Copper Foil

Advantages of Copper Foil

Excellent conductivity
Copper is one of the most conductive metals, making copper foil an ideal material for electronic components such as printed circuit boards (pcbs). Copper foil is used to construct traces, pads, and other features on pcbs that require high conductivity.

Durability
Copper foil is a resilient and long-lasting material. It is resistant to corrosion and can withstand extreme temperatures and harsh environments. Additionally, copper foil is relatively easy to work with and can be folded, bent and formed without compromising its structural integrity.

Uniform thickness
Copper foil is available in a wide range of thicknesses, which is essential when working with highly precise and delicate components. The availability of uniform thickness makes it possible to get the desired results consistently.

Cost-effective
Copper foil is also cost-effective than materials that offer similar conductivity and durability. It is versatile enough to be used in a variety of applications, leading to reduced waste of material and costs to companies.

Classification of Copper Foil by Manufacturing Process and Application

Copper foil is primarily classified into electrolytic copper foil, rolled (annealed) copper foil, and composite copper foil based on differences in manufacturing processes and applications. Each type exhibits distinct performance characteristics.

1. Electrolytic Copper Foil (ED Copper Foil)

Produced via an electroplating (electrodeposition) process, electrolytic copper foil offers excellent electrical conductivity and is the current mainstream product. It is widely used in printed circuit boards (PCBs) and lithium-ion batteries.

Lithium Battery Copper Foil: Serves as the negative electrode (anode) current collector in lithium-ion batteries. Its thickness is typically less than 200 μm. Key performance indicators include thickness uniformity, tensile strength, and elongation.
Electronic Circuit Copper Foil: Used in PCBs and available in standard grades and high-performance grades. For high-frequency, high-speed applications, low-roughness HVLP (Hyper Very Low Profile) copper foil is required to minimize signal loss.

2. Rolled Annealed Copper Foil (RA Copper Foil)

Manufactured by hot pressing and cold rolling of copper ingots, rolled copper foil features excellent flexibility (bending durability) and is generally more expensive than electrolytic foil. It is primarily used in flexible printed circuits (FPCs) and high-frequency circuit boards.

3. Composite Copper Foil

Characterized by a "metal-polymer-metal" sandwich structure, composite copper foil significantly reduces weight and enhances safety. It is considered the next-generation direction for current collectors in advanced battery technologies.

Properties

Exceptional Electrical Conductivity

High-purity copper foil (≥99.7%) achieves an electrical conductivity exceeding 90% of the International Annealed Copper Standard (IACS), making it an ideal conductor for electronic circuits and battery current collectors.

Distinct Mechanical Performance

Rolled (RA) copper foil features a lamellar (flaky) crystalline structure, offering high ductility (20%–45%) and excellent flex resistance – perfectly suited for flexible printed circuits (FPCs).
Electrolytic (ED) copper foil has a columnar or needle-like crystalline structure, providing moderate tensile strength (200–450 MPa) and lower elongation (4%–15%), yet it is cost-effective and easy to thin.

Surface Characteristics Define Applications

Electrolytic copper foil typically has a shiny side and a matte side (roughness Rz 1–5 μm), which enhances adhesion to copper-clad laminates (CCLs).
Rolled copper foil is smooth on both sides (Rz <1 μm), making it ideal for high-frequency and flexible circuits.
Low-profile (HVLP) or double-smooth copper foil (Rz ≤2 μm) minimizes high-frequency signal loss.

Thermal Stability & Processability

Rolled copper foil exhibits excellent thermal shock resistance. Electrolytic copper foil often requires surface roughening and anti-oxidation treatments (e.g., zinc plating, passivation) to improve adhesion and storage stability.

Breakthrough: "Super Copper Foil" (2026)

By engineering a gradient nanostructure, the newly developed super copper foil achieves:

Tensile strength up to 900 MPa
Conductivity still ≥90% IACS
No performance degradation after six months at room temperature

This breakthrough overcomes the long-standing "impossible triangle" of strength, conductivity, and thermal stability.

