Nickel plating solution and preparation method and application thereof

Abstract

The invention discloses a nickel plating solution which comprises the following preparation raw materials: a UPC nickel concentrated solution, boric acid, a UPC Ni RTR MU 01 cylinder opening agent, a UPC Ni RTR additive and an optional UPC Ni RTR brightener. Wherein the UPC nickel concentrated solution comprises nickel aminosulfonate; the preparation raw materials of the UPC Ni RTR MU 01 cylinder opening agent comprise a conductive agent and an ion activating agent; the UPC Ni RTR additive is prepared from the following raw materials: a grain refiner, a corrosion inhibitor, a stress relieving agent and a dispersing agent; the conductive agent comprises monopotassium phosphate and / or sodium dihydrogen phosphate; the ion activator comprises choline chloride; the grain refiner comprises nano silicon dioxide; the corrosion inhibitor comprises soluble cerium salt and / or soluble yttrium salt; and the UPC Ni RTR brightener comprises sodium vinyl sulfonate. A nickel plating layer obtained by deposition of the nickel plating solution provided by the invention is extremely low in stress and uniform in thickness distribution, and has excellent corrosion resistance and extremely excellent conductivity.

Description

Technical Field

[0001] This invention belongs to the field of nickel plating technology, specifically relating to a nickel plating solution and its preparation and application. Background Technology

[0002] Semiconductor nickel plating is a widely used metal plating process in the semiconductor industry. It involves depositing a thin layer of nickel on the surface of semiconductor devices through an electrochemical reaction to provide protection, connectivity, and improved electronic performance. The process typically involves using an electrolyte containing nickel ions (such as nickel sulfamate solution) as the plating bath. An external current is applied to reduce the nickel ions in the bath to metallic nickel, which is then deposited on the surface of the semiconductor device.

[0003] Although semiconductor electroplating nickel technology has broad application prospects and many advantages, there are still some challenges and shortcomings in practical applications. For example, with the rapid development of the semiconductor industry, the requirements for high quality, high efficiency and reliability are constantly increasing. The current nickel plating layer is difficult to meet the requirements in terms of uniformity and corrosion resistance. In addition, the technology also faces certain environmental protection and high wastewater treatment costs. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a nickel plating solution. The nickel plating layer deposited by the nickel plating solution of the present invention has extremely low stress, uniform thickness distribution, and excellent corrosion resistance and excellent conductivity, and can be widely used in IGBT devices, terminals, lead frames, semiconductor products, and military products.

[0005] The present invention also proposes a method for preparing the above-mentioned nickel plating solution.

[0006] The present invention also proposes a nickel plating method.

[0007] The present invention also proposes a nickel-plated part.

[0008] The present invention also proposes the application of the above-mentioned nickel-plated parts in the electronics industry.

[0009] According to a first aspect of the invention, a nickel plating bath is provided, comprising the following raw materials: UPC nickel concentrate, boric acid, UPC Ni RTR MU 01 starter, UPC Ni RTR additive, and optionally UPC Ni RTR brightener.

[0010] The UPC nickel concentrate includes nickel aminosulfonate;

[0011] The raw materials for preparing the UPC Ni RTR MU 01 starter include conductive agents and ion activators;

[0012] The raw materials for preparing the UPC Ni RTR additive include grain refiners, corrosion inhibitors, stress relievers, and dispersants.

[0013] The conductive agent includes potassium dihydrogen phosphate and / or sodium dihydrogen phosphate;

[0014] The ion activator includes choline chloride;

[0015] The grain refiner includes nano-silica;

[0016] The corrosion inhibitor includes soluble cerium salts and / or soluble yttrium salts;

[0017] The UPC Ni RTR brightener includes sodium vinyl sulfonate.

[0018] According to a first aspect of the present invention, at least the following beneficial effects are achieved:

