the workpiece 2 is placed inside the clamping groove 71, the resisting plate 73 is pressed down by the gravity of the workpiece 2 itself and the pressure above. While compressing the spring rod A 72, the pressing plate 76 is driven to flip, and the clamping plate 77 clamps both sides of the workpiece 2. When vibration occurs during the spraying process, the spring rod A 72 can be further pressed down, so that the clamping plate 77 clamps more tightly. The spring rod A 72 and the torsion spring 75 are used for the subsequent reset of the spring rod A 72 and the short rod 74.

[0026] A fixing component 4 is arranged on the outer side of the rod holder 15. The fixing component 4 includes a fixing frame 41 slidably connected to the outer side of the rod holder 15. A grip 42 is fixedly connected to the upper surface of the fixing frame 41. A positioning groove 43 is formed in the upper surface of the fixing frame 41. A positioning component 44 is arranged inside the positioning groove 43. A positioning clamping groove 151 is arranged on one side of the rod holder 15 close to the positioning component 44. The positioning component 44 includes a spring rod B441 fixedly connected to the inner wall of the positioning groove 43. One end of the spring rod B441 is fixedly connected with a movable plate 442. One end of the movable plate 442 is fixedly connected with a positioning plate 443. The positioning plate 443 is arranged corresponding to the positioning clamping groove 151. A docking disc is rotatably connected to the bottom surface of the fixing frame 41. A fixing block 7 having the same structure as the upper surface of the chassis 152 is fixedly connected to the bottom surface of the docking disc. When installing the workpiece 2, first insert the bottom end of the workpiece 2 into the clamping groove 71 on the upper surface of the chassis 152. Then manually press the movable plate 442 to compress the spring rod B441. Then press down the fixing frame 41 to make the fixing block 7 on the bottom surface of the docking disc correspond to the top end of the workpiece 2. After clamping the top end of the workpiece 2 through the clamping plate 77, release the movable plate 442, and insert the positioning plate 443 into the positioning clamping groove 151 to achieve positioning and fixing.

[0027] A sealing ring 12 is fixedly connected to the outer side of the vacuum tank 1. Side connecting plates 111 are fixedly connected to the outer sides of the pipe cover 11 and the sealing ring 12. Two groups of side connecting plates 111 are threadedly connected with bolts A112. A controller 17 for controlling the sputtering device is arranged on the outer side of the vacuum tank 1. The sealing ring 12 is used in cooperation with the pipe cover 11, and the fixing effect is enhanced under the connection action of the side connecting plates 111 and the bolts A112.

[0028] Specifically, when installing the workpiece 2, first insert the bottom end of the workpiece 2 into the clamping groove 71 on the upper surface of the chassis 152. After the workpiece 2 is placed inside the clamping groove 71, the pressing plate 73 is driven to press down by the gravity of the workpiece 2 itself and the pressure above, while compressing the spring rod A72 and driving the pressing plate 76 to flip, and the clamping plate 77 is used to clamp both sides of the workpiece 2. This clamping method can further press down the spring rod A72 when vibration occurs during the spraying process, so that the clamping plate 77 clamps more tightly. The spring rod A72 and the torsion spring 75 are used for the subsequent reset of the spring rod A72 and the short rod 74. Then manually press the movable plate 442 to compress the spring rod B441. Then press down the fixing frame 41 to make the fixing block 7 on the bottom surface of the docking disc correspond to the top end of the workpiece 2. After clamping the top end of the workpiece 2, release the movable plate 442, and insert the positioning plate 443 into the positioning clamping groove 151 to achieve positioning and fixing; Before the sputtering process, the vacuum pump 13 is used to evacuate the vacuum chamber 1. When the predetermined air pressure is reached, the argon gas stored inside the gas storage tank 3 is introduced into the vacuum chamber 1 through the gas delivery pipe 32 by the air pump 31. At the same time, the target is energized by the power supply base 6, and the argon gas is ionized by the high-voltage electric field to form plasma. The motor 161 drives the rotating shaft 162 to rotate, and the rotating shaft 162 drives the short shaft 51 and the inner disk 52 to rotate, thereby driving the turntable 153 to rotate inside the chassis 152, and further realizing the rotation of the workpiece 2 during the vacuum sputtering process to ensure the spraying uniformity. During the sputtering process, the sealing ring 12 is used in cooperation with the pipe cover 11, and the connection effect of the side connecting plate 111 and the bolt A112 is used to enhance the fixing and sealing effect. Rotation makes the surface of the workpiece 2 continuously exposed to the plasma. The particles sputtered from the target show a cosine distribution. The rotation of the workpiece 2 makes the probability of each area being bombarded by the particles equal, avoiding local over-thickness or over-thinness.

