A method of electroplating a plug shield

Abstract

The application relates to the technical field of electroplating, and discloses an electroplating method for a plug shielding member, which comprises the following steps: performing surface pretreatment on the plug shielding member; placing the plug shielding member in an electrolyte for electroplating; in the electroplating process, an electric field distribution is regulated through a main electrode and an auxiliary electrode, and a magnetic field and a flow field are combined to optimize; and performing passivation, cleaning, drying and solidification treatment on the plug shielding member after electroplating. The surface activity is improved through ultrasonic cleaning, plasma treatment and acid activation; the electric field distribution is regulated through the main electrode and the auxiliary electrode, and the magnetic field and the flow field are combined to optimize ion migration in a deep hole area, so that the uniformity of the plating layer thickness and the coverage rate are improved; the pulse current is used to refine the grain structure, so that the compactness and the mechanical strength of the plating layer are enhanced; and the corrosion resistance is improved through passivation, drying and solidification in the post-treatment, so that the technical effects of significantly improving the adhesion of the electroplating layer and the uniformity of the plating layer are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electroplating, in particular to a plating method for a plug shield. BACKGROUND

[0002] With the development of modern electronic devices towards miniaturization, high integration and high performance, the quality of the surface plating layer of the plug shield, as an important part of the electrical connector, is directly related to the anti-interference performance, corrosion resistance and service life of the device. The traditional electroplating technology mainly relies on single direct current deposition, which can basically meet the requirements in the past application scenarios, but with the increasing complexity of the geometric structure of the plug shield and the harshness of the environmental conditions, the limitations of this traditional technology are increasingly apparent.

[0003] In the prior art, the traditional electroplating process generally adopts a single main electrode direct current deposition method, mainly depositing metal ions on the surface of the plug shield through a static electric field. However, due to the non-uniformity of the electric field distribution, over-deposition is prone to occur at the edge of the plug shield, while the recess and deep hole areas are insufficiently deposited. This phenomenon is called "edge effect", which directly leads to the non-uniformity of the plating layer thickness. Non-uniform thickness not only affects the shielding performance, but also may cause product failure due to the exposure of local weak areas. Especially for plug shields with complex geometric shapes, such as structures with deep holes or multiple grooves, the traditional electroplating method has very limited coverage ability for deep holes and recessed areas. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a plating method for a plug shield, which solves the problems of insufficient adhesion and incomplete cleaning effect in the treatment of complex geometric surfaces.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: a plating method for a plug shield, comprising the following steps:

[0006] Surface pretreatment of the plug shield;

[0007] Plating the plug shield in an electrolyte, wherein the electric field distribution is regulated by the main electrode and the auxiliary electrode during the plating process, and the magnetic field and the flow field are combined for optimization;

[0008] Passivation, cleaning, drying and curing treatment of the plated plug shield.

[0009] Preferably, the surface pretreatment comprises the following steps:

[0010] Ultrasonic cleaning in an ethanol solution for 8-12 minutes at a temperature of 25-30℃;

[0011] The surface of the plug shield is treated with argon plasma, with a pressure range of 0.05 to 0.15 MPa, a power range of 50 to 150 W, and a time of 2 to 5 minutes.

[0012] Acidic activation treatment is carried out in a 10% sulfuric acid solution for 1–3 minutes at a temperature of 25–35°C.

[0013] Preferably, in the electroplating step, the main electrode is used to provide a stable current density, with a current density range of 2.0–2.5 A / dm². 2 The auxiliary electrodes are arranged on the edge and groove area of ​​the plug shield to dynamically control the local electric field. The potential range of the auxiliary electrodes is 0 to 0.5V.

[0014] Preferably, in the electroplating step, the electrolyte comprises:

[0015] Nickel sulfate, concentration 280–320 g / L;

[0016] Nickel chloride, concentration 40-50 g / L;

[0017] Boric acid, with a concentration of 25–35 g / L;

[0018] Polyethylene glycol, concentration of 40-60 ppm.

[0019] Preferably, the electroplating step uses a magnetic field to enhance ion migration. The magnetic field is generated by an electromagnetic coil, and the magnetic field strength ranges from 0.2 to 0.4 T. The direction of the magnetic field is orthogonal to the direction of the electric field.

[0020] Preferably, in the electroplating step, turbulence is generated in the deep holes and grooves of the plug shield by a microfluidic nozzle, the flow rate of the microfluidic nozzle is in the range of 0.2 to 0.5 m / s, and the nozzle spray angle is in the range of 30° to 60°.

[0021] Preferably, the electroplating step uses pulsed current for electroplating, with a pulse frequency range of 300–500 Hz and a peak current density of 2.5–3.5 A / dm³. 2 The ratio of opening time to closing time is 1:1 to 1:2.

[0022] Preferably, the electroplating time is 8 to 12 minutes, and the thickness of the final coating is controlled at 6 ± 0.5 μm.

[0023] Preferably, the passivation treatment in the post-treatment is carried out in an alkaline solution with a pH of 9 to 10, and the passivation time is 2 to 4 minutes.

[0024] Preferably, the drying process in the post-processing is carried out under constant temperature conditions of 70-90°C for 0.5-1 hour.

