The performance of high-temperature resistant copper foil mainly stems from its special alloy composition and surface treatment process. Traditional copper foil (such as electrolytic copper foil or rolled copper foil) is based on pure copper or high-purity copper, while high-temperature resistant copper foil forms a solid solution by adding trace alloying elements (such as tin, zinc, nickel, etc.), thereby increasing the material's recrystallization temperature and oxidation resistance. For example, the addition of tin can form a copper-tin alloy layer, which forms a dense oxide film at high temperatures, preventing further oxidation. In addition, surface coating technology is also crucial. Common processes include:
Electroless nickel-gold plating: A nickel layer (1-3 μm thick) is deposited on the copper foil surface, followed by a gold layer (0.05-0.1 μm thick). The nickel layer acts as a diffusion barrier, while the gold layer provides corrosion resistance, suitable for environments above 300°C.
Organic coating: A high-temperature resistant polymer such as polyimide (PI) or silicone resin is coated to form a protective layer 5-10 μm thick, capable of withstanding short-term temperatures up to 400°C.
Ceramic coating: An alumina (Al₂O₃) or silicon oxide (SiO₂) ceramic layer is applied using the sol-gel method or physical vapor deposition (PVD) technology. Temperature resistance can reach above 600°C, but the cost is higher.