Clear Thinning Trend

Lithium battery copper foil has already advanced from 6 μm down to 4.5–3.5 μm
Electronic copper foil commonly ranges from 5 μm to 105 μm

Ultra-thin foils significantly boost energy density, but also pose greater challenges in uniformity, pinhole defects, and elongation (lithium battery applications require ≥4.5% elongation).

Trade-offs Between the Two Main Types

Rolled (RA) copper foil – high flexibility, high thermal conductivity, high purity – but expensive and limited in width.
Electrolytic (ED) copper foil – low cost, easy to thin, suitable for mass production – but less flexible and has a rougher surface.

Emerging Direction: PET Composite Copper Foil

The copper-PET-copper sandwich structure offers:

Lightweight (25% weight reduction)
Intrinsic safety (fuse-like insulation upon overcurrent)

Why Choose Us

Professional team
We have modern production lines, and rigorous quality management system，as well as the strong technical team to provide customers with high-quality technical support and services.

High quality
We has rooted in the metal and mechanical processing as we working in manufacturing field for many years with rich experience，the good product quality is recognized by customers all over the world.

Quality control
We have advanced production equipment and assembly lines, professional r&d team and excellent management team，our products comply with international processes and standards from the material selection, production, quality inspection, packaging, and transportation.

24h online service
We try and respond to all concerns within 24 hours and our teams are always at your disposal in case of any emergencies.

The Production Process of Copper Foil

Electrolytic deposition
Copper foil is primarily manufactured through an electrolytic deposition process. In this process, a thin layer of copper is deposited onto a rotating stainless steel drum or titanium cathode immersed in an electrolyte solution containing copper ions. By applying an electrical current, the copper ions are attracted to the cathode surface, forming a thin, uniform layer of copper foil.

Foil separation
Once the desired thickness of copper foil is achieved, it is carefully peeled off the cathode surface. The foil is then washed to remove any residual electrolyte solution and impurities.

Rolling and annealing
To achieve the desired mechanical properties and dimensions, the copper foil undergoes rolling and annealing processes. Rolling helps to reduce the thickness and improve the uniformity of the foil, while annealing heat treatment enhances its ductility and formability.

Surface treatment
Depending on the intended application, copper foil may undergo various surface treatments to improve its adhesion, corrosion resistance, or other specific properties.
Electrodeposited zinc or nickel coatings for enhanced corrosion resistance.
Adhesive backing for easy application in certain industries.
Electrodeposited copper dendrites for improved adhesion in printed circuit boards.

Slitting and Packaging
The finished copper foil is slit to the exact width specified by the customer. After slitting, the foil is inspected for quality compliance. Once it passes inspection, the product is wound into rolls, properly packaged, and prepared for shipment from the factory.

Product Process Flow Chat

Application of Copper Foil

Electronics industry
Copper foil is extensively used in the electronics industry for the fabrication of printed circuit boards (pcbs). It serves as the conductive layer on which electronic components are mounted and interconnected. The high electrical conductivity and low resistivity of copper foil ensure efficient signal transmission and power distribution within electronic devices.

Batteries and energy storage
Copper foil plays a crucial role in the manufacturing of lithium-ion batteries, which are widely used in portable electronic devices and electric vehicles. It acts as the current collector for the battery’s anode and cathode, facilitating the flow of electrons during charging and discharging cycles. The high electrical conductivity and thin profile of copper foil enable the development of compact and efficient battery designs.

Electromagnetic shielding
Copper foil is an effective material for electromagnetic interference (emi) shielding. It can be used to create barriers that block or attenuate electromagnetic waves, preventing interference between electronic devices. Copper foil shielding finds applications in various sectors, including telecommunications, aerospace, and medical equipment, where electromagnetic compatibility is critical.

Automotive industry
Electromagnetic shielding for sensitive electronic components.
Conductive layers in automotive sensors and control modules.
Lightweight wiring harnesses for weight reduction and improved fuel efficiency.

Future Trend of Copper Foil

Ultra-thin copper foil
There is a growing demand for ultra-thin copper foil, especially in the electronics industry. Thinner foils allow for the production of more compact and lightweight electronic devices. Manufacturers are continuously working on developing copper foil with thicknesses as low as 5 microns or less while maintaining its essential properties.

