Continuous selective nickel-tin electroplating method and system for precise electronic element

Abstract

The invention relates to the technical field of metal surface treatment, in particular to a continuous selective nickel-tin electroplating method and system for a precise electronic element, and the method is used for realizing high-precision selective tin plating of a specific area and ensuring that a plating layer (especially a local plating area) has excellent binding force, uniformity and compactness; and through optimized process design and pollution control, the overall performance and the product yield of the plating layer are improved.

Description

Technical Field

[0001] This application relates to the field of metal surface treatment technology, and in particular to a continuous selective electroplating method and system for precision electronic components using nickel-tin. Background Technology

[0002] As electronic products become smaller and more reliable, higher requirements are placed on the plating layers of precision electronic components (such as IC pins and high-speed connectors): they need to possess excellent corrosion resistance, solderability, abrasion resistance, and stable contact resistance. A common combination is a nickel layer as a barrier and abrasion-resistant layer, and a tin layer as a solderable and corrosion-resistant layer.

[0003] The main technical challenges currently facing the industry include:

[0004] 1. Electroplating requirements for functional areas: Many components only need to be tin-plated in specific functional areas (such as contact points), while non-functional areas need to retain the original material with corrosion resistance. Traditional full plating methods waste materials, increase post-processing costs, and may affect assembly.

[0005] 2. Unstable coating adhesion and quality: Especially in localized plating areas, due to incomplete pretreatment or insufficient activation, problems such as poor coating adhesion, blistering, and localized lack of coating are easily caused.

[0006] 3. Long process flow and difficulty in controlling cross-contamination: The multi-stage electroplating and cleaning processes are connected in series, and nickel and tin solutions are prone to cross-contamination, resulting in fogging of the plating layer, pinholes, and reduced corrosion resistance.

[0007] 4. Difficulty in achieving high-temperature performance: Ordinary nickel plating may have insufficient physical properties (such as hardness and heat resistance) in subsequent high-temperature welding or usage environments, affecting the reliability of components.

[0008] While existing technologies include localized electroplating (such as spot plating and brush plating) and continuous electroplating lines, the two are usually separated, or the localized plating function is not deeply integrated with a complete and precise pre- and post-processing process, making it difficult to achieve high-efficiency, high-quality, and high-stability continuous production. Summary of the Invention

[0009] The present invention aims to overcome the shortcomings of the prior art and provide an efficient, stable, and high-quality continuous selective electroplating method and system for nickel and tin.

[0010] In a first aspect, this application provides a method for continuous selective electroplating of nickel and tin, comprising the following steps:

[0011] Step 1: Three-stage deep degreasing and activation treatment;

[0012] Step 2: Multi-level gradient nickel plating treatment;

[0013] Step 3: Selective tin plating;

[0014] Step 4: Efficient post-processing and sealing;

[0015] The selective tin plating process includes the step of selectively electroplating the front and back sides of the workpiece using a mask device.

[0016] Furthermore, the sequence of the three-stage deep degreasing and activation treatment is as follows:

[0017] Ultrasonic degreasing → cathodic electrolytic degreasing → anodic electrolytic degreasing → two-stage water washing → electrolytic activation → chemical activation → two-stage water washing.

[0018] Furthermore, the sequence of the multi-level gradient nickel electroplating process is as follows:

[0019] Pre-plating nickel → correcting nickel → nickel plating → high-temperature nickel → three-stage countercurrent water washing;

[0020] The high-temperature nickel is processed at a temperature of 60-70°C.

[0021] Furthermore, the efficient post-processing and sealing includes:

[0022] Neutralization → Ultrasonic hot water washing → Sealing → Water washing → Drying;

[0023] The temperature of the ultrasonic hot water wash is 60-80℃, and the temperature of the sealing is 80-90℃.

[0024] Furthermore, the selective tin plating process includes:

[0025] The selective tin plating process is configured with a parallel and switchable first tin plating line and a second tin plating line.

[0026] The first tin plating line performs localized selective electroplating;

[0027] The second tin plating line performs overall full-surface electroplating.