[0029] The electroplating of the noble metal layer still adopts the more cost-effective solution electroplating method, including coating the liquid organic lubricating layer and the same as in Example 2 below. Example

[0030] This example provides another processing technology for a coating with super wear resistance and high electrical contact reliability, including the following steps: S1: Immerse the workpiece in a solution containing a degreasing agent. The degreasing agent reacts with the grease to saponify and decompose the grease. During the degreasing process, the temperature range is 50 - 70 °C, the current range is 0.5 - 5 A / dm 2 , and the time range is 1 - 5 min to achieve the preliminary cleaning of the workpiece; S2: Take out the degreased workpiece and adopt a multi-stage rinsing method, with each rinsing time being 1 - 3 min to ensure that the degreasing agent and impurities on the surface of the workpiece are fully removed; S3: Select the acid activation pretreatment for electroplating nickel-tungsten, nickel-chromium, nickel-tungsten-chromium hard alloy bottom coatings in aqueous solution: 5 - 30% sulfuric acid solution by mass ratio, soaking time 10 s - 3 min; S4: Select the electroplating of crystalline nickel-tungsten, nickel-chromium, nickel-tungsten-chromium hard alloy bottom coatings in aqueous solution. Taking nickel-tungsten as an example: Immerse the workpiece in the electroplating solution. The preparation method of the electroplating solution is nickel sulfate [NiSO4∙7H2O] 100 - 360 g / L, nickel chloride [NiCl2∙7H2O] 10 - 50 g / L, potassium citrate 40 - 70 g / L, citric acid 20 - 50 g / L, sodium tungstate [Na2WO4·2H2O] 20 - 160 g / L, temperature 55 - 70 °C, using direct current 0.5 - 5 A / dm 2 , time 2 min - 30 min, pH 3.0 - 4.5, pure nickel anode or insoluble platinum, ruthenium-iridium anode, and adjust the tungsten content in the coating to 5 - 20% by elemental analysis to avoid forming a brittle amorphous coating; S5: Electroplating hard gold: Select one or more of platinum, rhodium, iridium, nickel-containing hard gold, or cobalt-containing hard gold. Immerse the workpiece in the electroplating solution. The preparation method of the plating solution is potassium citrate [C6H5K3O7] 100 - 300 g / L, citric acid [C6H8O7] 50 - 200 g / L, potassium aurocyanide [KAu(CN)2] 3 - 20 g / L, nickel sulfate [NiSO4∙7H2O] or cobalt sulfate [CoSO4] 0.5 - 5 g / L, temperature 55 - 65 °C, current 0.1 - 30 A / dm 2 , time 10 s - 60 min, pH 4.0 - 4.6, insoluble platinum, ruthenium-iridium anode; S6: Electroplating platinum, rhodium, iridium. Taking platinum as an example: Immerse the workpiece in the electroplating solution. The preparation method of the plating solution is platinum sulfate [Pt(SO4)2] 0.5 - 15 g / L or chloroplatinic acid [H2PtCl6] 1 - 20 g / L, sulfuric acid 80 - 200 g / L, temperature 20 - 60 °C, current 0.5 - 5 A / dm 2 , time 5 - 20 min, insoluble platinum, ruthenium-iridium anode; S7: Electroplating soft gold: Immerse the workpiece in the electroplating solution. The preparation method of the plating solution is potassium citrate [C6H5K3O7] 100 - 300 g / L, citric acid [C6H8O7] 50 - 200 g / L, potassium aurocyanide [KAu(CN)2] 10 g / L, thallium sulfate [Tl2SO4] 5 - 20 mg / L, temperature 55 - 70 °C, current 0.1 - 10 A / dm 2 , time 5 s - 6 min, pH 4.0 - 5.0, insoluble platinum, ruthenium-iridium anode; S8: Coating a liquid-phase organic film: For the oily film, use mineral oil and prepare it into a mass concentration of 0.1 - 1% with a diluent. For the water-soluble surfactant adsorption film, use thiazole derivatives, azole derivatives, or alkyl mercaptans, with a concentration of 1 - 10%, temperature range of 30 - 60 °C, and time range of 5 s - 3 min.