Improved surface treatments
Research is ongoing to develop advanced surface treatments for copper foil to enhance its performance and compatibility with various substrates. These treatments aim to improve adhesion, corrosion resistance, and electrical properties, enabling the use of copper foil in a wider range of applications.

Sustainability and recycling
With increasing environmental concerns, there is a focus on sustainable practices in the copper foil industry. Efforts are being made to optimize the manufacturing process, reduce waste, and promote the recycling of copper foil. Developing closed-loop recycling systems and increasing the use of recycled copper in foil production are key areas of interest.

Emerging applications
Flexible electronics: Copper foil is being explored for use in flexible electronic devices, such as wearable technology and flexible displays.
Advanced energy storage: Copper foil is finding new applications in advanced energy storage systems, including solid-state batteries and supercapacitors.
5g technology: The deployment of 5g networks requires efficient shielding and high-frequency capabilities, creating new opportunities for copper foil in telecommunications infrastructure.

Copper Foil the Shining Metal in Modern Industries

Copper foil, as a kind of metal material, has been used for centuries in various industries. Nowadays, copper foil is more widely applied in many modern industries, such as electronics, energy, aviation, and construction. With its excellent characteristics, copper foil provides comprehensive solutions to meet the demands of various industries.

First of all, copper foil is widely used in the electronics industry. As the foundation of the printed circuit boards (pcbs), copper foil provides excellent conductivity and uniformity, which ensures the fast and stable transmission of electric signals. With the development of 5g networks and the internet of things (iot), copper foil demand in the electronic industry will continue to grow in the future.

Secondly, copper foil also plays an important role in the energy industry. Copper foil is widely used as a crucial component in lithium-ion batteries, which are widely applied in electric vehicles, tablets, laptops, and other electronic devices. With the increasing demand for green and renewable energy, copper foil will become more critical in energy-related applications.

Moreover, copper foil has high corrosion resistance, making it suitable for aviation and marine applications. With its excellent mechanical strength, copper foil is widely used in heat exchangers, transformers, and other equipment in aviation and marine industries.

Last but not least, copper foil is extensively used in the construction industry. Copper foil has a unique color and luster that give buildings an elegant and classic look. Copper foil is also a sustainable and durable material that can be recycled and reused. Many architects and designers choose copper foil as a roofing material or decoration material to add aesthetic value to their projects.

How To Choose The Right Copper Foil For Your Works Of Art

Foil width
You might be inclined to select foil that creates skinny lines, however they are not as strong. That’s because you can’t apply as much solder. For most projects, you’ll find 7/32” copper foil will be suitable, however if you vary the width of the foil it will add more depth. If you’re using thicker glass, 1/4" foil will create a seam of normal width. But if you want special effects, take a razor knife and trim the copper foil after you apply it to the glass. Creating distance in your piece can be done by making the foil lines thinner in a gradual way. For that, you’ll want 3/16” or 5/32” copper foil used sparingly to add these touches of details.

Foil thickness
Foil is measured in mils. The thinnest is 1 mil. Cheaper foil will tear too easily, particularly around curves, but good quality foil will tear much less even at this size. It will still be delicate though so you’ll need to be gentle. While cheaper foil is certainly cost effective, spending a little more on quality is going to ensure you won’t have to go back and patch up any tears, a very time-consuming process.

Color of backing
One of the last things you must consider when choosing the right copper foil is what color your backing is. The basic rule for this is to think about the finish. If you’re not applying patina, silver black foil will work nicely. If you’re using copper or black patina, copper-backed or even black-backed foil will be a good fit. For opalescent glass, the backing isn’t really an issue because the foil color won’t be so noticeable.

Chracteristics of Copper Foil

Copper foils function is to allow us to assemble the glass pieces with solder. Since solder doesn't stick to glass, copper foil is used as the foundation to build on. If we think about houses for a moment, a poor foundation results in a poorly structured house built on top of it. The same goes for the foil used in stained glass with out solder on top.

The foil needs to be flexible to form around all of the shapes we want to make with glass. This means that it needs to be a little stretchy so that it won't tear or split when forming to inside curves.

The softness of the foil is also important in allowing it to stretch but I've personally noticed that softer foil sits smoother and takes the shape of heavy textured glass much better too.