[0028] Secondly, this application provides a continuous selective electroplating system, comprising:

[0029] The production line is sequentially equipped with a three-stage deep degreasing and activation module, a multi-stage gradient nickel electroplating module, a selective tin plating module, a high-efficiency post-treatment and sealing module, and an automated conveying control module.

[0030] The three-stage deep degreasing and activation module includes an ultrasonic degreasing tank, a cathode electrolytic degreasing tank, an anodic electrolytic degreasing tank, a first water washing tank group, an electrolytic activation tank, a chemical activation tank, and a second water washing tank group; the three-stage deep degreasing and activation module is used to perform three-stage deep degreasing and activation on the workpiece.

[0031] The multi-level gradient nickel electroplating module includes a pre-plating nickel tank, a correcting nickel tank, a nickel plating tank, a high-temperature nickel tank, a third water washing tank group, and a pre-plating acid activation tank; the multi-level gradient nickel electroplating module is used to perform multi-level gradient nickel electroplating on the workpiece.

[0032] The selective tin plating module includes a first tin plating line (a partial tin plating tank integrating a precision mask alignment device) and a second tin plating line (a full tin plating tank) arranged in parallel, as well as a switching mechanism for guiding the workpiece to one of the lines; the selective tin plating module is used to perform selective tin plating operations on the workpiece.

[0033] The high-efficiency post-processing and sealing module includes a neutralization tank, an ultrasonic hot water washing tank, a sealing tank, a fourth water washing tank group, and a drying device; the high-efficiency post-processing and sealing module is used to perform high-efficiency post-processing and sealing operations on the workpiece.

[0034] The automated conveying control module is used to transport the workpiece throughout the entire line, as well as the power supply, filtration, heating, control and detection units corresponding to each process tank.

[0035] Furthermore, the first tin plating line includes a precision mask alignment device for masking and electroplating specific areas on the front and back of the workpiece.

[0036] Furthermore, each tank in the multi-level gradient nickel electroplating module is equipped with an independent temperature control, filtration, stirring, and power supply system.

[0037] The above technical solution adopted in this application has the following advantages:

[0038] 1. Achieves high precision and high efficiency in flexible compatibility between local and overall electroplating: By integrating a local tin plating line with a precision mask, it is possible to flexibly choose to produce local or full-plated products on the same production line, which meets the diverse functional requirements of modern electronic components, saves precious metal consumables, and reduces subsequent processing steps.

[0039] 2. Significantly improves the adhesion and overall quality of the coating: The combination of "three-stage deep degreasing and activation" and "multi-stage gradient nickel electroplating" processes provides a near-ideal substrate for the coating (especially the localized plating areas), ensuring extremely strong adhesion within the nickel layer and between the nickel and tin layers, effectively avoiding defects such as peeling and blistering.

[0040] 3. Optimized plating performance: The "high-temperature nickel" process improves the reliability of the nickel substrate in high-temperature environments; the combined post-treatment of "ultrasonic hot water washing" and "high-temperature sealing" greatly enhances the cleanliness, corrosion resistance and anti-discoloration ability of the tin plating layer, resulting in good stability of the product during long-term storage and use.

[0041] 4. Enhanced process stability and contamination control: The reasonable process design, multi-stage countercurrent water washing and independent plating tank management effectively control cross-contamination between different plating solutions (such as nickel and tin), reduce production and maintenance costs, and improve the consistency of product yield.

[0042] 5. Suitable for automated continuous production: The entire process is coherent, easy to achieve fully automated control, has high production efficiency, and is suitable for large-scale industrial applications. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A flowchart of a continuous selective nickel-tin electroplating method provided in one embodiment of this application;

[0045] Figure 2 This is a schematic diagram of a continuous selective electroplating system provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0047] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0048] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0049] As electronic products become smaller and more reliable, higher requirements are placed on the plating layers of precision electronic components (such as IC pins and high-speed connectors): they need to possess excellent corrosion resistance, solderability, abrasion resistance, and stable contact resistance. A common combination is a nickel layer as a barrier and abrasion-resistant layer, and a tin layer as a solderable and corrosion-resistant layer.