[0031] Nickel-tungsten alloy, nickel-chromium alloy, and nickel-tungsten-chromium alloy achieved by an aqueous solution electroplating process, with a thickness specification of 0.5 - 6 μm. The specific process: degreasing - rinsing - acid activation - electroplating nickel alloy using the electroplating solution of the corresponding metal. The electroplating solution is formulated according to the coating characteristics and alloy component requirements, and the components of the electroplating solution need to be analyzed and adjusted periodically, with a frequency usually of 3 - 5 A∙h / L. Compared with vacuum sputtering, electroplating can generate a uniform coating on the surface of workpieces with complex shapes. Relying on the electric field effect, metal ions are evenly deposited, and good coverage can also be achieved in deep holes, grooves, etc. However, in vacuum sputtering, due to the particle movement trajectory, sputtering shadow areas are easily generated, resulting in uneven coating thickness. Through appropriate pretreatment and processes, a strong metallurgical or chemical bonding is formed between the coating and the substrate during electroplating, with strong bonding force and the ability to withstand large mechanical stresses. In this regard, vacuum sputtering is slightly inferior. Electroplating performs well in controlling the coating thickness and can easily achieve the deposition of relatively thick coatings from a few micrometers to dozens of micrometers. Just adjust the parameters according to the requirements. Vacuum sputtering is more suitable for preparing thin coatings below the micron level, and problems such as loose coatings and large internal stresses are likely to occur when thickening. In terms of cost, electroplating equipment is simple, and the operation and material consumption costs are low, suitable for large-scale production. Vacuum sputtering equipment is expensive and has high operating costs. In addition, electroplating has good adaptability to materials. After special pretreatment, both metal and non-metal materials can be electroplated. Although vacuum sputtering can also process a variety of materials, the pretreatment and sputtering conditions are more demanding for special materials and workpieces with special shapes.

[0032] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0033] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coating with ultra-high wear resistance and high electrical contact reliability, characterized in that: The coating has a composite structure. The coating composite structure includes a hard bottom coating disposed on the upper surface of the terminal substrate. A hard precious metal layer is provided on the upper surface of the hard bottom coating. A soft pure gold lubricating layer is provided on the upper surface of the hard precious metal layer. An organic lubricant layer is provided on the upper surface of the soft pure gold lubricating layer.

2. The coating with ultra-high wear resistance and high electrical contact reliability according to claim 1, characterized in that: The hard bottom coating is one or more of titanium, tungsten, chromium, titanium tungsten, titanium chromium, nickel chromium, nickel tungsten, and tungsten chromium deposited by physical vapor deposition.

3. The coating with ultra-high wear resistance and high electrical contact reliability according to claim 1, wherein: The hard bottom coating is one or more of crystalline nickel tungsten, crystalline nickel chromium, and crystalline nickel tungsten chromium deposited by aqueous solution electroplating.

4. The coating with ultra-high wear resistance and high electrical contact reliability according to claim 1, characterized in that: The hard precious metal layer is made of one or more of platinum, rhodium, iridium, nickel-containing hard gold, and cobalt-containing hard gold. The mass ratio of nickel in the nickel-containing hard gold is 0.1-5%, and the mass ratio of cobalt in the cobalt-containing hard gold is 0.1-5%. The thickness range of the hard precious metal layer is 0.2-6 μm.

5. The coating with ultra-high wear resistance and high electrical contact reliability according to claim 1, wherein: The soft pure gold lubricating layer is made of soft pure gold, and the thickness range of the soft pure gold lubricating layer is 0.1-1 μm; The organic lubricant layer is selected from an organic oil film or a surfactant organic adsorption film, and the thickness range of the organic lubricant layer is 0.1-5 μm.

