Electroplating is a unique method of coating a metal substrate with another metal to increase its corrosive resistance and aesthetic appeal while providing the mechanical properties of the underlying metal.
This surface finishing treatment has been widely used in different industries because of numerous advantages.
Do you know that the market size of electroplating is projected to reach USD 16.89 Billion by 2028? The rapid market growth is the result of perks of copper layering. It improves the functionality of the metal and increases its durability.
But what is electroplating and how does electroplating work?
In this detailed guide, we will discover how to copper plate and what are its application range. Whether you demand aesthetic finishes or improving functional properties, copper electroplating is a reliable process you can leverage on.
What is Copper Electroplating: A Brief Overview
Copper electroplating is coating a thin copper film on a metal substrate. You can carry out the process in copper sulfate electrolysis.
The material to be plated is submerged in the solution of copper ions as it acts as a cathode, and copper rod/ wire acts as an anode. Typically, it consists of a copper sulfate solution known as an electrolyte.
Pre-treatment such as cleaning and activation, is essential to ensure no residual dust, oils, or polishes remains on the surface. Usually, the standard cleaning treatment is taken place in an alkaline solution. This procedure provides proper adhesion of conductive layers on the surface.
When the electric current passes through the solution, copper ions from the anode dissolve and travel to the material substrate (cathode).
The copper ion carries the negative charge and deposits on the surface of the metal after reaching the cathode. It disperses uniformly over the surface of the metal, improving its properties such as thermal and electrical conductivity.
Electroplating Material Options:
Generally, electroplating has a wide range of material options due to its versatility and accessibility. You can use different types of metallic and non-metallic coating on the substrate to achieve specific requirements.
What is the difference between metallic and non-metallic coatings?
In metallic plating, the elements that contain the physical and chemical properties of metals such as metal alloy and stainless steel. However, non-metallic coatings do not have any metal elements.
Let’s discuss the material options widely used for electroplating;
The most common material used for electroplating is metal because various metals are coated on a substrate to enhance their quality and durability. These metal electroplating are efficient for increasing the plated material’s hardness, conductivity, corrosion, and impact resistance.
Following are the metal material options utilized widely for steel plating;
You can coat a glass substrate with different metal coatings to achieve a conductive and reflective surface for the specific application. Copper, silver, and gold are the primary coating option for electroplating the glass surface.
Ceramics have been electroplated with metal for years to increase the aesthetic appearance, wear resistance, and strengthen the product. A thin layer of gold, nickel, silver, and copper is deposited on the ceramic surface, increasing the product’s reliability.
Plastic electroplating is a standard method used to coat metal ions on the plastic substrate to amplify metal properties while retaining the plastic properties. Copper is an ideal choice for electroplating metal on plastic. Some most common plastic materials used for metal finishes include;
- Polycarbonate (PC)
- ABS PC
- Acrylic (PMMA)
- Polylactic acid (PLA)
Related Read: Plastics vs Polymers: Differences and Applications
Major Copper Electroplating Techniques:
Although the technique used for copper electroplating is much generalized because it mainly consists of an anode and cathode in an electrolytic solution. However, different experts used several electroplating techniques to achieve additional industrial requirements.
For example: Some projects require plating control, specific adhesion, thickness, and improved grain structure. In different techniques, experts use various chemicals and additive materials as levelers, accelerators, or suppressors to control the plating process.
Therefore, experts use different copper electroplating methods to accomplish the desired specifications.
Following are the four most frequently used copper electroplating techniques;
1. Dual Damascene Plating:
The dual damascene plating process involves dielectric such as silicon dioxide on the substrate. Vias and trenches are patterned on the dielectric surface and coated with a thin barrier layer. After that, copper ions are deposited inside via patterning.
Now, excess copper is removed with suppressors. At last, we use levelers for the final capping layer.
You can use the TA-based barrier layer for a deposition because it is ideal for preventing the copper ions from drifting towards interlevel dielectric (ILD). It also ensures strong adhesion and thickness of the part.
2. Through-Silicon Via Plating:
It is a complex process to achieve the desired thickness by depositing the copper ions in the vias. The process is similar to damascene plating but creates conductive paths from one side of the wafer to the other.
After the plating process, suppressors and levelers remove the extra top layer of copper, ensuring a flat surface.
