PI Film * Polyimide
Films (Types H & F)
Kapton Polyimide film maintains its excellent physical, electrical and mechanical properties over a wide temperature range. Kapton type H has been used successfully in applications where the temperatures have been as low as – 269°C and as high as 400°C. There is no known organic solvent for the film and it is infusible and flame resistant.
Many applications for Kapton Polyimide film are based on the fact that the excellent electrical properties for Kapton, such as dielectric strength and dissipation factor, remain nearly constant over a wide range of temperatures and frequencies. Others make use of the film’s radiation resistance or chemical resistance at elevated temperatures.
Because Kapton type H has no melting point. Dupont combines Teflon ** Fep-fluorocarbon resin with the polyimide to produce Kapton type F. The primary purpose of the Teflon Fep is to provide a heat-sealable surface on the tough non-melting polyimide base film (i.e. Kapton type F may be heat bonded to itself without the use of adhesives – the resulting insulation behaves more like a film than a wrap). In addition, the coating of Teflon Fep improves the chemical resistance of the composite film, especially to bases and concentrated acids and reduces the rate of moisture permeability and oxidative decomposition. In almost all cases, this combination of Kapton type H with Teflon Fep gives a film whose properties are arithmetic averages of the two components.
Applications for Kapton type F are based on the excellent high temperature electrical and mechanical properties of thin gauge Kapton type H plus the complete seal, moisture protection and flexibility imparted by the Teflon Fep.
* Du Pont Company registered trademark.