The copper foil should also be strong and adhere well so that we can burnish it (rub it smooth) and remove all of the kinks without tearing it accidentally.

Types of Copper Foil

Calendered copper foil
This copper foil is made by melting and processing copper into copper sheets, which are then repeatedly rolled and tied to make the original foil, and then the original foil is subjected to a series of surface treatments such as roughening treatment, heat treatment, and anti-oxidation treatment according to requirements. The width of calendered copper foil is difficult to meet the production requirements of rigid ccl and lithium-ion battery anion sheets due to the limitations of the processing process. However, the calendered copper foil has a lamellar crystalline structure, so it has better strength and toughness than electrolytic copper foil.

Electrolytic copper foil
This copper foil is made by dissolving copper into copper sulfate electrolyte and then electrodepositing the copper sulfate electrolyte in special electrolytic equipment under the action of direct current to make the original foil. The foil is then subjected to a series of surface treatments such as roughening treatment, heat treatment, and anti-oxidation treatment according to requirements. The electrolytic copper foil differs from the calendered copper foil in that the two sides of the original electrolytic foil have different crystalline forms, with the side close to the cathode roller being smooth and becoming glossy.

Single surface treated copper foil
Among the electrolytic copper foils, the most produced variety is the single-sided surface-treated copper foil, which is not only the most used type of electrolytic copper foil in the manufacture of copper-clad and multilayer boards but also the copper foil with the largest application range. In the mid-1990s, another type of low-profile copper foil (lp) emerged among such products.

Double-sided (reversed-phase) processed copper foil
Mainly used for fine lines of multilayer circuit boards, its glossy surface has a low profile, and this surface is laminated with the substrate to make a copper-clad board that can maintain a high precision line after etching. The demand for this type of copper foil is increasing.

Our Factory

HSMetal is a technology-driven enterprise dedicated to the design, R&D, manufacturing, and sales of advanced copper foil products. Our portfolio features a range of high-end copper foil solutions such as ultra-thin flexible lithium battery copper foil, HVLP high-frequency high-speed ultra-low profile foil, RTF reverse treated foil, ultra-thin carrier foil (peelable copper), blackened foil, buried resistance foil, and microporous copper foil.

With years of specialized experience in R&D and production of ultra-thin flexible copper foil for lithium batteries, we have built a strong track record of delivering high-performance products alongside comprehensive technical support and customized solutions to clients worldwide.

The ultra-thin electronic copper foil series developed by our company exhibits outstanding stability and reliability, making it suitable for a wide array of applications. These include multi-layer printed circuit boards (PCBs), flexible circuit boards, IC packaging substrates, 5G smartphones, servers, base stations, AI-integrated systems, automotive radar, medical devices, and aerospace technologies.

As a critical material in both the lithium battery and electronics industries, copper foil plays an essential role in enabling technological progress. We remain committed to advancing innovation through sustained R&D, continuously improving product quality, and expanding our development of lithium-ion battery materials. Our goal is to consistently provide superior customer service and contribute to the sustainable, high-quality growth of the industry.

Electrolytic Copper Foil

Microporous Copper Foil

Rolled Copper Foil

Production Line

Quality Control

R&D Capabilit

FAQ

Q: What is copper foil used for?

A: Copper foil is a thin sheet of high-purity copper (typically ≥99.7% for electronic grade) produced either by electrodeposition (electrolytic process) or mechanical rolling (rolled/annealed process). It serves as a fundamental conductive material in printed circuit boards (PCBs), lithium-ion battery anodes (current collectors), electromagnetic shielding, and various other electronic applications.

Q: How do you make copper foil?

A: The manufacturing of copper foil is a high-end industry in which copper is electrodeposited from an electrolyte onto a rotating drum. The electric loop is closed again by positioning mmo anodes on opposite sides of the drum. During the process, the copper foil grows on the drum.

Q: What is the skin effect of copper foil?

A: The skin effect refers to a confinement of current near the surface of a conductor when the current oscillates at high frequency. For a perfectly smooth conductor, the skin effect is marginal until you get up to ghz frequencies.

Q: What is copper foil made of?