[0019] The nickel plating solution of this invention is based on nickel sulfamate, providing a source of nickel metal ions. UPC Ni RTR MU 01, the plating bath starter, provides the electrolyte conductivity required for basic plating bath setup and enhances the activation effect through the adsorption effect of quaternary ammonium cations, improving the plating uniformity and reducing defects such as high-current scorching and blackening. Simultaneously, the conductivity agent of this invention can form a pH gradient buffer system with boric acid, maintaining it within a suitable range and preventing the pH of the plating solution from being too high or too low, which could affect the stability of the nickel solution and reduce the effect of high-current scorching. Furthermore, this invention also adds UPC Ni RTR additives and optionally UPC Ni RTR brighteners. UPC Ni RTR brighteners help control the brightness and leveling of the plating layer in low-temperature areas. In the UPC Ni RTR additive, nano-silica acts as a grain refiner, simultaneously refining grains and filling pores to form a denser coating structure, reducing roughness and improving hardness and wear resistance. Combined with rare earth corrosion inhibitors, it forms a Ce / YO-Ni composite oxide film to enhance corrosion resistance, while stress relievers synergistically improve ductility. This helps reduce coating stress, minimizing cracking, peeling, and its impact on adhesion to the substrate, while also providing good alignment, ensuring coating quality and uniformity.

[0020] By adopting the above technical solution, the nickel plating solution provided by the present invention has good conductivity and dispersion ability, excellent low current density coverage ability and excellent thickness distribution ability; the formed coating has extremely low stress, high hardness, strong adhesion, dense and glossy, uniform thickness distribution, and excellent corrosion resistance and excellent conductivity.

[0021] In some embodiments of the present invention, the grain refiner is mesoporous nano-silica with a particle size of 5-30 nm, which can be about 10 nm, about 15 nm, about 20 nm, or about 25 nm; preferably 10-20 nm.

[0022] In some embodiments of the present invention, the grain refiner is prepared by the sol-gel method.

[0023] In some embodiments of the present invention, the corrosion inhibitor comprises cerium nitrate and / or yttrium nitrate.

[0024] In some embodiments of the present invention, the stress reliever includes sodium saccharin and / or 2-mercaptobenzimidazole (MBI).

[0025] In some embodiments of the present invention, the dispersant includes, but is not limited to, polyoxyethylene lauryl ether. The dispersant of the present invention can simultaneously perform wetting and dispersing functions, reduce pinholes and bubbles, and help eliminate edge effects.

[0026] In some embodiments of the present invention, the nickel plating solution comprises the following raw materials at the following concentrations: 100-400 mL / L of UPC nickel concentrate, 30-50 g / L of boric acid, 200-550 mL / L of Ni RTR MU 01 plating starter, 15-40 mL / L of UPC Ni RTR additive, and optionally 1-5 mL / L of UPC Ni RTR brightener.

[0027] In some embodiments of the present invention, the concentration of the UPC nickel concentrate can be about 100 mL / L, about 150 mL / L, about 200 mL / L, about 250 mL / L, about 300 mL / L, about 350 mL / L or about 400 mL / L; preferably 200-300 mL / L.

[0028] In some embodiments of the present invention, each 10 mL / L UPC nickel concentrate provides a nickel metal ion concentration of 1.5-2.0 g / L, for example, about 1.8 g / L. Conventional nickel plating solutions typically require nickel concentrations as high as 90 g / L or more, while the nickel plating solution of the present invention uses a relatively low nickel ion concentration, which reduces carryover, saves energy and emissions, and reduces operating costs.

[0029] In some embodiments of the present invention, the concentration of boric acid may be about 30 g / L, about 35 g / L, about 40 g / L, about 45 g / L or about 50 g / L; preferably about 35-45 g / L.

[0030] In some embodiments of the present invention, the concentration of Ni RTR MU 01 starter can be about 200 mL / L, about 250 mL / L, about 300 mL / L, about 350 mL / L, about 400 mL / L, about 450 mL / L, about 500 mL / L, or about 550 mL / L; preferably 250-450 mL / L.

[0031] In some embodiments of the present invention, the UPC Ni RTR MU 01 starter agent comprises the following raw materials at the following concentrations: 30-35 g / L conductive agent and 20-25 g / L ion activator.

[0032] When the concentration of UPC Ni RTR MU 01 plating starter is insufficient, the plating uniformity of the plating bath will decrease, and the nickel plating layer in high current density areas is prone to scorching. When the concentration is excessive, the plating layer is prone to blackening. Precise control of anodic activation can also be achieved through titration.

[0033] In some embodiments of the present invention, the concentration of the UPC Ni RTR additive may be about 15 mL / L, about 20 mL / L, about 25 mL / L, about 30 mL / L, about 35 mL / L, or about 40 mL / L; preferably 15-30 mL / L.

[0034] In some embodiments of the present invention, the UPC Ni RTR additive comprises the following raw materials at the following concentrations: 10-15 g / L grain refiner, 20-25 g / L corrosion inhibitor, 85-90 g / L stress reliever, and 35-40 g / L dispersant.