[0025] This invention provides an electroplating method for a plug shield. It has the following advantages:

[0026] 1. This invention employs a surface pretreatment technology solution involving cleaning, argon plasma treatment, and acid activation. Ultrasonic cleaning removes surface impurities, plasma etching enhances surface activity, and acid activation further optimizes surface roughness, achieving a significant improvement in the adhesion and uniformity of the electroplated layer. Compared to existing technologies that rely solely on chemical cleaning, this invention solves the problems of insufficient adhesion and incomplete cleaning in complex geometric surface treatments.

[0027] 2. This invention achieves electric field distribution control through the main electrode and auxiliary electrode, and enhances metal ion migration and deep hole coverage by combining the effects of magnetic field and flow field, thus significantly improving the uniformity of coating thickness and the coating coverage of deep hole areas. Compared with existing electroplating methods that only use fixed electrodes or static plating solutions, this invention solves the problems of uneven coating thickness and insufficient deep hole coverage.

[0028] 3. This invention employs a post-treatment technology combining alkaline passivation with constant-temperature drying and curing. By generating a dense protective film on the coating surface and further curing its structure, it achieves the technical effect of enhancing the corrosion resistance and stability of the coating. Compared with existing technologies that do not fully optimize the post-treatment process, this invention solves the problems of easy corrosion and poor long-term working stability of the coating in high-humidity and high-salt environments. Attached Figure Description

[0029] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example:

[0032] Please see the appendix Figure 1This invention provides an electroplating method for a plug shield, comprising the following steps: Step 1: Cleaning and activating the surface of the plug shield. The cleaning includes ultrasonic cleaning in an ethanol solution for 8-12 minutes at a temperature of 25-30°C. After cleaning, the surface is rinsed with deionized water and air-dried. The activation treatment includes treating the surface of the plug shield with argon plasma at a pressure range of 0.05-0.15 MPa and a power range of 50-150 W for 2-5 minutes to remove surface oxides and activate surface chemical activity. Subsequently, the plug shield is placed in a 10% sulfuric acid solution for acid activation treatment for 1-3 minutes at a temperature of 25-35°C to further enhance surface affinity.

[0033] Ultrasonic waves generate microbubbles through cavitation, creating strong localized impact forces on the surface of the plug shield, effectively removing oil and particles adhering to the surface. The cleaning process utilizes precise time and temperature control to prevent over-cleaning and damage to the substrate surface.

[0034] Step 2: High-energy particles in the plasma bombard the surface of the plug shield, which can peel off the oxide layer and impurities on the surface. At the same time, the physical etching process enhances the micro-roughness of the surface, providing an excellent bonding interface for subsequent electroplating.

[0035] The acidic environment provided by the sulfuric acid solution effectively removes trace impurities remaining on the surface, while simultaneously generating a highly active metal surface with a micro-rough structure, laying the foundation for the uniform growth of subsequent coatings. The pre-treated plug shield is placed in the electrolyte for electroplating. During the electroplating process, the electric field distribution is controlled through a main electrode and an auxiliary electrode. The main electrode provides a stable current density, ranging from 2.0 to 2.5 A / dm³. 2 Auxiliary electrodes are arranged on the edge and groove area of ​​the plug shield to dynamically control the local electric field. The potential range of the auxiliary electrodes is 0–0.5V. During electroplating, a magnetic field is used to enhance the migration of metal ions. This magnetic field is generated by an electromagnetic coil, with a strength range of 0.2–0.4T, and the magnetic field direction is orthogonal to the electric field direction. Furthermore, turbulence is generated in the deep holes and groove areas of the plug shield by a microfluidic nozzle. The flow rate of the microfluidic nozzle ranges from 0.2–0.5 m / s, and the nozzle spray angle ranges from 30°–60°. The electroplating is performed using pulsed current, with a pulse frequency range of 300–500 Hz and a peak current density of 2.5–3.5 A / dm³. 2 The ratio of turn-on time to turn-off time is 1:1 to 1:2. The electroplating time is 8 to 12 minutes, and the final coating thickness is controlled at 6±0.5μm.

[0036] The distribution and control of the main electrode and auxiliary electrode can effectively optimize the current distribution on complex geometric surfaces. The main electrode provides a uniform base current, while the auxiliary electrode enhances or weakens the electric field in edge and groove regions. By dynamically controlling the deposition rate of potential-balanced ions in these regions, the problem of uneven coating thickness on complex surfaces can be solved.

[0037] The magnetic field enhances the lateral migration ability of metal ions through the Lorentz force. Since the direction of the magnetic field is orthogonal to the direction of the electric field, the movement of metal ions perpendicular to the direction of the electric field is strengthened, enabling ions to reach deep holes and groove regions more uniformly, thus improving the coverage uniformity of coatings on complex geometric surfaces.

[0038] Microfluidic nozzles generate controllable fluid disturbances in critical areas, which helps to break the static boundary layer of the plating solution and improve the distribution of metal ions in the electrolyte, especially in recessed and deep hole areas. By changing the flow rate and spray angle, the ion mass transfer efficiency in these areas can be effectively improved.

[0039] By controlling the pulsed current, the current peak during the deposition stage promotes the rapid deposition of metal ions, while the off-stage allows the ions in the plating solution to redistribute in a balanced manner, inhibiting dendrite growth and bubble formation, ultimately resulting in a denser and more uniform plating layer. Step three involves passivating, cleaning, drying, and curing the electroplated plug shield. Passivation is performed in an alkaline passivation solution with a pH of 9–10 for 2–4 minutes to form a dense protective film on the surface of the plug shield. After cleaning, the plug shield is dried in a constant temperature environment of 70–90°C for 0.5–1 hour to ensure the removal of any residual liquid. Finally, curing is performed to further improve the stability of the plating layer.