[0050] The main technical challenges currently facing the industry include:

[0051] 1. Electroplating requirements for functional areas: Many components only need to be tin-plated in specific functional areas (such as contact points), while non-functional areas need to retain the original material with corrosion resistance. Traditional full plating methods waste materials, increase post-processing costs, and may affect assembly.

[0052] 2. Unstable coating adhesion and quality: Especially in localized plating areas, due to incomplete pretreatment or insufficient activation, problems such as poor coating adhesion, blistering, and localized lack of coating are easily caused.

[0053] 3. Long process flow and difficulty in controlling cross-contamination: The multi-stage electroplating and cleaning processes are connected in series, and nickel and tin solutions are prone to cross-contamination, resulting in fogging of the plating layer, pinholes, and reduced corrosion resistance.

[0054] 4. Difficulty in achieving high-temperature performance: Ordinary nickel plating may have insufficient physical properties (such as hardness and heat resistance) in subsequent high-temperature welding or usage environments, affecting the reliability of components.

[0055] While existing technologies include localized electroplating (such as spot plating and brush plating) and continuous electroplating lines, the two are usually separated, or the localized plating function is not deeply integrated with a complete and precise pre- and post-processing process, making it difficult to achieve high-efficiency, high-quality, and high-stability continuous production.

[0056] Based on this, this application provides an efficient, stable, and high-quality continuous selective nickel-tin electroplating method and system. Its core objectives include: achieving high-precision selective tin plating in specific areas; ensuring excellent adhesion, uniformity, and density of the plating layer (especially in localized plating areas); and improving the overall performance of the plating layer and product yield through optimized process design and contamination control.

[0057] For specific implementation details, please refer to the following examples.

[0058] Figure 1 This is a flowchart illustrating a continuous selective electroplating method for nickel-tin provided in one embodiment of this application. Figure 1 As shown, the method includes:

[0059] S101, Three-stage deep degreasing and activation treatment;

[0060] Specifically, the workpiece to be plated is subjected to ultrasonic degreasing → cathodic electrolytic degreasing → anodic electrolytic degreasing → water washing → electrolytic activation → chemical activation → water washing in sequence.

[0061] This combined process, through the alternating action of physical ultrasound, electrochemical cathodic hydrogen evolution and anodic oxidation, and supplemented by two-stage activation, can thoroughly remove oil stains, oxide films and microscopic impurities from the workpiece surface, especially providing a highly clean and highly active substrate for subsequent local plating areas.

[0062] S102, multi-level gradient nickel plating treatment;

[0063] Specifically, the workpiece treated with S1 will be subjected to pre-nickel plating → nickel correction → nickel plating → high-temperature nickel plating → water washing in sequence.

[0064] Wherein: the pre-plating of nickel uses a low current density to form a thin nickel underlayer with strong adhesion and density.

[0065] The corrected nickel plating is applied using a medium current density to level and repair the pre-plated layer.

[0066] The nickel plating serves as the main coating, providing the body thickness and resistance to wear and corrosion.

[0067] The high-temperature nickel plating is operated at a relatively high temperature (60-70℃) and under a specific plating solution system to form a nickel layer with higher hardness, lower internal stress, and better heat resistance, providing a guarantee for subsequent welding or high-temperature applications. This multi-level gradient design achieves step-by-step optimization of the nickel layer performance.

[0068] S103, Selective tin plating treatment;

[0069] Specifically, the workpiece treated with S2 undergoes acid activation (before tin plating) and then proceeds to the tin plating process; the tin plating process is equipped with at least two independently controlled electroplating lines:

[0070] The first tin plating line employs a precision mask device to achieve selective localized electroplating (mold plating) on ​​specific areas of the workpiece's front and back sides. The mask and workpiece are aligned with high precision, and the non-plating areas are completely masked.

[0071] The second tin plating line is used for full-surface electroplating of the entire workpiece.

[0072] The workpiece can be automatically selected to enter the first or second tin plating line according to the preset program.

[0073] After tin plating, it is washed with water.

