Definition

Kapton is DuPont's trade name for polyimide film, the dominant base material for flexible circuits. Properties: excellent thermal stability (-269°C to +400°C), high dielectric strength, good chemical resistance, and inherent flexibility. Standard thickness is 25µm (1 mil) or 50µm (2 mil). Kapton's amber color is distinctive. Alternatives exist (Apical, Upilex) but Kapton remains the reference. Kapton HN is general purpose; Kapton FN has fluoropolymer coating for better adhesion. Cost is significantly higher than FR-4. Used in flex circuits, aerospace, and high-temperature applications.