[0040] The alkaline passivation solution generates a stable oxide film on the coating surface through a chemical reaction. This film has excellent corrosion resistance and can effectively protect the long-term stability of the coating in complex environments.

[0041] The cleaning process removes chemical residues from the electroplating process, preventing them from adversely affecting the performance of the plating layer; the drying process removes moisture from the surface of the plating layer at a constant temperature, preventing oxidation or stains from forming on the surface of the plating layer due to residual liquid.

[0042] The curing process further enhances the mechanical strength and corrosion resistance of the coating, while also improving its adhesion and crack resistance.

[0043] Example 1: Standard electroplating process for conventional plug shielding components. Purpose: To verify the ability of the present invention to achieve a uniform electroplating layer on conventional plug shielding components, and to solve the problem of uneven plating thickness in the background art.

[0044] Surface pretreatment cleaning: Immerse the plug shield in an ethanol solution (concentration ≥99.5%) and ultrasonically clean for 10 minutes at a temperature of 30℃. After cleaning, rinse with deionized water and air dry.

[0045] Plasma treatment: Argon gas is introduced at a pressure of 0.1 MPa, a treatment power of 100 W, and a time of 3 minutes to remove the surface oxide layer and impurities.

[0046] Acid activation: Immerse the plug shield in a 10% sulfuric acid solution for 2 minutes at a solution temperature of 30°C. After immersion, rinse with deionized water and keep moist.

[0047] Electroplating process

[0048] Electrolyte formulation:

[0049] Nickel sulfate: 300 g / L;

[0050] Nickel chloride: 45 g / L;

[0051] Boric acid: 30 g / L;

[0052] Polyethylene glycol (PEG): 50 ppm.

[0053] Electric field control:

[0054] Main electrode current density: 2.2 A / dm 2 ;

[0055] Auxiliary electrode potential range: 0.3V.

[0056] Magnetic field settings:

[0057] Magnetic field strength: 0.3T;

[0058] The direction of the magnetic field is orthogonal to the electric field.

[0059] Flow field optimization:

[0060] Microfluidic nozzle flow rate: 0.3 m / s;

[0061] Spray angle: 45°.

[0062] Pulse current setting:

[0063] Pulse frequency: 400Hz;

[0064] Peak current density: 3.0 A / dm 2 ;

[0065] The ratio of activation time to shutdown time is 1:1.

[0066] Electroplating time: 10 minutes.

[0067] Post-processing

[0068] Passivation treatment: The plug shield is placed in an alkaline passivation solution with a pH of 9 for 3 minutes.

[0069] Drying process: The drying temperature is 80℃ and the time is 1 hour.

[0070] Experimental results:

[0071] The coating thickness uniformity error is ±0.3μm;

[0072] No corrosion spots were observed after 500 hours of salt spray testing;

[0073] The coating has a smooth and dense surface, making it suitable for general applications.

[0074] Summary of the embodiments: This embodiment achieves uniform coating thickness on conventional plug shielding components by optimizing the electric field, magnetic field, and flow field. Standardized process conditions verify that the invention is applicable to electroplating requirements in typical scenarios, while also demonstrating its significant advantages in improving thickness control accuracy and corrosion resistance.

[0075] Example 2: Electroplating process for complex geometric plug shielding components. Objective: To verify the electroplating capability of the present invention on complex geometric surfaces (deep holes, grooves, etc.) and solve the problem of insufficient coverage of deep hole areas in the background technology.

[0076] Surface pretreatment

[0077] Same as Example 1, with identical specific parameters.

[0078] Electroplating process

[0079] Electrolyte formulation:

[0080] Nickel sulfate: 310 g / L;

[0081] Nickel chloride: 50 g / L;

[0082] Boric acid: 35g / L;

[0083] Polyethylene glycol (PEG): 60 ppm.

[0084] Electric field control:

[0085] Main electrode current density: 2.0 A / dm 2 ;

[0086] Auxiliary electrode potential range: 0.4V.

[0087] Magnetic field settings:

[0088] Magnetic field strength: 0.4T;

[0089] The direction of the magnetic field is orthogonal to the electric field.

[0090] Flow field optimization:

[0091] Microfluidic nozzle flow rate: 0.5 m / s;

[0092] Spray angle: 30°.

[0093] Pulse current setting:

[0094] Pulse frequency: 300Hz;

[0095] Peak current density: 3.5 A / dm 2 ;

[0096] The ratio of opening time to closing time is 1:2.

[0097] Electroplating time: 12 minutes.

[0098] The post-processing is the same as in Example 1, with the same specific parameters.

[0099] Experimental results:

[0100] The coating coverage in groove and deep hole areas is increased by 30%;

[0101] The coating thickness error is controlled within ±0.4μm;

[0102] The surface is uniform with no exposed areas.

[0103] Summary of the embodiments: This embodiment significantly improves the coverage of complex geometric surfaces by enhancing the synergistic effect of the magnetic field and the flow field. Compared with Embodiment 1, the ion migration capability in the deep hole region is significantly improved, and the coating thickness is slightly increased, verifying that the present invention is applicable to the application scenarios of complex-shaped plug shielding components.