[0074] S104, High-efficiency post-processing and sealing;

[0075] Specifically, the tin-plated workpiece undergoes the following steps in sequence: neutralization → ultrasonic hot water washing → sealing → water washing → drying. The ultrasonic hot water washing is performed at 60-80℃, utilizing the combined effects of ultrasonic cavitation and hot water to thoroughly remove residual plating solution and salts from workpiece gaps and mask contact areas. The sealing process employs high-temperature (80-90℃) sealing treatment to form a dense protective film on the tin layer surface, significantly improving the plating's corrosion resistance and anti-discoloration ability.

[0076] Product Results: The resulting product exhibits clear and sharp tin-plated boundaries (tolerance ±0.1mm) with no plating burrs. The nickel-tin plating layer demonstrates excellent adhesion (without peeling after thermal shock and bending tests), and the tin layer is bright and dense, with salt spray resistance exceeding industry standards.

[0077] The method provided in this embodiment:

[0078] 1. Achieves high precision and high efficiency in flexible compatibility between local and overall electroplating: By integrating a local tin plating line with a precision mask, it is possible to flexibly choose to produce local or full-plated products on the same production line, which meets the diverse functional requirements of modern electronic components, saves precious metal consumables, and reduces subsequent processing steps.

[0079] 2. Significantly improves the adhesion and overall quality of the coating: The combination of "three-stage deep degreasing and activation" and "multi-stage gradient nickel electroplating" processes provides a near-ideal substrate for the coating (especially the localized plating areas), ensuring extremely strong adhesion within the nickel layer and between the nickel and tin layers, effectively avoiding defects such as peeling and blistering.

[0080] 3. Optimized plating performance: The "high-temperature nickel" process improves the reliability of the nickel substrate in high-temperature environments; the combined post-treatment of "ultrasonic hot water washing" and "high-temperature sealing" greatly enhances the cleanliness, corrosion resistance and anti-discoloration ability of the tin plating layer, resulting in good stability of the product during long-term storage and use.

[0081] 4. Enhanced process stability and contamination control: The reasonable process design, multi-stage countercurrent water washing and independent plating tank management effectively control cross-contamination between different plating solutions (such as nickel and tin), reduce production and maintenance costs, and improve the consistency of product yield.

[0082] 5. Suitable for automated continuous production: The entire process is coherent, easy to achieve fully automated control, has high production efficiency, and is suitable for large-scale industrial applications.

[0083] Figure 2 This is a schematic diagram of the structure of a continuous selective electroplating system provided in an embodiment of this application, as shown below. Figure 2As shown, the continuous selective electroplating system 200 of this embodiment includes: a three-stage deep degreasing and activation module 201, a multi-stage gradient nickel electroplating treatment module 202, a selective tin plating module 203, a high-efficiency post-treatment and sealing module 204, and an automated conveying control module 205.

[0084] The production line is sequentially equipped with a three-stage deep degreasing and activation module 201, a multi-stage gradient nickel electroplating module 202, a selective tin plating module 203, a high-efficiency post-treatment and sealing module 204, and an automated conveying control module 205.

[0085] The three-stage deep degreasing and activation module 201 includes an ultrasonic degreasing tank, a cathode electrolytic degreasing tank, an anodic electrolytic degreasing tank, a first water washing tank group, an electrolytic activation tank, a chemical activation tank, and a second water washing tank group; the three-stage deep degreasing and activation module 201 is used to perform three-stage deep degreasing and activation on the workpiece.

[0086] The multi-level gradient nickel electroplating module 202 includes a pre-plating nickel tank, a correction nickel tank, a nickel plating tank, a high-temperature nickel tank, a third water washing tank group, and a pre-plating acid activation tank; the multi-level gradient nickel electroplating module 202 is used to perform multi-level gradient nickel electroplating on the workpiece.

[0087] The selective tin plating module 203 includes a first tin plating line (a partial tin plating tank integrating a precision mask alignment device) and a second tin plating line (a full tin plating tank) arranged in parallel, as well as a switching mechanism for guiding the workpiece to one of the lines; the selective tin plating module 203 is used to perform selective tin plating on the workpiece.

[0088] The high-efficiency post-processing and sealing module 204 includes a neutralization tank, an ultrasonic hot water washing tank, a sealing tank, a fourth water washing tank group, and a drying device; the high-efficiency post-processing and sealing module 204 is used to perform high-efficiency post-processing and sealing operations on the workpiece.

