Rolled copper foil plays a critical role in advanced industries such as electronic circuits, new energy batteries, and electromagnetic shielding. Its performance and reliability are determined by the precision of its manufacturing process and the adaptability of its customization. This article explores the full production journey of rolled copper foil from a professional perspective and explains how it empowers modern industries through tailored solutions.
I. Standardized Manufacturing Process: Balancing Precision and Efficiency
1. Copper Ingot Casting: The Starting Point of Purity and Structure
Using high-purity electrolytic copper (≥99.99%), the material is vacuum melted and continuously cast into ingots 100–200mm thick. Cooling rates are strictly controlled to ensure fine, uniform grains and prevent cracks during subsequent rolling.
2. Hot Rolling: First Step in Thickness Reduction
Copper ingots are hot rolled to 5–10mm at 700–900°C using a reversible mill. Dynamic lubrication minimizes roller wear and relieves internal stresses from casting, laying the foundation for precise rolling.
3. Pickling: Cleaning and Activating the Surface
A nitric-sulfuric acid mix (10–15% concentration) is used to remove oxidation. An electro-polishing treatment then reduces surface roughness (Ra) to below 0.2μm, ensuring high-quality results in further rolling.
4. Precision Rolling: Achieving Micron-Level Accuracy
Multiple cold-rolling passes reduce the copper to 0.1–0.2mm. With high-rigidity mills and laser thickness gauges (±2μm accuracy), thickness variation is kept within 1%. Rolling force and tension are carefully controlled to prevent edge cracks.
5. Foil Rolling: Creating Ultra-Thin Surfaces
Advanced foil mills use micro-gap adjustment and oil-film lubrication to achieve thicknesses of 9–90μm. Surface finish exceeds ISO 1302 grade 12, suitable for 5G high-frequency skin effect applications.
6. Degreasing: Final Step for Surface Cleanliness
Ultrasonic cleaning combined with alkaline degreasing (pH 11–13) removes residual rolling oil. Carbon residue is controlled under 5mg/m², providing a clean base for surface treatments.
7. Slitting and Packaging: Industrial Precision with Aesthetic Quality
Diamond-coated blades achieve ±0.1mm width tolerance. Products are vacuum-packed in anti-oxidation film and stored in climate-controlled conditions (25±2°C, ≤70% RH) to ensure stable shipping.
II. Tailored Processing: Enhancing Industry-Specific Functionality
1. Annealing: Customizing Mechanical Properties
Soft Temper (O): Annealed at 400–600°C under H₂/N₂ atmosphere for 2–4 hours. Tensile strength drops to 200–250MPa and elongation rises to 25–40%, ideal for flex circuit dynamic bending.
Hard Temper (H): Retains work-hardened strength (400–500MPa), ensuring dimensional stability for IC substrates.
2. Surface Treatments: Functional Upgrades
Roughening: Chemical etching forms 1–2μm nodules, increasing resin adhesion to 1.5N/mm or more—solving delamination issues in 5G boards.
Nickel/Tin Plating: 0.1–0.3μm coatings offer 10× corrosion resistance, suitable for EV battery tabs.
High-Temp Coating: Zn nano-coating maintains foil stability at 300°C, serving aerospace wiring needs.
III. Empowering Key Industries through Process Innovation
Electronics: 9μm foil paired with roughening enables HDI board line widths under 12μm, powering smartphone miniaturization.
EV Batteries: Soft-temper foil with ≥20% elongation endures over 3000 ear bends, boosting battery pack reliability.
EMI Shielding: Nickel-plated foil achieves 120dB shielding at 10GHz, ideal for data center infrastructures.
IV. CIVEN METAL: Setting the Standard in Custom Copper Foil Solutions
As a leader in rolled copper foil manufacturing, CIVEN METAL has developed a flexible production system that blends standardized processes with modular customization:
Ultra-clean workshops and MES control enable ±2μm thickness and flatness ≤1I.
Programmable annealing furnaces handle up to 20 unique orders simultaneously.
Proprietary “surface treatment library” includes 12 roughening types and 8 electroplating options, with 72-hour response cycles.
Process optimization and bulk sourcing reduce custom foil prices by 15–20% compared to market averages.
From millimeter-scale ingots to micron-thin foil, rolled copper foil manufacturing is a dance of material science and precision engineering. As 5G and energy revolutions unfold, only companies that combine standardized precision with deep customization can stay ahead. CIVEN METAL is driving this transformation, helping China’s copper foil industry climb the global value chain.
Post time: Nov-19-2025