[0104] Compared to the standard application scenario in Example 1, this example optimizes the auxiliary electrode, flow field turbulence, and magnetic field strength for complex geometries to improve the coverage of ions in deep holes and groove regions, thereby making up for the shortcomings of traditional technologies in complex surface treatment.

[0105] Example 3: Optimized high-performance electroplating process. Objective: To verify the ability to improve the corrosion resistance of the coating under more demanding working conditions and to solve the problem of insufficient corrosion resistance in the existing technology.

[0106] Surface pretreatment

[0107] Same as Example 1, with identical specific parameters.

[0108] Electroplating process

[0109] Electrolyte formulation:

[0110] Nickel sulfate: 290 g / L;

[0111] Nickel chloride: 50 g / L;

[0112] Boric acid: 30 g / L;

[0113] Add sodium chloride: 0.02M (to improve the conductivity of the solution).

[0114] Electric field control:

[0115] Main electrode current density: 2.5 A / dm 2 ;

[0116] Auxiliary electrode potential range: 0.3V.

[0117] Magnetic field settings:

[0118] Magnetic field strength: 0.2T;

[0119] The direction of the magnetic field is orthogonal to the electric field.

[0120] Flow field optimization:

[0121] Microfluidic nozzle flow rate: 0.4 m / s;

[0122] Spray angle: 60°.

[0123] Pulse current setting:

[0124] Pulse frequency: 500Hz;

[0125] Peak current density: 3.0 A / dm 2 ;

[0126] The ratio of activation time to shutdown time is 1:1.

[0127] Electroplating time: 10 minutes.

[0128] Post-processing

[0129] Passivation treatment: The plug shield is placed in a passivation solution with a pH of 10 for 4 minutes.

[0130] Drying and curing treatment: Drying temperature is 90℃ for 1 hour; followed by curing at 200℃ for 20 minutes.

[0131] Experimental results:

[0132] No corrosion was observed after 1000 hours of salt spray testing;

[0133] The coating adhesion is improved by 25%;

[0134] The micro porosity is reduced by 50%, and the wear resistance of the coating surface is enhanced.

[0135] Summary of the Examples: This example significantly improves the corrosion resistance and mechanical strength of the coating by optimizing the electrolyte and post-treatment process. Compared with Examples 1 and 2, it is suitable for plug shielding applications under harsh conditions such as high humidity and high salinity.

[0136] Compared to Examples 1 and 2, this example adds sodium chloride to the electrolyte to enhance conductivity, and also uses a higher post-treatment temperature and curing step, thereby further improving the density and corrosion resistance of the coating.

[0137] Comparative Example 1:

[0138] Surface pretreatment

[0139] Cleaning involves simple rinsing with distilled water, without ultrasonic cleaning or plasma treatment; surface impurities are removed only by wiping with solvent.

[0140] The acid activation treatment uses a 5% sulfuric acid solution and the activation time is 1 minute, without temperature control.

[0141] Electroplating process

[0142] Electrolyte formulation: Same as in Example 1.

[0143] Electric field control: Only a single main electrode is used, with a current density of 2.2 A / dm². 2 No auxiliary electrode control.

[0144] Magnetic field setting: No magnetic field applied.

[0145] Flow field optimization: The electrolyte is stationary with no fluid disturbance.

[0146] Pulse current setting: Uses constant DC current, without pulse current regulation.

[0147] Electroplating time: 10 minutes.

[0148] Post-processing

[0149] The passivation solution has a pH of 8 and a treatment time of 2 minutes.

[0150] Drying conditions: air drying at room temperature, not constant temperature drying.

[0151] Surface pretreatment

[0152] The surface is rinsed with distilled water; there is no ultrasonic cleaning or plasma treatment.

[0153] The acid activation is consistent with that in Example 2.

[0154] Electroplating process

[0155] Electrolyte formulation: Same as in Example 2.

[0156] Electric field control: Main electrode and auxiliary electrode are used, but the auxiliary potential is not optimized for the groove and deep hole areas. The auxiliary electrode potential is fixed at 0.2V.

[0157] Magnetic field setting: A magnetic field is used, but the intensity is fixed at 0.1T and there is no dynamic adjustment.

[0158] Flow field optimization: Microfluidic nozzles are removed, electrolyte flow is undisturbed, and ion transport is achieved solely through natural convection.

[0159] Pulse current setting: Same as in Example 2.

[0160] Electroplating time: 12 minutes.

[0161] The post-treatment passivation and drying processes are the same as in Example 2.

[0162] Comparative Example 3:

[0163] The surface pretreatment is the same as in Example 3.

[0164] Electroplating process

[0165] Electrolyte formulation: No sodium chloride is added; only nickel sulfate, nickel chloride, and boric acid are used.

[0166] Electric field control: The main electrode current density is fixed at 2.2 A / dm. 2 No auxiliary electrode.

[0167] Magnetic field setting: No magnetic field applied.

[0168] Flow field optimization: microfluidic nozzles are removed, allowing for natural convection of the electrolyte.

[0169] Pulse current setting: Same as in Example 3.

[0170] Electroplating time: 10 minutes.

[0171] Post-processing

[0172] The passivation solution had a pH of 8.5 and a treatment time of 1 minute.