[0035] When the concentration of grain refiner is insufficient, the gloss of the coating will decrease.

[0036] In some embodiments of the present invention, the nickel plating solution does not contain UPC Ni RTR brightener.

[0037] In some embodiments of the present invention, the concentration of the UPC Ni RTR brightener is 1-3 mL / L, for example, about 2 mL / L.

[0038] In some embodiments of the present invention, the UPC Ni RTR brightener is 40-50% by mass, for example, about 45% sodium vinyl sulfonate.

[0039] In some embodiments of the present invention, the nickel plating solution further includes water, preferably pure water and / or deionized water.

[0040] The nickel plating solution of this invention uses nickel sulfamate as the main salt. The main salt system is stabilized by the adsorption of choline cations. The pH is precisely controlled by the borate-dihydrogen phosphate ion gradient buffer. The nano-silica refinement and rare earth salt interface passivation form a dense Ce / YO-Ni composite oxide film. With the help of low stress and wettability and dispersion regulation, the high hardness, corrosion resistance and deposition efficiency of the coating are improved simultaneously. Moreover, the plating solution has good long-term stability (no precipitation for 6 months), which is significantly better than the traditional nickel plating solution system.

[0041] According to a second aspect of the present invention, a method for preparing the above-mentioned nickel plating solution is provided, comprising the following steps:

[0042] The UPC nickel concentrate, boric acid, UPC Ni RTR MU 01 starter, UPC Ni RTR additive and optional UPC Ni RTR brightener are mixed to obtain a mixture.

[0043] The pH of the mixture is adjusted to 3.0-4.6 and aged to obtain the nickel plating solution.

[0044] According to a second aspect of the present invention, at least the following beneficial effects are achieved:

[0045] The method for preparing the nickel plating solution of this invention is simple to operate, safe, efficient, and easy to apply on a large scale.

[0046] In some embodiments of the present invention, the pH of the mixture can be adjusted to 3.0, 3.5, 4.0 or 4.6.

[0047] By employing the above-described technical solution, this invention adjusts the pH value of the nickel plating solution to the aforementioned range, thereby improving the stability of the solution, reducing the precipitation of impurities and sediments, and enhancing film-forming properties, resulting in a more uniform and stable coating. Excessively high pH leads to increased coating brittleness, while excessively low pH results in severe hydrogen evolution at the cathode, making coating formation difficult.

[0048] In some embodiments of the present invention, pH is measured and adjusted at a temperature above 55°C; preferably, pH is measured and adjusted at the electroplating operating temperature.

[0049] In some embodiments of the present invention, nickel carbonate and / or aminosulfonic acid are used as pH adjusters to achieve stable, slow, and precise pH adjustment without interfering with other components of the nickel plating solution, thereby ensuring the quality of the plating layer.

[0050] In practice, when the pH of the nickel plating solution is low, basic nickel carbonate can be added to raise the pH of the solution; when the pH of the nickel plating solution is high, aminosulfonic acid can be added to lower the pH of the solution.

[0051] In some embodiments of the present invention, basic nickel carbonate should not be added directly to the plating bath, but should be wrapped in a filter bag and placed in a filter press to dissolve. This is because basic nickel carbonate has poor water solubility and may produce precipitation, forming particulate matter, which has an adverse effect on the plating quality.

[0052] In some embodiments of the present invention, water of about 15%-30% of its total volume is heated to 50-60°C (e.g., 55°C) before other materials are added.

[0053] In some embodiments of the present invention, boric acid is first mixed into a paste with a small amount of hot water (e.g., hot water at 50-60°C), and then the boric acid is slowly added.

[0054] In some embodiments of the present invention, the preparation of the UPC Ni RTR MU 01 starter agent includes the following steps:

[0055] Dissolve the conductive agent and ion activator in water to obtain the UPC Ni RTR MU 01 starter.

[0056] In some embodiments of the present invention, the preparation of the UPC Ni RTR additive includes the following steps:

[0057] The grain refiner is pre-dispersed by mixing with a dispersant (e.g., by ultrasound and high-speed shearing), and then a corrosion inhibitor and stress reliever are added to form a stable suspension system.

[0058] In some embodiments of the present invention, the aging temperature is 45-55°C, for example, about 50°C.

[0059] In some embodiments of the present invention, the aging time is 24-40 hours, for example, about 24 hours, about 28 hours, about 32 hours, about 36 hours, or about 40 hours.