6. A processing technology for a coating, which is used to prepare the coating with ultra - wear resistance and high electrical contact reliability as described in any one of claims 1 - 5, characterized in that: It includes the following steps: S1: Immerse the workpiece in a solution containing a degreasing agent. The degreasing agent reacts with the grease through saponification to decompose the grease. During the degreasing process, the temperature range is 50 - 70 °C, the current range is 0.5 - 5 A / dm 2 , and the time range is 1 - 5 min to achieve preliminary cleaning of the workpiece; S2: Take out the degreased workpiece and use a multi-stage rinsing method with a rinsing time of 1-3 minutes each time to ensure that the degreasing agent and impurities on the surface of the workpiece are fully removed; S3: Perform coating; S4: Then electroplate with hard gold: Select one or more of platinum, rhodium, iridium, nickel-containing hard gold or cobalt-containing hard gold, immerse the workpiece in the electroplating solution at a temperature of 55-65°C, a current of 0.1-30 A / dm 2 , for a time of 10 s - 60 min, and a pH of 4.0 - 4.6; S5: Electroplate platinum, rhodium, and iridium in sequence; S6: Then electroplate soft gold: Immerse the workpiece in the electroplating solution at a temperature of 55 - 65°C, with a current of 0.1 - 10 A / dm 2 , for a time of 5 s - 6 min, and a pH of 4.0 - 5.0; S7: Coat a liquid-phase organic film: The oil film uses mineral oil and is formulated with a diluent to a mass concentration of 0.1-1%. The water-soluble surfactant adsorption film uses thiazole derivatives, azole derivatives, and alkyl mercaptans with a concentration of 1-10%. The temperature range is 30-60 °C, and the time range is 5 s-3 minutes.

7. The processing method of the coating according to claim 6, characterized in that: The coating process of S3 is a PVD sputtering process. Put the dried workpiece into the vacuum chamber, control the hydrogen partial pressure range to be 0.1-0.5 MPa, the power range to be 100-500 W, and the time range to be 2-5 minutes to perform plasma cleaning on the workpiece; The workpiece after plasma cleaning enters the vacuum sputtering device. The working air pressure is controlled in the range of 0.1 - 0.9 Pa, argon is used as the sputtering gas, and the sputtering current range is 0.5 - 2 A / dm 2 , the voltage range is 120 - 200 V. For single metals, single-target sputtering is used, and for alloys, alloy single-target sputtering or dual-target hybrid sputtering is adopted.

8. The processing technology of the coating according to claim 7, characterized in that: The specific implementation steps of the vacuum sputtering device are as follows: S301: Before sputtering work, use a vacuum pump to evacuate the vacuum tank. When the predetermined air pressure is reached, while keeping the vacuum pump on, use an air pump to introduce argon gas stored in the gas storage tank into the vacuum tank; S302: When the air pressure in the vacuum tank reaches the predetermined range, energize the target material through the power supply base, ionize argon gas through a high-voltage electric field to form a plasma, and start sputtering work; S303: During sputtering, use a motor to drive the rotation of the rotating shaft. The rotating shaft drives the short shaft and the inner disk to rotate, thereby driving the turntable to rotate inside the chassis. Under the clamping action of the clamping plate on the workpiece, the workpiece makes a circular motion during vacuum sputtering until the vacuum spraying work is completed.

9. The processing technology of the coating according to claim 8, characterized in that: The clamping of the workpiece by the clamping plate in S303 is specifically as follows: First, insert the bottom end of the workpiece into the clamping groove on the upper surface of the chassis. After the workpiece is placed inside the clamping groove, the pressing plate is driven to press down by the gravity of the workpiece itself and the pressure above, while compressing the spring rod A, and at the same time driving the pressing plate to flip, and the clamping plate is used to clamp both sides of the workpiece. The spring rod A and the torsion spring are used for the subsequent reset of the spring rod A and the short rod. Subsequently, manually press the movable plate to compress the spring rod B, and then press down the fixing frame to make the fixing block on the bottom surface of the docking plate correspond to the top end of the workpiece. After the clamping of the top end of the workpiece is completed, release the movable plate, and the positioning is fixed by inserting the positioning plate into the positioning card slot.

10. The processing technology of the coating according to claim 6, characterized in that: The plating process of S3 is an electroplating process. For the acid activation pretreatment of the nickel-tungsten, nickel-chromium, and nickel-tungsten-chromium hard alloy bottom coatings, use a sulfuric acid solution with a mass ratio of 5-30%, soak for 10s-3min, then immerse the workpiece in the electroplating solution at a temperature of 55-70°C, use a direct current of 0.5-5A / dm 2 , for 2-30min, with a pH of 3.0-4.5.

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