[0173] The drying temperature was lowered to 60℃ for 30 minutes;

[0174] No curing process required.

[0175] Comparative Example 4: Another comparative experiment based on Example 1

[0176] The surface pretreatment is the same as in Example 1.

[0177] Electroplating process

[0178] Electrolyte formulation: Same as in Example 1.

[0179] Electric field control: Same as in Example 1.

[0180] Magnetic field settings: Same as in Example 1.

[0181] Flow field optimization: Same as in Example 1.

[0182] Current setting: Use constant DC current with a current density of 2.5 A / dm³. 2 .

[0183] Electroplating time: 10 minutes.

[0184] The post-processing is the same as in Example 1.

[0185] Comparative Example 5: The surface pretreatment was the same as in Example 2.

[0186] Electroplating process

[0187] Electrolyte formulation: Same as in Example 2.

[0188] Electric field control: Same as in Example 2.

[0189] Magnetic field settings: The magnetic field is fixed at 0.2T, and the magnetic field strength has not been optimized for complex surface areas.

[0190] Flow field optimization: microfluidic nozzles are removed, allowing for natural convection of the electrolyte.

[0191] Pulse current setting: Same as in Example 2.

[0192] Electroplating time: 12 minutes.

[0193] The post-processing is the same as in Example 2.

[0194] Experimental Example 1:

[0195] The purpose of this experiment is to verify the ability of the present invention to achieve a uniform coating on the surface of the plug shield. By comparing the coating thickness error of the embodiments and the comparative examples, the effects of multi-physics field synergistic optimization and flow field disturbance technology in improving coating uniformity are highlighted.

[0196] Experimental materials and equipment

[0197] Plug shielding samples: conventional plug shielding and complex geometry plug shielding;

[0198] Laser thickness gauge (resolution: 0.1μm);

[0199] Samples prepared in Examples 1 and 2;

[0200] Samples prepared in Comparative Example 1 and Comparative Example 2.

[0201] Experimental steps

[0202] Sample preparation

[0203] The plug shielding samples prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were taken respectively.

[0204] Each sample group includes five representative plug shields from five different locations (flat surface, edge, and groove).

[0205] Measurement location selection

[0206] Ten test points were selected at the plane, edge, and groove of each sample, for a total of 30 test points for measurement.

[0207] Mark the location of each test point to ensure the repeatability of the measurement.

[0208] Thickness measurement: The coating thickness at each test point was measured using a laser thickness gauge, and the average value of three repeated measurements was recorded.

[0209] Data analysis: Calculate the thickness uniformity error (the difference between the maximum and minimum thickness) for each group of samples.

[0210] By comparing the thickness errors of the embodiments and the comparative examples, the effects of multiphysics optimization and flow field disturbance on uniformity are analyzed.

[0211]

[0212] Experimental data

[0213] Experiment Summary

[0214] This experiment, by comparing the thickness uniformity of the examples and comparative examples, verifies the technical advantages of this invention in improving the uniformity of the coating thickness of plug shielding components. Experimental results show that the thickness errors of Examples 1 and 2 are 0.6 μm and 0.5 μm, respectively, significantly lower than the 1.7 μm and 1.5 μm of Comparative Examples 1 and 2. The results indicate that multiphysics-based synergistic optimization and flow field perturbation techniques have significant advantages in reducing coating thickness error and improving uniformity.

[0215] The multiphysics optimization technique of this invention creates a dynamic electric field distribution between the main electrode and the auxiliary electrode, effectively reducing excessive deposition in the edge region and insufficient deposition in the groove region. Simultaneously, the orthogonal interaction of the magnetic and electric fields promotes ion migration through the Lorentz force, further improving the uniformity of metal ion distribution on complex surfaces. The introduction of flow field disturbance, through localized turbulence generated by the microfluidic nozzle, eliminates the boundary layer effect of the plating solution, increasing the ion transport efficiency in deep holes and groove regions.

[0216] The test results of Comparative Examples 1 and 2 show that, in the absence of multi-physics synergistic optimization and flow field perturbation, the deposition in the edge region is too thick, while the deposition in the groove region is insufficient. The non-uniformity of the coating thickness mainly stems from the limitations of traditional static electric field distribution and natural convection, which cannot solve the problem of uneven ion distribution under complex surface geometries. In contrast, the present invention, through dynamic control in the embodiments, significantly improves the uniformity of the coating, solving a key pain point in traditional electroplating processes.

[0217] Experimental Example 2:

[0218] Deep hole area coating coverage test

[0219] Experimental instructions

[0220] Experimental Objective

[0221] To verify the technical advantages of this invention in coating coverage on complex geometric surfaces (especially deep holes and groove areas), the influence of multi-physics field optimization (magnetic field and flow field) on coating coverage performance is analyzed by comparing the samples of the embodiments and comparative examples.

[0222] Experimental materials and equipment

[0223] Plug shield sample: Plug shield with complex geometry;

[0224] Scanning electron microscope (SEM): resolution 0.01 μm;

[0225] The sample prepared in Example 2;

[0226] Samples prepared in Comparative Example 2 and Comparative Example 5.

[0227] Experimental steps

[0228] Sample preparation

[0229] The complex geometric plug shields prepared in Example 2, Comparative Example 2, and Comparative Example 5 were used respectively.

