Kapton® MT Polyimide Disk

Kapton® MT is DuPont's thermally conductive polyimide film — a ceramic-filled grade with a thermal conductivity approximately three times higher than standard Kapton® HN. This is the only property that fundamentally distinguishes it from HN: where standard polyimide insulates but conducts heat poorly, MT conducts heat significantly better while retaining full electrical isolation. It bridges the gap between standard polyimide films (thermally insulating) and ceramic thermal interface pads (thermally conducting but brittle and inflexible), occupying the position of a flexible, die-cuttable thermal interface material that simultaneously functions as an electrical isolation layer.

Specify MT whenever heat dissipation through the film is a design requirement alongside electrical isolation. In power electronics, LED modules, EV battery packs, and motor windings, the primary failure mode is thermal — heat generated in the device accumulates because the insulating film between the device and the heatsink conducts too slowly. MT removes this constraint. In applications where the film is purely a dielectric spacer or mechanical insulator and heat flow through it is not a limiting factor, standard HN is appropriate and lower cost. The ceramic filler in MT also increases stiffness and modulus and slightly reduces dielectric strength relative to HN — confirm these trade-offs are acceptable before substituting MT in purely electrical applications.

Ceramic thermal interface pads — aluminium nitride, alumina — are more thermally conductive than Kapton® MT but are rigid, brittle, and require careful handling to avoid cracking during assembly. Kapton® MT can be die-cut to component footprints, compressed between surfaces for intimate thermal contact, integrated into multilayer thermal stacks, and handled in continuous roll-to-roll processes. Where an application requires a thermal interface layer that is flexible, conformable, die-cuttable, and also provides electrical isolation, MT is the correct choice over a ceramic pad. For applications requiring very high thermal conductivity, ceramic substrates or graphite-filled pads with higher thermal performance may be needed.

Yes. Despite its enhanced thermal conductivity, Kapton® MT maintains strong dielectric performance — with high dielectric strength, volume resistivity exceeding 10¹⁶ Ω·cm, and a UL 94 V-0 flame rating. This makes it uniquely qualified as a thermal interface material that simultaneously functions as an electrical isolation layer between power devices and heatsinks. The trade-off versus standard HN is a moderate reduction in dielectric strength and a slightly higher dielectric constant due to the ceramic filler — verify these values for your application on the full datasheet before specifying in high-voltage designs.

Kapton® MT shares the full Kapton® family thermal range — −269 °C to +400 °C continuous service — which is unchanged by the ceramic filler. This means MT can be used across the complete temperature range of power electronics operation, solder reflow during assembly, and the cryogenic environments of certain scientific instruments and aerospace platforms, without degradation of either its thermal or electrical performance.

Kapton® MT is specified for EV battery thermal management — as an electrically isolating thermally conductive inter-cell film and bus bar insulator; power electronics substrates and IGBT/SiC module base plates where heat must pass from the die to the heatsink through an electrically isolating film; high-power LED module thermal interface layers where junction temperature control directly determines output and lifetime; motor slot insulation in traction motors and industrial drives where winding hot-spot temperatures are reduced by better heat flow through the insulation; aerospace avionics modules where thermal management and electrical isolation must be solved simultaneously in compact, weight-constrained packages; and flexible thermal interface films replacing ceramic or graphite TIMs in portable electronics, power converters, and telecom equipment.

Yes. The higher modulus of Kapton® MT compared with standard HN — a consequence of the ceramic filler — improves its cut-through resistance and mechanical robustness under the compressive loads typical of thermal interface assemblies, where the film is clamped between device and heatsink surfaces. It does not creep or deform under sustained mechanical pressure, which is important for maintaining thermal contact resistance stability over the service life of the assembly.

Kapton® MT carries a UL 94 V-0 flame rating and resists the greases, coolants, lubricants, and impregnating varnishes and resins used in motor manufacturing and battery assembly. Its flame retardance and chemical stability make it suitable for EV battery module thermal management and motor insulation where thermal runaway resistance and long-term chemical compatibility are essential safety requirements.

Kapton® MT can be die-cut, laser-cut, and incorporated into multilayer thermal management stacks. It is available in four gauges from 0.025 mm to 0.075 mm. Laser cutting produces clean edges and is suitable for complex custom profiles and component-footprint shapes. The film can be supplied in flat sheet, coil, or disc format, and its dimensional stability under compression makes it suitable for both prototype and high-volume production thermal interface assembly.