[0060] According to a third aspect of the present invention, a nickel plating method using the above-described nickel plating solution is provided, comprising electroplating nickel with the above-described nickel plating solution.

[0061] According to a third aspect of the present invention, at least the following beneficial effects are achieved:

[0062] The nickel plating method provided by this invention delivers a coating superior to those obtained in traditional electroplating nickel processes. The resulting coating exhibits extremely low stress, uniform thickness distribution, excellent corrosion resistance, and exceptional electrical conductivity. Furthermore, the nickel plating method provided by this invention offers a wide range of applicable current densities, effectively increasing production capacity, reducing wastewater treatment costs, and providing greater reliability and process lifespan.

[0063] In some embodiments of the present invention, the nickel plating method includes the following steps:

[0064] S1. Pretreatment of the workpiece to be plated: The workpiece to be plated is subjected to the following steps: immersion degreasing, water washing (1-3 times), cathode electrolysis degreasing, anodic electrolysis degreasing, water washing (1-3 times), pickling (1-3 times), and water washing (1-3 times) to obtain the pretreated workpiece.

[0065] S2. Electroplating: The pre-treated parts are immersed in an electroplating solution for electroplating to obtain nickel-plated parts.

[0066] In some embodiments of the present invention, the current density of the electroplating is 2-30 ASD (Amperes per square decimeter, A / dm). 2 For example, the current density can be about 2 ASD, about 4 ASD, about 6 ASD, about 8 ASD, about 10 ASD, 15 ASD, about 20 ASD, about 25 ASD, or about 30 ASD. Preferably, the current density is 3-20 ASD.

[0067] In some embodiments of the present invention, the electroplating temperature is 55-68°C; for example, the electroplating temperature can be about 55°C, about 60°C, about 65°C or about 68°C.

[0068] In some embodiments of the present invention, the electroplating time is 1-10 minutes, for example, about 5 minutes.

[0069] In some embodiments of the present invention, the nickel metal ions in the nickel plating solution originate from the dissolution of the nickel anode and / or the addition of nickel sulfamate concentrate.

[0070] In some embodiments of the present invention, the concentration of the nickel metal ions is maintained at 20-60 g / L; for example, at about 20 g / L, about 25 g / L, about 30 g / L, about 35 g / L, about 40 g / L, about 50 g / L, about 55 g / L, or about 60 g / L; preferably 30-50 g / L.

[0071] According to some embodiments of the present invention, the nickel plating method can be a roll-to-roll (RTR) surface treatment process, which is superior to conventional electroplating nickel processes. Therefore, it is applicable to continuous surface treatment, particularly for flexible materials, to improve the surface properties of the substrate and enhance its conductivity, corrosion resistance, and mechanical strength.

[0072] According to a fourth aspect of the present invention, a nickel-plated part is provided, the nickel-plated part comprising a substrate and a nickel plating layer located on the surface of the substrate, the nickel plating layer being formed by the above-described nickel plating solution or prepared by the above-described nickel plating method.

[0073] According to a fourth aspect of the present invention, at least the following beneficial effects are achieved:

[0074] The nickel-plated parts provided by this invention have a diamond nickel plating layer. Due to the extremely low stress and uniform thickness distribution of the plating layer, as well as its excellent corrosion resistance and excellent conductivity, it has broad application prospects and is particularly suitable for IGBT devices, terminals, lead frames, semiconductor products and military products.

[0075] In some embodiments of the present invention, the thickness of the nickel plating layer is 0.5-50 μm, for example, about 1 μm, about 5 μm, about 10 μm, about 20 μm, about 30 μm or about 50 μm.

[0076] In some embodiments of the present invention, the component includes at least one of an IGBT device, a terminal, or a lead frame.

[0077] According to a fifth aspect of the present invention, the application of the above-described nickel-plated parts in the electronics industry is proposed.

[0078] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0079] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the same parameter value is the same in all embodiments. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0080] In the description of this invention, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0081] Unless otherwise stated herein, the numerical ranges described herein are intended only as a shorthand for individually referring to each individual value falling within the range, and each individual value is incorporated into the specification as if it were described separately herein. Unless otherwise stated, all precise values ​​provided herein represent corresponding approximations (e.g., all precise exemplary values ​​provided with respect to a particular factor or measurement may be considered as providing corresponding approximate measurements, modified with "about" where appropriate).