[0230] Each sample set includes plug shields with diameters ranging from 1 mm to 2 mm in the deep hole area, ensuring consistency across complex surfaces tested.

[0231] Coating morphology observation

[0232] Scanning electron microscopy (SEM) was used to photograph the coating morphology in the deep hole area to observe the continuity, thickness, and presence of uncovered areas on the deep hole surface.

[0233] Five observation points were randomly selected inside each deep hole, and the coating thickness at each point was measured and recorded.

[0234] Coverage calculation

[0235] Based on SEM images, image analysis software was used to calculate the coverage of the coating on the deep hole surface (the ratio of the coating area to the total surface area of ​​the deep hole).

[0236] Calculate the average coverage for each sample group.

[0237] Experimental data.

[0238]

[0239]

[0240] This experiment, by comparing the coating coverage of Example 2 with Comparative Examples 2 and 5, verifies the technical advantages of this invention in electroplating deep holes and complex geometric surfaces. The coating coverage of the sample in Example 2 reached over 98%, while the coverage of Comparative Examples 2 and 5 were 72% and 84%, respectively, significantly lower than that of Example 2. This result indicates that multiphysics optimization technology (magnetic field and flow field) plays a crucial role in improving the coating coverage in deep hole regions.

[0241] The magnetic field optimization of this invention enhances the lateral migration ability of metal ions through the Lorentz force, enabling them to be more uniformly distributed inside the deep holes. Meanwhile, the flow field disturbance, through a microfluidic nozzle, breaks the static boundary layer of the plating solution, further improving the ion transport efficiency in the deep hole region. The synergistic effect of these two factors creates a uniform deposition environment within the complex geometry, effectively solving the problem of insufficient deposition in deep hole regions in traditional electroplating.

[0242] The experimental results of Comparative Example 2 show that, due to the lack of flow field perturbation technology, the metal ion concentration inside the deep hole cannot be kept uniform, resulting in a significant decrease in coating coverage. While Comparative Example 5 employed flow field perturbation technology, it did not apply a magnetic field, thus limiting ion migration within the deep hole, leading to uneven coating thickness and uncovered areas. In contrast, this invention, through the synergistic optimization of the magnetic field and flow field in Example 2, fundamentally improves the coverage performance of complex geometric surfaces and deep hole regions.

[0243] Furthermore, thickness measurements in the experimental data further support this conclusion: the coating thickness uniformity of Example 2 is significantly higher than that of Comparative Example 2 and Comparative Example 5, indicating that multiphysics optimization can effectively improve the quality and continuity of the coating in the deep hole region. This experimental comparison fully verifies the technical advantages and practical application value of the present invention in complex surface applications.

[0244] Experiment Example 3: Coating Density Test

[0245] Experimental instructions

[0246] Experimental Objective

[0247] To verify the optimization effect of the pulsed current process of this invention on the density and grain uniformity of the coating, the role of pulsed current in improving the coating quality was analyzed by comparing Example 1 and Comparative Example 4.

[0248] Experimental materials and equipment

[0249] Plug shield sample: conventional geometry plug shield;

[0250] X-ray diffractometer (XRD): used to test the grain size and crystal orientation of coatings;

[0251] Microporosity analysis equipment: used to calculate the porosity of coatings;

[0252] The sample prepared in Example 1;

[0253] The sample prepared in Comparative Example 4.

[0254] Experimental steps

[0255] Sample preparation

[0256] Five samples of conventional geometric plug shielding components prepared in Example 1 and Comparative Example 4 were taken from each group to ensure that the same process conditions and materials were used.

[0257] Grain size testing

[0258] The grain size of the sample coating was measured using an X-ray diffractometer (XRD).

[0259] The scanning range was set to 2θ = 20°-90°, the peak position and full width at half maximum (FWHM) were recorded, and the grain size was calculated (using the Scherrer formula).

[0260] Three points were selected in the planar region of each sample, and the average value was taken.

[0261] Porosity test

[0262] The porosity of the sample coating was measured using a microporous analysis device.

[0263] Five regions were selected on the sample surface, and the ratio of pore area to total surface area was calculated using image processing software.

[0264] Data Analysis

[0265] By comparing the grain size uniformity and porosity of the examples and comparative examples, the effect of pulsed current on optimizing coating density is analyzed.

[0266] Experimental data.

[0267]

[0268] This experiment verified the effect of pulsed current in improving the density and grain uniformity of the coating by comparing the grain size and porosity of the coatings in Example 1 and Comparative Example 4. The experimental results showed that the average grain size of the sample in Example 1 was 46.2 nm, significantly smaller than that of Comparative Example 4 (70.3 nm), and the porosity was also significantly reduced to 0.93%, far lower than the 3.17% of Comparative Example 4. The results indicate that pulsed current has a significant optimizing effect on the coating structure.

[0269] This invention employs pulsed current technology, controlling the deposition rate of metal ions by adjusting the peak current density and pulse switching time. During the energizing phase, metal ions deposit at a high kinetic rate to form dense crystals, while during the de-energizing phase, the metal ions in the electrolyte are redistributed uniformly, avoiding coarse grains and structural defects caused by excessively rapid deposition. Simultaneously, the transient electric field fluctuations of the pulsed current effectively suppress dendrite growth and porosity formation, resulting in a denser and more uniform coating.

