Invar® Foil

Invar® Foil is a precision-engineered alloy foil composed of approximately 36% nickel and 64% iron, celebrated for its exceptionally low coefficient of thermal expansion (CTE), typically less than 1.2 × 10⁻⁶ /°C between −100 °C and +200 °C. This unique property ensures dimensional stability in temperature-sensitive applications, making it indispensable for precision optical instruments, aerospace tooling, and OLED fine metal masks (FMMs). Its ultra-flat, ultra-smooth, and ultra-pure manufacturing variations allow for consistent performance in photolithography and high-resolution display fabrication. Invar foil’s adaptability extends to cryogenic engineering, where it maintains predictable mechanical and electrical behavior at low temperatures. Recent advances in electroforming and surface treatment have enabled thickness control down to microns, minimizing thermal distortion while enhancing corrosion resistance. The foil’s balance of machinability, form stability, and compatibility with high-precision fabrication techniques ensures its continued role in aerospace, electronics, and scientific instrumentation, where micro-scale accuracy is mission-critical.