A high current copper plating additive and methods of use and applications thereof
This high-current copper plating additive, formed by a specific ratio of brightener and wetting agent, solves the problems of non-dense and uneven coatings in copper electroplating technology, achieving high-efficiency electroplating and low-cost production. It is suitable for various production lines and simplifies wastewater treatment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANTONG MACDERLUN MATERIAL LTD
- Filing Date
- 2024-12-30
- Publication Date
- 2026-05-22
AI Technical Summary
Existing copper electroplating technology faces problems such as poor plating quality, low production efficiency and high cost in the manufacture of high-density electronic interconnect materials. In particular, at the extreme nanoscale, the molecular behavior of electroplating solution additives changes, resulting in non-dense and uneven plating.
By employing a specific ratio of brighteners and wetting agents, including sodium polydithiopropane sulfonate, sodium N,N-dimethyldithioformamide propane sulfonate, 3-mercapto-1-propanesulfonic acid inner salt, and polyethylene glycol polyethers, a high-current copper plating additive is formed, which can operate stably under high current density, improving electroplating efficiency and coating quality.
It achieves bright, fine-grained coatings with low internal stress at high current densities, shortens electroplating time, improves production efficiency and reduces costs. It is suitable for roll plating, rack plating and barrel plating production lines, and wastewater treatment is simple.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of electroplating technology, and in particular to a high-current copper plating additive, its usage method, and its application. Background Technology
[0002] Copper electroplating, as one of the core processes in integrated circuit and PCB manufacturing, plays a crucial role in the performance and reliability of electronic products. However, traditional copper electroplating processes fall short when faced with the high demands of manufacturing high-density electronic interconnect materials. Especially today, with technology nodes shrinking and chip trench and linewidth dimensions entering the extreme nanoscale range, electroplating interconnect processes face even more stringent challenges. Within this confined nanoscale space, the diffusion and adsorption behavior of additive molecules in the electroplating solution changes, which is detrimental to obtaining a densely grown copper layer.
[0003] To address these issues, researchers have begun developing novel high-current copper plating additives. These additives need to operate stably at high current densities, improving electroplating efficiency while ensuring the quality and uniformity of the plating layer. The design and development of these additives not only consider the effects of individual components but also delve into the interaction mechanisms between them, including synergistic and antagonistic effects. Through rational formulation and proportioning, the goal is to achieve a bright, smooth plating layer with excellent in-hole electroplating results. Currently, the copper plating technology field generally suffers from low plating current densities and long plating times, which not only affect production efficiency but also increase energy consumption and production costs. With technological advancements and increasing industrial production demands, developing a high-current copper plating additive has become crucial to solving this problem.
[0004] Chinese patent application CN107177868A discloses a compound brightener for copper plating and its preparation method. The brightener includes sodium phenyl polydisulfide dipropane sulfonate, heterocyclic sulfides, polyether compounds, surfactants, and rare earth salts. The resulting copper plating layer is dense, bright, and uniform, with good adhesion to the substrate and no pinholes or pitting. Chinese patent application CN115341250A discloses a copper plating solution composition for filling through-holes in IDI boards, comprising a base solution, a leveling agent, a brightener, and a wetting agent. When using VCP (vertical continuous plating) to plate copper on blind-hole substrates of HDI boards, the plated board exhibits a high through-hole filling rate and high filling efficiency. However, these prior art technologies have not effectively solved the aforementioned technical problems.
[0005] In conclusion, developing a high-current copper plating additive is an important way to solve the problems existing in current copper plating technology, improve production efficiency, and reduce production costs. Summary of the Invention
[0006] Currently, the development of high-current copper plating additives on the market is quite challenging, mainly because many factors influence their application in electroplating processes. The final plating effect is affected by various factors, including the additive's molecular structure, stability in the electroplating solution, and its influence on copper ion transport and electrocrystallization. To address these issues, this invention develops an additive that achieves high-quality plating with shorter plating times and higher current densities, solving the aforementioned technical problems and promoting the further development of copper plating technology.
[0007] The first aspect of this invention provides a high-current copper plating additive, wherein the raw materials for preparing the copper plating additive include: 0.1-5 g / L of brightener, 5-60 g / L of wetting agent, and water as solvent.
[0008] Preferably, the raw materials for preparing the copper plating additive include: 0.5-2 g / L of brightener, 20-40 g / L of wetting agent, and water as solvent.
[0009] The brightener may be one or more combinations of sodium polydithiopropane sulfonate (SPS), sodium N,N-dimethyldithiopropane sulfonate (DPS), 3-mercapto-1-propanesulfonic acid inner salt (MPS), sodium polythiopropane sulfonate, 2-imidazolium thione, and 2-mercaptobenzimidazole.
