Electrolytic Copper Foil vs. Rolled Copper Foil

In today's rapidly evolving technological landscape, copper foil stands as an indispensable material in the manufacture of electronic products. Among the different types of copper foil, electrolytic copper foil and rolled copper foil are undoubtedly two prominent stars. With over 30 years of technical expertise, Jintian Copper has showcased remarkable advantages in the manufacturing process and physical performance of their copper foil. Today, let's witness a "duel of the dual stars" in the world of copper foil to see which is superior between electrolytic copper foil and rolled copper foil.

Copper Foil Manufacturing Process

When discussing the copper foil manufacturing process, electrolytic copper foil and rolled copper foil have distinctly different production processes. Electrolytic copper foil is made through electrochemical deposition. Simply put, copper is dissolved in sulfuric acid to form a copper sulfate electrolyte. Then, in the foil-forming machine's electrolysis bath, direct current causes the copper sulfate electrolyte to deposit on the cathode roller surface, forming raw foil. Continuous rotation of the cathode roller and consistent stripping of the copper foil eventually gather into coil-shaped copper foil. Although this process sounds complex, it is relatively simple to operate and has a lower cost.

On the other hand, rolled copper foil is manufactured through a physical rolling process. It requires heating the copper block and repeatedly rolling it until the desired thickness is achieved. This rolling process gives rolled copper foil a fibrous grain structure, with high ductility and flexibility. However, the production process is more complex and costly. Currently, only a few companies worldwide can mass-produce rolled copper foil, making it more scarce and competitive in certain fields.

Physical Properties

In terms of physical properties, electrolytic copper foil and rolled copper foil also show significant differences. Electrolytic copper foil has a columnar grain structure that is relatively regular but more brittle. This makes electrolytic copper foil prone to cracks and breaks when bent or folded, resulting in less flexibility. In contrast, rolled copper foil has a fibrous grain structure, offering much better flexibility. It does not easily crack when bent or folded, making it ideal for applications in flexible circuit boards that require frequent bending.

Besides flexibility, ductility is another crucial metric for assessing copper foil performance. In this regard, rolled copper foil again excels. Rolled copper foil can withstand more stretching and deformation without breaking. In contrast, electrolytic copper foil has lower ductility and tends to break under stretching during processing.

Moreover, surface smoothness differs between electrolytic copper foil and rolled copper foil. Electrolytic copper foil's surface is relatively rough, which can increase adhesion with other materials in certain applications. However, for precision circuit boards, a smoother surface is usually preferred. Rolled copper foil offers a smoother surface due to mechanical compression during rolling, making it suitable for high-precision processing scenarios.

Electrical Performance

As a conductive material, the electrical performance of copper foil is a crucial quality metric. How do electrolytic copper foil and rolled copper foil perform in this regard?

Although the difference in electrical performance between electrolytic copper foil and rolled copper foil is not substantial, rolled copper foil is favored in applications demanding high electrical performance due to its higher purity and better grain structure. Rolled copper foil's electrical performance is slightly superior to that of electrolytic copper foil, providing advantages in high-precision conductivity applications.

However, this does not imply that electrolytic copper foil lacks advantages in electrical performance. Due to its lower manufacturing costs, electrolytic copper foil is widely used in cost-sensitive applications. For instance, in simple display connectors or fixed flexible circuit parts, electrolytic copper foil is preferred for its cost-effectiveness.

Application Scenarios

In terms of application scenarios, both electrolytic copper foil and rolled copper foil have their unique strengths. Due to its lower manufacturing costs and decent conductivity and corrosion resistance, electrolytic copper foil is broadly used in various electronic products. For example, it plays a crucial role in the manufacture of printed circuit boards (PCB), flexible circuit boards (FPC), LED lighting, LCD screens, flat-panel TVs, and more. Additionally, electrolytic copper foil is often used in solar panels' conductive layers, enhancing their conversion efficiency and stability. In semiconductor packaging, electrolytic copper foil serves as a metal substrate, offering excellent heat dissipation, lead-bearing, and reliability characteristics.

In contrast, rolled copper foil is extensively used in flexible circuit boards requiring frequent bending, moving, or rolling due to its excellent flexibility and fatigue resistance. For example, in foldable phones, wearable devices, camera modules, and other applications demanding high bend resistance, rolled copper foil is the best choice. Furthermore, rolled copper foil is broadly applied in flexible copper-clad laminates (FCCL), 5G communication, electromagnetic shielding, heat dissipation substrates, graphene film preparation, aerospace, lithium batteries, smart vehicles, drones, and more. In these fields, rolled copper foil's unique advantages—high strength, high conductivity, high flexibility, and low roughness—make it an indispensable material.

Cost and Thickness Options

Electrolytic copper foil and rolled copper foil also differ significantly in terms of cost and thickness options. The simpler manufacturing process of electrolytic copper foil results in lower costs, giving it an edge in cost-sensitive applications. For example, in simple display connectors or fixed flexible circuit parts, electrolytic copper foil is favored for its cost-effectiveness.

On the other hand, rolled copper foil's more complex manufacturing process results in higher costs, making it more competitive in high-performance, high-durability applications. For instance, in foldable phones and wearable devices requiring high bend resistance, rolled copper foil is highly esteemed for its exceptional flexibility and fatigue resistance.

Regarding thickness options, rolled copper foil can typically be produced in thinner variants, catering to ultra-thin FPC design needs. If flexible circuit boards require frequent bending or use in high-performance environments, rolled copper foil is undoubtedly a better choice. Although electrolytic copper foil can also be produced in various thicknesses, its performance may not match rolled copper foil's in ultra-thin, high-precision applications.

Conclusion

Through the above comparisons and analyses, we can see that electrolytic copper foil and rolled copper foil have distinct differences in manufacturing process, physical properties, application scenarios, cost, and thickness options. Each holds prominence in the copper foil industry with its unique advantages.

Electrolytic copper foil, with its low manufacturing cost, stable conductivity, and excellent corrosion resistance, is widely applied in various electronic products. Meanwhile, rolled copper foil, with its superior flexibility and fatigue resistance, plays an irreplaceable role in flexible circuit boards requiring frequent bending, movement, or rolling.

In today's rapidly advancing technology landscape, as a crucial material in the manufacture of electronic products, the performance and application prospects of copper foil are continuously expanding and upgrading. Whether it is electrolytic copper foil or rolled copper foil, each plays a vital role in their respective fields, collectively driving the development and progress of the electronics industry.

With over 30 years of experience, Jintian Copper has focused on the copper processing field and has become a global leader in copper and copper alloy materials supply due to its strong technical prowess and innovative capacity. Jintian Copper has won the trust of global customers, leading the copper processing industry's development with its excellent product quality and comprehensive service system.

In the future, with the continuous advancement of technology and the increasing performance demands of electronic products, copper foil materials will face more challenges and opportunities. We look forward to electrolytic copper foil and rolled copper foil continually innovating and breaking through in future developments, contributing more to the electronics industry's progress.