[0082] As used herein, when used in conjunction with numerical values, the term "about" means a set or range of values. For example, "about" means a range of values ​​that includes ±5%, ±2%, ±1%, ±0.5%, ±0.2%, or ±0.1% of that value. In one embodiment, the term "about" refers to a range of values ​​that are 5% more or less than a specific value. In another embodiment, the term "about" refers to a range of values ​​that are 2% more or less than a specific value. In yet another embodiment, the term "about" refers to a range of values ​​that are 1% more or less than a specific value.

[0083] Example 1

[0084] This embodiment provides a nickel plating solution comprising the following raw materials at the following concentrations: 230 mL / L UPC nickel concentrate, 40 g / L boric acid, 400 mL / L Ni RTR MU 01 plating starter, 20 mL / L UPC Ni RTR additive, and 1.2 mL / L UPC Ni RTR brightener;

[0085] UPC nickel concentrate is a nickel sulfamate concentrate, providing a nickel metal ion concentration of 1.8 g / L per 10 mL / L;

[0086] Preparation of UPC Ni RTR MU 01: Dissolve potassium dihydrogen phosphate and choline chloride in pure water according to the stoichiometric ratio of 35 g / L potassium dihydrogen phosphate and 22 g / L choline chloride.

[0087] Preparation of UPC Ni RTR additive: Mesoporous silica and polyoxyethylene lauryl ether were pre-dispersed (ultrasonication 40kHz×30min+high-speed shearing 12000rpm×10min) according to the stoichiometric ratio of 15g / L mesoporous nano silica (20nm), 23g / L cerium nitrate, 90g / L sodium saccharin and 40g / L polyoxyethylene lauryl ether. Then, cerium nitrate and sodium saccharin were added to form a stable suspension system.

[0088] The UPC Ni RTR brightener is sodium vinyl sulfonate with a mass concentration of 40%.

[0089] According to the raw material ratio provided above, add approximately 20% of the total volume of pure water to the tank and heat it to 55°C; add several EU portions of UPC Ni nickel concentrate and stir until homogeneous; add the required amount of boric acid (pre-mixed with a small amount of hot water to form a paste) and stir until completely dissolved; add the required amount of UPC Ni RTR Mu 01 plating starter and stir; add the required amount of UPC Ni RTR additive and stir until homogeneous; then add the required amount of UPC Ni RTR brightener and stir until homogeneous; then add the remaining pure water to adjust to the operating water level, raise the temperature of the mixture to the operating range of 65°C, and adjust the pH value to 3.5. Then, place the above mixture at a constant temperature of 50°C for 36 hours to form a transparent solution, which is the nickel plating solution.

[0090] Example 2

[0091] This embodiment provides a nickel plating solution, which differs from Embodiment 1 only in that the nickel plating solution includes the following raw materials at the following concentrations: 230 mL / L UPC nickel concentrate, 40 g / L boric acid, 400 mL / L Ni RTR MU 01 plating starter and 20 mL / L UPC Ni RTR additive.

[0092] UPC Ni RTR MU 01 starter contains the following raw materials at the following concentrations: 32 g / L potassium dihydrogen phosphate and 24 g / L choline chloride;

[0093] UPC Ni RTR additives include the following raw materials at the following concentrations: 17 g / L mesoporous nano silica, 23 g / L cerium nitrate, 90 g / L sodium saccharin, and 40 g / L polyoxyethylene lauryl ether.

[0094] Example 3

[0095] This embodiment provides a nickel plating solution, which differs from Example 1 only in that: the nickel plating solution includes the following raw materials at the following concentrations: 230 mL / L UPC nickel concentrate, 40 g / L boric acid, 400 mL / L Ni RTR MU 01 plating starter, 20 mL / L UPC Ni RTR additive, and 1.8 mL / L UPC Ni RTR brightener;

[0096] UPC Ni RTR MU 01 starter contains the following raw materials at the following concentrations: 35 g / L potassium dihydrogen phosphate and 22 g / L choline chloride;

[0097] UPC Ni RTR additives include the following raw materials at the following concentrations: 12 g / L mesoporous nano silica, 25 g / L cerium nitrate, 90 g / L sodium saccharin and 40 g / L polyoxyethylene lauryl ether.

[0098] The UPC Ni RTR brightener is sodium vinyl sulfonate with a mass concentration of 40%.