TVC plating is an advanced process that involves a thin layer of suitable barrier to reduce copper diffusion. You can use this process to improve the electrical conductivity and channel electrical signals to pass through the wafer.
3. Copper Pillar Plating:
In integrated circuits (ICs), copper pillar plating provides a reliable electrical connection with copper pillars. In this process, the photoresist mask is patterned with copper pillars to distinguish the location.
The current is applied while the substrate is immersed in the copper plating solution to deposit copper ions on the substrate. You can continue the plating process until you achieve desired pillar height.
Lastly, the planarization process eliminates the excess copper and uniformizes the surface. If you want higher density and electrical performance, copper pillar plating is the right solution for you.
4. Redistribution Layer Plating:
RDP is a phenomenon of creating an extra patterned layer of metal that redistributes the electrical connections of an integrated circuit (IC). The substrate surface is coated with a thin dielectric material in this method.
After that, a photoresist mask is used to define the RDL pattern that you want to achieve.
Once done with the patterning, you can submerge the substrate in the electrolytic solution with copper ions and start the current flow. The current will let the copper ions migrate and deposit on the substrate surface. You can repeat the process until the required thickness is attained.
The DLP process provides optimum uniformity and precision, making it ideal for various precise applications.
The Benefits of Copper Electroplating:
As we have been discussing the working and different copper electroplating techniques, you must be wondering what benefits this modern manufacturing process includes.
Let’s discuss some of the extraordinary advantages of copper electroplating that make it the first-priority choice for different applications;
1. Increased Conductivity Advantage:
Since we all know that copper is an excellent conductor of heat and electricity, it is one of the most widely used metals for electroplating because it increases the electrical performance of the plated material. Copper plating is an efficient choice for electronic device applications.
2. Excellent Corrosion Resistance:
What makes copper superior to other electroplating material options is its corrosion-resistant properties. It is impervious to rust because it maintains a protective barrier over the substrate—this property of copper plating increases the product’s average lifespan, durability, and performance.
3. Strong Adhesive Bond:
Another reason for durable copper plating is its strong adhesion characteristic. Copper creates a strong bond between substrate and coating, allowing long-lasting durability without issues such as peeling or delamination.
In addition to metals, copper plating is convenient with different materials such as glass, ceramics, and polymers.
4. The Versatility of the Process:
From an applications perspective, the copper electroplating process is versatile and accessible for a wide range of applications. Copper electroplating is widely used for electronic, automotive, telecommunication, aerospace, and decorative purposes.
Moreover, you can use these different techniques to create complex geometries, thicknesses, shapes, and sizes.
Copper electroplating is far more sustainable and eco-friendlier than other electroplating materials. The entire process is chemical and health hazards free, reducing the overall environmental impact. Also, copper is recyclable material; thus, the process is sustainable.
One of the critical advantages of copper electroplating is its affordability. As copper is a relatively budget-friendly and abundantly available metal, it makes the process less costly and more effective.
Copper electroplating is suitable for industrial applications as it offers precise performance at a low cost.
Confused whether copper is the right choice for you or not?
Check Out: Bronze Vs. Copper: Choosing Between Two Great Metals
The Limitations of Copper Electroplating:
From strong adhesion to cost-effectiveness, copper electroplating provides outstanding advantages. However, there are certain constraints to the process.
So, before you get started with it, consider the following limitations of copper electroplating service;
1. Substrate Compatibility:
The most prominent limitation of the copper electroplating process is substrate compatibility. Determining the compatibility between metals with the particular solution is crucial to ensure successful electroplating.
Usually, you must perform pre-treatments or add additives during the process, making the process costlier and more complex.
2. Safety Hazards:
There are several health risks associated with the electroplating process. The workers who perform the method are at risk of suffocation due to continuous hexavalent chromium exposure.
Moreover, they must complete the electroplating method with standard precautionary gears to prevent skin infections and chemical burns.
3. Geometric Constraints:
Copper electroplating is beneficial for micrometers to millimeters; thus, if you want to achieve thicker coating, you must perform multiple coating cycles with additive treatments.
Moreover, the process is not consistent with providing uniform thickness on complex geometries.
4. Surface Pre-treatments:
The process requires extensive surface pre-treatments before the process to ensure the coatings successfully adhere to the metal substrate. Any defect in the substrate surface results in an inefficient electroplating process.