[0010] Preferably, the brightener comprises one or more combinations of sodium polydithiopropane sulfonate, sodium N,N-dimethyldithiocarbamate propane sulfonate, and 3-mercapto-1-propanesulfonic acid inner salt.
[0011] More preferably, the brightener comprises sodium polydithiopropane sulfonate, sodium N,N-dimethyldithiocarbamate propane sulfonate, and 3-mercapto-1-propanesulfonic acid inner salt in a mass ratio of (1-3):(1-5):(1-7).
[0012] More preferably, the mass ratio of sodium polydisulfide dipropane sulfonate, sodium N,N-dimethyldithiocarbamate propane sulfonate, and the inner salt of 3-mercapto-1-propanesulfonic acid is 1:1:1, 2:3:5, or 3:5:7.
[0013] Preferably, the wetting agent comprises polyethylene glycol and polyether, wherein the mass ratio of polyethylene glycol to polyether is 1:(2.5-3).
[0014] Preferably, the polyethylene glycol includes one or more combinations of PEG-4000, PEG-8000, and PEG-10000.
[0015] Preferably, the polyether has a hydroxyl value of 270-290 mgKOH / g, a viscosity of 60-80 mPa·s, and a viscosity test temperature of 25℃.
[0016] More preferably, the polyether is a propylene glycol polyether.
[0017] This invention does not impose any particular limitation on the preparation method of the copper plating additive; any method commonly used in the art can be employed. For example, mixing the raw materials according to the formula amount yields the additive.
[0018] The preferred brighteners of this invention are sodium polydisulfide dipropane sulfonate, sodium N,N-dimethyldithioformamide propane sulfonate, and 3-mercapto-1-propanesulfonic acid inner salt in a mass ratio of (1-3):(1-5):(1-7). Simultaneously, the preferred wetting agent is a propylene glycol-based polyether, which enhances the effectiveness of the additives. The resulting copper plating additive can be used at high current densities, significantly improving electroplating efficiency. Furthermore, it further enhances the plating effect, resulting in a bright coating with fine crystals, low internal stress, and excellent ductility. This shortens the electroplating time while improving the quality of the finished product.
[0019] A second aspect of the present invention provides a method for using the high-current copper plating additive as described above, wherein the copper plating additive is used at a current density ≤ 50 A / dm³. 2 The copper plating additive of this invention can achieve a maximum current density of 50 A / dm² during use. 2 This can greatly broaden the upper limit of current density for copper plating, shorten the plating time, and significantly improve the efficiency of the plating process.
[0020] A third aspect of the present invention provides an application of the high-current copper plating additive as described above, wherein the copper plating additive is applied to any one of a roll plating production line, a rack plating production line, or a barrel plating production line.
[0021] Beneficial effects:
[0022] This invention provides a high-current copper plating additive and its application, which has the following advantages:
[0023] (1) The brightener in the copper plating additive of the present invention is preferably sodium polydisulfide dipropane sulfonate, sodium N,N-dimethyldithiocarbamate propane sulfonate, and 3-mercapto-1-propanesulfonic acid inner salt in a mass ratio of (1-3):(1-5):(1-7), which improves the effect of the additive and the copper plating additive can be used at high current density, and the electroplating efficiency is significantly improved.
[0024] (2) The wetting agent in the copper plating additive of the present invention preferably includes polyethylene glycol and polyether, and preferably the polyether is a propylene glycol polyether, which can further improve the plating effect. The final plating layer is bright, with fine crystals and low internal stress, and the plating layer has excellent ductility, which improves the quality of the parts while shortening the electroplating time.
[0025] (3) The copper plating additive provided by this invention can withstand high current density electroplating conditions, with a maximum current density of up to 50 A / dm² during use. 2 It has significant application advantages compared to existing products on the market.
[0026] (4) The copper plating additive provided by the present invention is particularly suitable for roll plating production lines, and can also be flexibly applied to rack plating production lines and barrel plating production lines according to actual needs, with a wide range of applications.
[0027] (5) The formulation system of the copper plating additive of the present invention is simple and does not contain dyes. The wastewater brought out by the copper tank after production is less likely to interfere with the subsequent processes. This not only helps to reduce the cost and time of wastewater treatment, but also ensures the smooth progress of the subsequent processes.
[0028] (6) The raw materials of this invention are readily available, the process is simple, and it can meet the requirements of large-scale mass production, with broad application prospects. Attached Figure Description
[0029] Figure 1 Schematic diagram of plated parts with through holes; 1 to 6 in the figure are sampling points. Detailed Implementation
[0030] All raw materials used in this invention are commercially available, as detailed below.
