Cailong

In the rapidly evolving worlds of new energy and flexible electronics, a revolutionary composite material is emerging as a critical enabler for innovation: Copper-Coated PET Film, also known as composite copper foil or PET copper foil. This material represents a significant leap forward from traditional electrolytic copper foil, offering a unique combination of properties that address the pressing demands for lighter weight, enhanced safety, and greater design flexibility in modern applications.

Product Overview: A Fusion of Strengths

At its core, Copper-Coated PET Film features an innovative "metal-polymer-metal" sandwich structure. A thin, durable polyethyleneterephthalate (PET) base film, typically 4 to 6 micrometers (µm) thick, is precisely coated on both sides with an ultra-thin layer of copper, each approximately 1 µm. This architecture masterfully combines the inherent advantages of its components: the excellent electrical and thermal conductivity of copper with the outstanding physical, chemical, and dimensional stability, lightweight nature, and flexibility of the PET polymer. The result is a high-performance functional film that is versatile enough for demanding applications.

Key Advantages and Differentiating Properties

Compared to conventional copper foil, Copper-Coated PET Film offers distinct benefits:

• Superior Safety (A Game-Changer for Batteries):​ This is its most celebrated advantage, particularly in lithium-ion batteries. In the event of an internal short circuit, the thin copper layers can act as a built-in "fuse," melting quickly to interrupt the current and prevent thermal runaway. This intrinsic safety mechanism is crucial for electric vehicle and energy storage batteries.
• Lightweight & Higher Energy Density:​ The low-density PET substrate makes this composite foil significantly lighter than its all-copper counterpart. Its reduced thickness also allows for more active material within a battery cell, potentially increasing energy density by 5-10%.
• Enhanced Cycle Life and Compatibility:​ The flexible PET base can better absorb the stress from electrode expansion and contraction during charging/discharging cycles, helping to maintain structural integrity and prolong battery life. It is compatible with various battery chemistries.
• Exceptional Mechanical and Thermal Properties:​ The material inherits excellent tensile strength, chemical resistance, and thermal stability from its PET base, allowing it to withstand processing and operational stresses.

Advanced Manufacturing Process

The production of high-quality Copper-Coated PET Film relies on sophisticated vacuum and plating technologies, primarily a two-step process:

1. Magnetron Sputtering (PVD):​ A pristine PET film is fed into a vacuum chamber. Using a high-purity (e.g., 99.999%) copper target, an initial nano-scale seed layer of copper is uniformly deposited onto the film via magnetron sputtering, a Physical Vapor Deposition (PVD) technique. This step makes the insulating surface conductive.
2. Electrodeposition:​ The film then passes through a horizontal electroplating system, where the copper layer is built up to the desired thickness (e.g., 1 µm), resulting in a final product with exceptional uniformity and adhesion.

Primary Applications

• Lithium-Ion Batteries:​ As a negative electrode current collector, it is driving the next generation of safer, longer-range, and more efficient batteries for EVs, consumer electronics, and grid storage.
• Flexible Electronics:​ Its flexibility and conductivity make it ideal for Flexible Printed Circuit Boards (FPCBs), touch sensors in foldable displays, and wearable devices.
• Electromagnetic Interference (EMI) Shielding:​ Used in cables, gaskets, and enclosures to protect sensitive electronics from interference.
• Thermal Management:​ Serves as a conductive base for high-performance graphite heat spreaders or as a flexible thermal interface material, increasingly relevant for cooling high-power components like those in AI servers.

Introducing Cailong's Premium Vacuum Metallized Copper Film

At the forefront of this technology is Foshan Cailong Metallizing & Packaging Material Co., Ltd.. We specialize in producing high-performance vacuum metallized copper film on stable BOPET/BOPI substrates using advanced roll-to-roll PVD processes.

Our product stands out due to its:

• Exceptional Coating Uniformity:​ Consistent copper deposition across the film's length and width.
• Superior Adhesion:​ Copper layer adhesion strength reaches ≥5.0N/15mm, ensuring reliability during further processing.
• Excellent Thermal Stability:​ The film maintains integrity under heat, suitable for various lamination and soldering processes.
• Customization Capability:​ We offer a comprehensive range of specifications and support tailored solutions to meet specific conductivity, thickness, or dimensional requirements.

From powering the batteries of tomorrow to enabling the flexible electronics of the future, Copper-Coated PET Film is more than just a material—it's a foundational technology for innovation. Foshan Cailong​ is committed to delivering the high-quality, reliable films that our global partners need to turn these possibilities into reality.