[0089] The automated conveying control module 205 is used to convey the workpiece throughout the entire line, as well as the power supply, filtration, heating, control and detection units corresponding to each process tank.

[0090] Optionally, the first tin plating line includes a precision mask alignment device for masking and electroplating specific areas on the front and back of the workpiece.

[0091] Optionally, each tank of the multi-level gradient nickel electroplating module 202 is equipped with an independent temperature control, filtration, stirring and power supply system.

[0092] The system in this embodiment is used to execute the method in the above embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

Claims

1. A continuous selective electroplating method for nickel-tin, characterized in that, Includes the following steps: Step 1: Three-stage deep degreasing and activation treatment; Step 2: Multi-level gradient nickel plating treatment; Step 3: Selective tin plating; Step 4: Efficient post-processing and sealing; The selective tin plating process includes the step of selectively electroplating the front and back sides of the workpiece using a mask device.

2. The method according to claim 1, characterized in that, The sequence of the three-stage deep degreasing and activation treatment is as follows: Ultrasonic degreasing → cathodic electrolytic degreasing → anodic electrolytic degreasing → two-stage water washing → electrolytic activation → chemical activation → two-stage water washing.

3. The method according to claim 2, characterized in that, The sequence of the multi-level gradient nickel electroplating process is as follows: Pre-plating nickel → Nickel correction → Nickel plating → High-temperature nickel → Three-stage countercurrent water washing; The high-temperature nickel is processed at a temperature of 60-70°C.

4. The method according to claim 3, characterized in that, The efficient post-processing and sealing include: Neutralization → Ultrasonic hot water washing → Sealing → Water washing → Drying; The temperature of the ultrasonic hot water wash is 60-80℃, and the temperature of the sealing is 80-90℃.

5. The method according to claim 4, characterized in that, The selective tin plating process includes: The selective tin plating process is configured with a parallel and switchable first tin plating line and a second tin plating line. The first tin plating line performs localized selective electroplating; The second tin plating line performs overall full-surface electroplating.

6. A continuous selective electroplating system for implementing the method according to any one of claims 1-5, characterized in that, include: The production line is sequentially equipped with a three-stage deep degreasing and activation module, a multi-stage gradient nickel electroplating module, a selective tin plating module, a high-efficiency post-treatment and sealing module, and an automated conveying control module. The three-stage deep degreasing and activation module includes an ultrasonic degreasing tank, a cathode electrolytic degreasing tank, an anodic electrolytic degreasing tank, a first water washing tank group, an electrolytic activation tank, a chemical activation tank, and a second water washing tank group; the three-stage deep degreasing and activation module is used to perform three-stage deep degreasing and activation on the workpiece. The multi-level gradient nickel electroplating module includes a pre-plating nickel tank, a correcting nickel tank, a nickel plating tank, a high-temperature nickel tank, a third water washing tank group, and a pre-plating acid activation tank; the multi-level gradient nickel electroplating module is used to perform multi-level gradient nickel electroplating on the workpiece. The selective tin plating module includes a first tin plating line (a partial tin plating tank integrating a precision mask alignment device) and a second tin plating line (a full tin plating tank) arranged in parallel, as well as a switching mechanism for guiding the workpiece to one of the lines; the selective tin plating module is used to perform selective tin plating operations on the workpiece. The high-efficiency post-processing and sealing module includes a neutralization tank, an ultrasonic hot water washing tank, a sealing tank, a fourth water washing tank group, and a drying device; the high-efficiency post-processing and sealing module is used to perform high-efficiency post-processing and sealing operations on the workpiece. The automated conveying control module is used to transport the workpiece throughout the entire line, as well as the power supply, filtration, heating, control and detection units corresponding to each process tank.

7. The system according to claim 6, characterized in that, The first tin plating line includes a precision mask alignment device for masking and electroplating specific areas on the front and back of the workpiece.

8. The system according to claim 6, characterized in that, Each tank in the multi-level gradient nickel electroplating module is equipped with an independent temperature control, filtration, stirring, and power supply system.

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