[0270] The experimental results of Comparative Example 4 show that under constant DC current conditions, metal ions continuously deposit at an excessively rapid rate, preventing complete rearrangement of grains during growth and resulting in coarse crystal particles. Simultaneously, the lack of a turn-off phase in the DC current restricts the transport of metal ions in the plating solution, easily leading to the formation of micropores in the coating and reducing overall density. These results clearly demonstrate that constant current cannot effectively optimize the internal structure of the coating.

[0271] The comparative analysis in this experiment fully demonstrates the core role of pulsed current technology in this invention. Compared with traditional DC electroplating, pulsed current achieves finer grain control and lower porosity by dynamically regulating the ion deposition process, significantly improving the density and mechanical strength of the coating, thereby better meeting the practical application requirements of high-performance plug shielding components.

[0272] Experiment Example 4: Corrosion Resistance Test

[0273] The purpose of this experiment is to verify the technical advantages of the present invention in improving the corrosion resistance of the coating. By comparing Example 3 and Comparative Example 3, the contribution of post-treatment optimization (passivation, drying and curing) to the corrosion resistance of the coating is analyzed.

[0274] Experimental materials and equipment

[0275] Plug shield sample: conventional geometry plug shield;

[0276] Salt spray test chamber: conforms to ASTM B117 standard;

[0277] The sample prepared in Example 3;

[0278] The sample prepared in Comparative Example 3.

[0279] Experimental steps

[0280] Sample preparation

[0281] Five plug shielding samples were taken from both Example 3 and Comparative Example 3 to ensure the same plating thickness and pre-process conditions.

[0282] Salt spray test

[0283] A corrosive environment was simulated in the salt spray test chamber, with the test solution being a 5% sodium chloride solution and the temperature set at 35℃.

[0284] According to ASTM B117 standard, the sample was placed in a salt spray environment for 500 hours.

[0285] Corrosion area calculation

[0286] Samples were removed every 100 hours, cleaned and dried, and then images of the sample surface were taken using a high-resolution digital camera.

[0287] The corrosion area ratio (the ratio of the corrosion area to the total surface area) is calculated using image processing software.

[0288] Data Analysis

[0289] The corrosion area ratio of the comparative examples and the control examples after 500 hours of salt spray testing was compared to analyze the effect of post-treatment on the anti-corrosion performance of the coating.

[0290] Experimental data

[0291]

[0292] This experiment, by comparing the salt spray test results of Example 3 and Comparative Example 3, verified the significant effect of optimized post-treatment technology (passivation, drying, and curing) on ​​improving the corrosion resistance of the coating. The experimental results showed that the corrosion area ratio in Example 3 was only 1.0% after 500 hours of salt spray testing, while the corrosion area ratio in Comparative Example 3 was as high as 8.5%. The results indicate that post-treatment optimization technology plays an important role in improving the corrosion resistance of the coating.

[0293] This invention employs alkaline passivation in the post-treatment process, generating a dense oxide film through a chemical reaction. This oxide film not only improves the corrosion resistance of the coating but also provides an additional barrier protection. Furthermore, the isothermal drying step further removes residual liquids and gases from the coating surface, reducing micropore formation and preventing the penetration of corrosive media. The curing treatment, through heating, promotes the structural stability and chemical bond strengthening within the coating, significantly improving its durability in high-salt and high-humidity environments.

[0294] The results of the comparative example show that, without optimized post-treatment, the coating surface is prone to the formation of micropores and defects. These defects become channels for corrosive media penetration, accelerating the corrosion of the coating. Simultaneously, due to the lack of effective curing treatment, the internal structure of the coating is relatively loose, making it difficult to resist corrosion under prolonged salt spray conditions. This result contrasts sharply with Example 3, further demonstrating the crucial role of post-treatment optimization in corrosion resistance.

[0295] Through comparative analysis of this experiment, it is clear that this invention, through scientifically designed passivation, drying, and curing steps, optimizes the corrosion resistance of the coating from both physical and chemical perspectives. This solves the problem of easy corrosion and performance degradation of coatings in high-salt and high-humidity environments in traditional processes, providing technical assurance for high-durability plug shielding components. The significant differences in the experimental data fully demonstrate the superiority of this invention in practical applications.

[0296] Experiment Example 5:

[0297] Real-world application performance testing

[0298] Experimental Objective

[0299] To verify the comprehensive performance of the present invention in practical applications, including the adhesion, wear resistance and stability of the coating under high temperature and high humidity conditions, the multiphysics optimization technology and post-processing process are analyzed to improve the performance of practical applications by comparing Example 1 and Example 3 with Comparative Example 1 and Comparative Example 3.

[0300] Experimental materials and equipment

[0301] Plug shield sample: Standard structure plug shield;

[0302] Tensile testing machine: used to test bonding strength;

[0303] Abrasion testing machine: Used to test the abrasion resistance of coatings;

[0304] High temperature and high humidity cycling test equipment: used to test the thermal cycling stability of coatings;

[0305] Samples prepared in Examples 1 and 3;

[0306] Samples prepared in Comparative Example 1 and Comparative Example 3.

[0307] Experimental steps

[0308] Sample preparation

[0309] Five plug shields were prepared according to Examples 1, 3, 1, and 3 respectively, ensuring that the same substrate and coating thickness were used.