[0031] SPS: Sodium polydisulfide dipropane sulfonate, CAS No. 27206-35-5, sourced from Shanghai Pimsey Trading Co., Ltd.
[0032] DPS: Sodium N,N-dimethyldithiocarbamate propane sulfonate, CAS No. 2039-68-1.
[0033] MPS: 3-mercapto-1-propanesulfonic acid inner salt, specifically sodium 3-mercapto-1-propanesulfonic acid, CAS number 17636-10-1.
[0034] PEG-4000: This product is sourced from Dongda Chemical's Donol PEG 4000 sold by Chongqing Kaiyin Chemical Co., Ltd.
[0035] PEG-8000: This product is the PEG-8000 model sold by Shanghai Huijun Chemical Co., Ltd.
[0036] PEG-10000: This product is a PEG-10000 model sold by Shanghai Huijun Chemical Co., Ltd.
[0037] Propylene glycol polyethers: These are derived from the DL-400 model product sold by Tianjin Zhonghe Shengtai Chemical Co., Ltd.
[0038] Example
[0039] Examples 1-3 and Comparative Examples 1-2
[0040] A high-current copper plating additive, the formulation of which is shown in Table 1 below.
[0041] Table 1. Copper plating additive formulations for Examples 1-3 and Comparative Examples 1-2
[0042]
[0043] Note: The values in the table are concentrations, in g / L; the solvent for the additives is water.
[0044] In Example 1, the mass ratio of SPS, DPS, and MPS was 1:1:1, and the total amount of brightener added was 0.5 g / L.
[0045] In Example 2, the mass ratio of SPS, DPS, and MPS was 2:3:5, and the total amount of brightener added was 1.2 g / L.
[0046] In Example 3, the mass ratio of SPS, DPS, and MPS was 3:5:7, and the total amount of brightener added was 2 g / L.
[0047] In Comparative Example 1, the mass ratio of SPS, DPS, and MPS was 1:1:1, and the total amount of brightener added was 0.3 g / L.
[0048] In Comparative Example 2, the mass ratio of SPS, DPS, and MPS was 3:5:7, and the total amount of brightener added was 3 g / L.
[0049] The preparation method of the high-current copper plating additive is as follows: mix the raw materials according to the formula amount to obtain the additive.
[0050] Performance testing
[0051] The copper plating additives of Examples 1-3 and Comparative Examples 1-2 were added to the electroplating solution, and the deep plating capability of the coating was measured. The electroplating solution formulation, electroplating conditions, and depth capability test results are shown in Table 2 below.
[0052] Note: Throwing Power (TP) refers to the ratio of the copper plating thickness at the center of the hole to the copper plating thickness at the hole opening. An important indicator for evaluating the effectiveness of PCB through-hole plating is the uniformity of the copper plating thickness within the hole; a higher Throwing Power indicates better uniformity of the copper plating thickness on the hole walls. Figure 1 Taking the through-hole plated part as an example, the plating thickness at six sampling points 1 to 6 is measured and denoted as H1 to H6 respectively; then the formula for calculating the plating depth capability (TP) is:
[0053] Table 2 Performance test results of Examples 1-3 and Comparative Examples 1-2
[0054]
[0055] Note: Cl- is provided by hydrochloric acid.
[0056] As can be seen from Table 2, the copper plating additive provided by this invention can adapt to high-current electroplating operations, and the current density can be set to 50 A / dm². 2 Furthermore, the final coating exhibits high depth-deep plating capability and good coating uniformity. In contrast, Comparative Examples 1 and 2 have poor depth-deep plating capability and cannot meet the application requirements.
Claims
1. A high-current copper plating additive, characterized in that, The raw materials for preparing the copper plating additive include: brightener 0.5-2 g / L, wetting agent 20-40 g / L, and water as solvent; The brightener is sodium polydithiopropane sulfonate, sodium N,N-dimethyldithiocarbamate propane sulfonate, and 3-mercapto-1-propanesulfonic acid inner salt, with a mass ratio of (1-3):(1-5):(1-7). The wetting agent is polyethylene glycol and polyether, and the mass ratio of polyethylene glycol to polyether is 1:(2.5-3). The polyethylene glycol includes one or more combinations of PEG-4000, PEG-8000, and PEG-10000; The polyether is a propylene glycol-based polyether; The polyether has a hydroxyl value of 270-290 mgKOH / g, a viscosity of 60-80 mPa·s, and a viscosity test temperature of 25℃.
2. A method of using the high-current copper plating additive according to claim 1, characterized in that, When the copper plating additive is used, the current density is ≤50A / dm. 2 .
3. An application of the high-current copper plating additive according to claim 1, characterized in that, The copper plating additive can be used in any one of the following production lines: roll plating production line, rack plating production line, and barrel plating production line.