Invar® Foil (Light Tight)

Invar® Foil (Light Tight) is a nickel–iron alloy foil containing approximately 36% nickel, engineered to block light transmission while maintaining an ultra-low coefficient of thermal expansion (CTE). This combination ensures exceptional dimensional stability for precision applications requiring both optical shielding and micro-scale accuracy. It is extensively used in fine metal masks (FMMs) for OLED displays, optical instruments, and aerospace calibration systems where light leakage could compromise performance. Light-tight Invar foil is manufactured with extreme quality controls—ultra-purity, ultra-smooth surface, ultra-flat shape, and ultra-precise dimensions—achieved through advanced smelting and electrolytic forming. Multi-beam ultrafast laser micromachining enables intricate patterning without thermal distortion, critical for high-resolution OLED shadow masks. With a thickness down to 8 μm, the foil provides consistent stability under temperature fluctuations while resisting environmental degradation. Its unique synergy of thermal control, optical isolation, and precision manufacturability secures its place as a vital material in cutting-edge electronics and metrology.