A: Thin copper foils are either produced by electrodeposition or rolling. For electrodeposition high grade copper has to be dissolved in an acid to produce a copper electrolyte. This electrolyte solution is pumped into partially immersed, rotating drums which are electrically charged.

Q: Does copper foil rust?

A: Copper will never rust for the same reason as bronze — it contains too little iron. Though it will not rust, copper can form a green film, or patina, on its surface over time. However, this patina will not flake the way rust does. Instead, it creates an even, thick coating on top of the copper itself.

Q: Is aluminum foil made of copper?

A: Aluminum foil is characterized by its alloy and the material state. Pure aluminum (i.E., 100%) does not exist on the market, but other metals and semimetals are bonded to the aluminum in an alloy. These are mainly chromium, copper, iron, magnesium, manganese, silicon, titanium and zinc.

Q: Is the foil made of pure aluminum?

A: Aluminum foil is 98.5% aluminum with the balance primarily from iron and silicon to give strength and puncture resistance. The molten alloy is rolled thin and solidified between large, water-cooled chill rollers. During the final rolling, two layers of foil are passed through the mill at the same time.

Q: What is the resistance of copper foil?

A: For example, at 25°c, the resistance value of copper foil of width 3 mm and length 50 mm, calculated as follows, is 8.17 mω. From this resistance value, the voltage drop when a 3 a current flows is 24.5 mv. If the temperature rises to 100°c, from the graph we see that the resistance value increases 29%.

Q: What is the thickness of copper foil?

A: In pcb manufacturing, the copper foils are in rolls, which are electronic grade with purity of 99.7%, and thickness of 1/3oz/ft2 (12μm or 0.47mil) – 2oz/ft2 (70μm or 2.8mil).

Q: What is the thermal conductivity of copper foil?

A: The thermal property measurement results indicate that the cu-rgo film exhibits excellent thermal conductivity (637.7 w m−1 k−1) and relatively low cet.

Q: Is copper foil antimicrobial?

A: It's widely recognised that materials such as copper and silver can play an important role in preventing the transmission of bacteria and viruses. In particular, it is proven that copper is an extremely effective antimicrobial material, capable of inactivating or killing bacteria within a short space of time.

Q: Is copper foil real copper?

A: Copper foil is a thin sheet of copper metal that is widely used in various applications due to its excellent electrical conductivity, malleability, and corrosion resistance.

Q: How is copper foil made?

Q: What is the thickest copper foil?

A: Thickness - copper foil is usually available in 1mm and 1.5mm thicknesses. Some are also available in 1.25mm thick. Backing colour - foil backings are available in 3 colours; silver, copper and black. Normally the colour selected is determined based on the finished colour of the solder you plan to use for your project.

Q: What size copper foil to use?

A: The most common sizes really are 3/16″ and 7/32″ and occasionally 1/4″ for the wide stuff. We start our beginner students with 7/32″ because it is easier to get the foil centered on the glass. After some experience, we recommend going down to 3/16″.

Q: Does copper foil conduct electricity?

A: There are several benefits of using copper foil in electronics projects: 1. Conductivity: Copper is an excellent conductor of electricity, making it ideal for use in electronic circuits.

Q: Does copper foil oxidize?

A: If you just left it on a shelf for many years, it would go from shiny to dull brown. If it were outside it would turn brown in a year and green in a few years. If it's ancient and has been exposed to air, then it does lose some of its adhesive quality due to oxidation.

Q: Why wont my copper foil stick to glass?

A: Oil from your cutter, grinder dust, and even people grease will inhibit the adhesive properties of your foil. Some artists like to use alcohol pads to clean their glass, but I've found that nothing beats good ol' fashioned dish soap & water.

Q: What are the different types of copper foils?

A: In a broad sense, there are two types of copper foil used: Rolled copper and electro-deposited (ed) copper. Within these two types there are a tremendous amount of vari- ants.

Q: Is copper foil malleable?

A: It is a highly malleable and ductile metal, a good conductor of heat and when very pure, a good conductor of electricity.

As one of the leading copper foil manufacturers in China, we warmly welcome you to buy high quality copper foil at competitive price from our factory. For more cheap products, contact us now.

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