[0099] Example 4

[0100] This embodiment provides a nickel plating solution, which differs from Example 1 only in that the nickel plating solution includes the following raw materials at the following concentrations: 230 mL / L UPC nickel concentrate, 40 g / L boric acid, 400 mL / L Ni RTR MU 01 plating starter, 30 mL / L UPC Ni RTR additive, and 1.2 mL / L UPC Ni RTR brightener;

[0101] UPC Ni RTR MU 01 starter contains the following raw materials at the following concentrations: 35 g / L potassium dihydrogen phosphate and 22 g / L choline chloride;

[0102] UPC Ni RTR additives include the following raw materials at the following concentrations: 15 g / L mesoporous nano silica, 23 g / L cerium nitrate, 90 g / L sodium saccharin and 40 g / L polyoxyethylene lauryl ether.

[0103] The UPC Ni RTR brightener is sodium vinyl sulfonate with a mass concentration of 40%.

[0104] Example 5

[0105] This embodiment provides a nickel plating solution, which differs from Example 1 only in that the prepared mixture is then aged at a constant temperature of 52°C for 30 hours.

[0106] Comparative Example 1

[0107] This comparative example provides a nickel plating solution, which differs from Example 1 only in that thiourea is used instead of mesoporous nano-silica, while the other conditions are the same.

[0108] Comparative Example 2

[0109] This comparative example provides a nickel plating solution that differs from Example 1 only in that benzotriazole (BTA) is used instead of cerium nitrate, while all other conditions remain the same.

[0110] Comparative Example 3

[0111] This comparative example provides a nickel plating solution. The only difference between this comparative example and Example 1 is that sodium sulfate is used instead of potassium dihydrogen phosphate, while the other conditions are the same.

[0112] Test case

[0113] The nickel plating solutions provided in the above embodiments and comparative examples were used to electroplate nickel, and then the performance parameters of the nickel plating layer were tested.

[0114] The specific nickel plating process is as follows:

[0115] S1. The workpiece to be plated is pretreated by sequentially undergoing the following steps: immersion degreasing, secondary water rinsing, cathode electrolytic degreasing, anodic electrolytic degreasing, secondary water rinsing, secondary acid pickling, and secondary water rinsing.

[0116] S2. The pretreated workpiece is suspended in a Hastelloy bath containing nickel plating solution (the nickel plating solution prepared in the examples and comparative examples) for nickel plating, depositing nickel ions onto the surface of the workpiece to form a uniform coating. The process conditions are as follows: the anode is a nickel angle, the immersion depth of the workpiece in the plating solution is 5 cm, and the distance between the workpiece and the pure nickel anode plate is 5 cm; the temperature of the nickel plating solution is 65°C, the current density is 10 ASD, the electroplating deposition rate is 2.5 μm / min, and the time is 5 min.

[0117] S3. After the plating is deposited, remove the plated parts from the plating tank and clean them to remove any residual nickel plating solution from the surface.

[0118] S4. After cleaning, place the plated parts in an oven to dry and remove surface moisture;

[0119] S5. Polish and grind the coating to obtain nickel-plated parts.

[0120] The parts to be plated are:

[0121] This test example performs relevant performance tests on the nickel-plated part obtained in step S6. The test method is as follows:

[0122] (1) Coating appearance inspection: The appearance and coverage of the coating are determined by visual inspection. If the coating is bright, smooth and fine, and there are no defects such as pinholes, pits, bubbles, or haze on the surface, it is considered qualified; otherwise, it is considered unqualified.

[0123] (2) Adhesion test: According to the STM D3359 cross-cut test, observe whether there is peeling, peeling or falling off.

[0124] (3) Microhardness test: The coating was tested using an HVS-1000A digital display microhardness tester with a load of 100g and an application time of 20s.

[0125] The test results are shown in Table 1.

[0126] Table 1. Performance Testing

[0127]

[0128] The nickel plating layer prepared by this invention has a smooth and bright appearance, a uniform and delicate surface, uniform thickness, high hardness, and good adhesion and corrosion resistance. In contrast, the nickel plating layer prepared in Comparative Example 1 has significantly reduced hardness, and the TOC increases due to the introduction of an organic passivating agent; Comparative Example 2 lacks a rare earth-nano synergistic strengthening mechanism, resulting in decreased adhesion (a small amount of edge detachment) and corrosion resistance; Comparative Example 3 suffers from decreased thickness uniformity due to reduced current distribution uniformity, surface defects, and significantly reduced hardness and adhesion (edge ​​detachment), thus leading to decreased corrosion resistance.