Different Types of Copper Electroplating Baths:
Different types of electroplating baths are used in various industries for depositing metal on the substrate. In terms of copper electroplating, we have three primary options for bathing. It includes an acidic, alkaline, and electroless plating bath.
1. Typical Alkaline Copper Baths:
It is difficult to apply and then control the bathing process; however, it significantly improves the functionality of the substrate. Alkaline copper baths are categorized into three major types that you can use according to your requirements;
- Alkaline Cyanide Solutions
We deposit copper and cyanide as the metal coating in this process. It provides a robust and strongly adhesive layer that is highly functional. However, there are some drawbacks such as difficulty in handling, safety hazards, and special handling.
- Alkaline, Non-Cyanide Solutions
Despite having tremendous benefits, cyanide is a highly toxic material. Therefore, you can consider non-cyanide solutions for coating the metal because it is safe and provide satisfactory results.
But cyanide is less effective than these solutions in terms of efficiency and effectiveness.
- Pyrophosphate Copper (Mildly Alkaline)
It is an ideal technique for minimizing the current transmission loss because this process possesses strong throwing power. It produces low-stress copper deposits with high ductility, so you don’t need to worry about cracks
2. Acid Copper Baths:
Acid copper baths are a typical way of depositing copper coating fast and effectively on the substrate. It has good throwing power and evenly distributes the layers over the surface. It is easy to control and cost-effective while ensuring a thick copper coating.
It is a high-speed electroplating process that can operate under various conditions, such as temperature, density, and flexibility.
3. Electroless Copper Plating Bath:
The most advanced feature of this process is that you can use it for coatings on non-conducting materials such as plastic and glass.
These baths do not involve electric current and thus can deposit a coating on non-conducting substrates. This process provides consistent thickness with uniform layering.
Through-hole plating and plastic coating are common examples of the electroless copper plating bath.
The 8 Main Industrial Applications of Copper Electroplating:
Copper is an essential part of industrial applications across different sectors. According to the report, the copper market is growing immensely and is expected to register a CAGR of more than 6%. Let’s discuss the major industrial application of copper electroplating
1. Electrical Wiring:
The electricity transmission and conductivity characteristics make copper electroplating suitable for electrical wirings. It provides high transmission power and flexibility to the electrical wires.
In aerospace, copper electroplating is used for EMI/RFI Shielding with conductive coatings. It is excellent corrosive resistance; thus, used in the aerospace industry for surface finishes.
3. Renewable Energy:
Copper is ideal for renewable energy applications such as solar panels and electric vehicles. It is cheaper alternative to silver and other high conductive materials. Copper is a sustainable, cost-effective, and reliable material for renewable energy production.
The automotive industry is the primary application of copper electroplating. In the automotive sector, people use this technique for heat dissipation, corrosion resistance, electric contact, and component repair.
5. Medical and Dental:
This electroplating process has a wide range of applications in the medical and dental industries. It is used for manufacturing dental appliances, medical implants, fillings/crowning, and surface coating of medical instruments to enhance resistance and performance.
The electroplating process has significant applications in designing different functional prototypes because it is low-cost and adds extra strength to the prototype. Rapid prototyping and mold-making are typical applications of copper electroplating.
Copper electroplating is a standard process in the jewelry industry. Typically, brass metal coating, decorative coatings, and oxidation are used to enhance the rust resistance and appearance of the jewelry.
- Art and Home Décor:
Copper is a significant constituent of crafting compelling wall art, copper sculptures, artistic home décor, and decorative finishes.
Get Aesthetic Metal Parts with Kemal’s Finishing Services:
Are you looking to make your metal parts functional and aesthetic? Kemal offers a variety of copper electroplating surface finishes options to fit your application demand.
At our facilities, we closely understand customers’ demands to provide a customized solution.
Our qualified team of engineers and product developers ensure that your metal parts get premium-quality coating without any inconsistencies.
With rigorous quality control, you can trust Kemal for copper electroplating solution and surface finishing services.
Before You Go:
Before you go, we invite you to check out other high-quality and industrial standards services of Kemal. We offer top-priority injection molding, CNC machining, and mold manufacturing.
If you have any queries, you can always reach out to us. We are available for 24/7 assistance. For a free quote, contact us.