[0310] Bonding force test

[0311] The adhesion between the coating and the substrate was tested using a tensile testing machine.

[0312] Tensile tests were performed on each sample, and the critical tensile force (N / cm) for coating detachment was recorded. 2 ).

[0313] Each sample was tested three times, and the average value was taken.

[0314] Abrasion resistance test

[0315] The coating surface was subjected to friction testing using an abrasion testing machine.

[0316] Each sample was subjected to 2000 reciprocating friction cycles, with the friction head applying a load of 2N and a friction speed of 60 cycles / minute.

[0317] After the test is completed, observe the wear condition of the coating surface and calculate the wear area.

[0318] Thermal cycling test

[0319] The sample was subjected to 10 thermal cycling tests using a high temperature and high humidity cycling test device.

[0320] Each cycle includes a 100°C high-temperature environment and a 40°C high-humidity environment, each lasting 30 minutes.

[0321] After the test, record whether cracks, peeling and other defects appear on the coating surface.

[0322]

[0323]

[0324] This experiment compared the bonding strength, wear resistance, and thermal cycling stability of the examples and comparative examples to verify the improvement of practical application performance by multiphysics optimization technology and post-processing. The experimental results show that the overall performance of Examples 1 and 3 is significantly better than that of Comparative Examples 1 and 3, especially in terms of bonding strength and wear resistance, demonstrating a clear technical advantage. Example 3 achieved a bonding strength of 135 N / cm. 2 The wear area is only 0.6mm. 2 It exhibits extremely high stability, while Comparative Example 3 has poor bonding strength and wear resistance, with obvious cracking and peeling.

[0325] This invention achieves a uniform electric field and a stable flow field through multiphysics field optimization, resulting in more uniform and dense deposition of the coating on the substrate surface. Pulsed current technology further enhances the control over metal ion deposition, refines grain size, and strengthens the mechanical adhesion of the coating. During post-processing, passivation generates a dense protective film on the coating surface, and drying and curing further improve the coating's wear resistance and crack resistance. This multi-layered optimization process ensures the reliability of the coating in practical applications.

[0326] The experimental results of Comparative Examples 1 and 3 show that, in the absence of multiphysics optimization technology, the non-uniformity of the electric field distribution leads to a decrease in coating adhesion, an increase in surface defects, and a reduction in wear resistance. Furthermore, the unoptimized post-processing results in more micropores and cracks on the coating surface, making it prone to peeling and cracking during thermal cycling tests, and unable to withstand the challenges of high-temperature and high-humidity environments.

[0327] The comparative results of this experiment fully demonstrate the significant effect of this invention in improving the overall performance of the coating. Improved adhesion and wear resistance make the plug shielding component more suitable for high-load and long-life applications, while thermal cycling stability verifies the reliability of the coating under extreme environments, providing strong support for practical industrial applications. The significant differences in the experimental data indicate that this invention has strong practical application value and solves the technical bottleneck of insufficient durability in traditional processes.

[0328] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for electroplating a plug shield, characterized in that, Includes the following steps: S1. Perform surface pretreatment on the plug shield; S2. Placing the plug shield in an electrolyte for electroplating, wherein the electric field distribution is controlled by the main electrode and the auxiliary electrode during the electroplating process, and optimized by combining the magnetic field and the flow field. The main electrode has a current density ranging from 2.0 to 2.5 A / dm²; the auxiliary electrode has a potential ranging from 0 to 0.5 V; the magnetic field is generated by an electromagnetic coil with a magnetic field strength ranging from 0.2 to 0.4 T, and the magnetic field direction is orthogonal to the electric field direction; the flow field is generated by a microfluidic nozzle in the deep holes and grooves of the plug shield, with a flow velocity ranging from 0.2 to 0.5 m / s and a spray angle ranging from 30° to 60°; during electroplating, pulsed current is used, with a pulse frequency ranging from 300 to 500 Hz, a peak current density of 2.5 to 3.5 A / dm², and an on-time to off-time ratio of 1:1 to 1:2; S3. Passivate, clean, dry and cure the electroplated plug shielding; The surface pretreatment includes the following steps: Ultrasonic cleaning was performed in an ethanol solution for 8–12 minutes at a temperature of 25–30°C. The surface of the plug shield is treated with argon plasma, with a pressure range of 0.05 to 0.15 MPa, a power range of 50 to 150 W, and a time of 2 to 5 minutes. Acid activation treatment is carried out in a 10% sulfuric acid solution for 1 to 3 minutes at a temperature of 25 to 35°C. In the electroplating step, the electrolyte comprises the following components: Nickel sulfate, concentration 280–320 g / L; Nickel chloride, concentration 40-50 g / L; Boric acid, with a concentration of 25–35 g / L; Polyethylene glycol, concentration of 40-60 ppm.

2. The electroplating method for a plug shield according to claim 1, characterized in that, The electroplating time is 8 to 12 minutes, and the final coating thickness is controlled at 6 ± 0.5 μm.

3. The electroplating method for a plug shield according to claim 1, characterized in that, The passivation treatment in S3 is carried out in an alkaline solution with a pH of 9 to 10, and the passivation time is 2 to 4 minutes.

4. The electroplating method for a plug shield according to claim 1, characterized in that, The drying process in S3 is carried out under constant temperature conditions of 70-90°C for 0.5-1 hour.

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