[0129] In summary, the nickel plating solution of the present invention has good stability and excellent thickness distribution capability, and can prepare nickel-plated parts with extremely low stress, high adhesion, high hardness, excellent corrosion resistance and excellent conductivity. Moreover, the nickel-plated parts prepared have a smooth and bright appearance, and a uniform and delicate surface, which has considerable application potential.

[0130] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A nickel plating solution, characterized in that, The preparation materials include the following: UPC nickel concentrate, boric acid, UPC Ni RTR MU01 starter, UPC Ni RTR additives and optional UPC Ni RTR brightener; The UPC nickel concentrate includes nickel aminosulfonate; The raw materials for preparing the UPC Ni RTR MU 01 starter include conductive agents and ion activators; The raw materials for preparing the UPC Ni RTR additive include grain refiners, corrosion inhibitors, stress relievers, and dispersants. The conductive agent includes potassium dihydrogen phosphate and / or sodium dihydrogen phosphate; The ion activator includes choline chloride; The grain refiner includes nano-silica; The corrosion inhibitor includes soluble cerium salts and / or soluble yttrium salts; The UPC Ni RTR brightener includes sodium vinyl sulfonate.

2. The nickel plating solution according to claim 1, characterized in that, Each 10 mL / L of the UPC nickel concentrate provides a concentration of 1.5-2.0 g / L of nickel metal ions; The grain refiner is mesoporous nano-silica with a particle size of 5-30 nm. The corrosion inhibitor includes cerium nitrate and / or yttrium nitrate; The stress reliever includes sodium saccharin and / or 2-mercaptobenzimidazole; The dispersant includes polyoxyethylene lauryl ether.

3. The nickel plating solution according to claim 1 or 2, characterized in that, The nickel plating solution comprises the following raw materials at the following concentrations: 100-400 mL / L of UPC nickel concentrate, 30-50 g / L of boric acid, 200-550 mL / L of Ni RTR MU 01 plating starter, 15-40 mL / L of UPC NiRTR additive, and optional 1-5 mL / L of UPC Ni RTR brightener. The UPC Ni RTR MU 01 starter agent comprises the following raw materials at the following concentrations: 30-35 g / L conductive agent and 20-25 g / L ion activator; The UPC Ni RTR additive comprises the following raw materials at the following concentrations: 10-15 g / L grain refiner, 20-25 g / L corrosion inhibitor, 85-90 g / L stress reliever, and 35-40 g / L dispersant. The UPC Ni RTR brightener comprises sodium vinyl sulfonate at a mass concentration of 40-50%.

4. The method for preparing the nickel plating solution according to any one of claims 1 to 3, characterized in that, Includes the following steps: The UPC nickel concentrate, boric acid, UPC Ni RTR MU 01 starter, UPC Ni RTR additive and optional UPC Ni RTR brightener are mixed to obtain a mixture. The pH of the mixture is adjusted to 3.0-4.6 and aged to obtain the nickel plating solution.

5. The preparation method according to claim 4, characterized in that, The preparation of the UPC Ni RTR additive includes the following steps: The grain refiner and dispersant are mixed and pre-dispersed, and then the corrosion inhibitor and stress reliever are added to form a suspension system; And / or, the pH adjustment uses nickel carbonate and / or aminosulfonic acid as pH adjusters; And / or, the aging temperature is 45-55℃; the aging time is 24-40h.

6. A method for nickel plating, characterized in that, This includes electroplating nickel using the nickel plating solution described in any one of claims 1 to 3.

7. The nickel plating method according to claim 6, characterized in that, The current density for electroplating is 2-30 ASD; And / or, the electroplating temperature is 55-68℃; the electroplating time is 1-10 min; And / or, to maintain the concentration of the nickel metal ions at 20-60 g / L.

8. A nickel-plated part, characterized in that, The nickel-plated part includes a substrate and a nickel plating layer located on the surface of the substrate, the nickel plating layer being formed by the nickel plating solution of any one of claims 1 to 3 or prepared by the nickel plating method of any one of claims 6 to 7.

9. The nickel-plated part according to claim 8, characterized in that, The thickness of the nickel plating layer is 0.5-50 μm; And / or, the substrate includes at least one of an IGBT device, a terminal, or a lead frame.

10. The application of the nickel-plated parts as described in claim 8 or 9 in the electronics industry.

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