PI mica tape is manufactured using high-quality phlogopite mica paper as the base material, with either high-temperature fire-resistant cloth or polyimide (PI) film as the reinforcement layer. The two materials are bonded together with a specialized fire-resistant adhesive, then baked, pressed and precision-slit to specification.
The polyimide film — widely known in the electronics industry as "gold finger" material because of its amber-gold appearance — brings exceptional thermal stability (decomposition temperature above 500°C), excellent dielectric properties, and outstanding radiation resistance. This combination makes PI mica tape the preferred choice for applications where both mechanical flexibility and high-voltage dielectric integrity are critical.
Unlike standard phlogopite mica tapes reinforced only with glass fiber cloth, the PI film variant delivers >7 kV per layer breakdown strength and maintains circuit integrity for 90 minutes at 600–1000V operating conditions — making it ideal for HV motor windings, generators, and mission-critical equipment insulation.
✦ "Gold Finger" Material Explained: Polyimide (PI) film is nicknamed "gold finger" in the Chinese electronics industry because of its characteristic amber-gold color and its premium status as the go-to flexible insulator for high-value electronics. It represents the top tier of flexible insulation materials.
