Thermal Interface Materials

Thermal interface materials (TIMs) fill microscopic air gaps between heat-generating components and heatsinks or enclosures, providing a low-resistance thermal path. We stock silicone gap pads, phase-change films, electrically isolating pads, and graphite-enhanced sheets for electronics cooling, power conversion, LED assemblies, and battery thermal management.

At a Glance

Temperature Range

Form-dependent: silicone gap pads -60 °C to +200 °C continuous; phase-change films -40 °C to +125 °C; non-silicone PU isolating pads -40 °C to +125 °C

Thickness Range

0.1 mm to 5.0 mm

Available Forms

SheetDie-cut padPre-cut custom shapeRoll (thin films)

Colours

Blue (standard silicone gap pad)Grey (filled compounds)White (isolating grades)Dark grey/black (graphite-enhanced)
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Technical Properties

Typical values across stocked grades. Specific grade data sheets available on request.

Thermal Conductivity1.0–12.0 W/m·K (grade dependent)
Operating TemperatureForm-dependent. Silicone gap pads: -60 °C to +200 °C continuous. Phase-change films: -40 °C to +125 °C. Non-silicone PU isolating pads: -40 °C to +125 °C. Graphite TIMs: binder-limited
Breakdown Voltage3–15 kV (isolating grades)
Thickness Range0.1–5.0 mm
HardnessShore 00 20–60 (gap pads); N/A (films)
Specific Gravity1.5–3.5 (filler dependent)
Thermal Impedance0.05–0.8 °C·in²/W (at rated pressure)
Outgassing (ASTM E595)< 1.0% TML (low-outgassing grades available)

Physical Characteristics

Density

1.5–3.5 g/cm³

Thermal Conductivity

1.0–12.0 W/m·K (grade dependent)

Dielectric Strength

3–15 kV (isolating grades)

Chemical Resistance

Resistant To

  • Thermal cycling and ageing
  • Most electronics cleaning solvents (IPA, flux removers)
  • Silicone oils (silicone-based grades)
  • Moisture and humidity

Limited Resistance

  • Prolonged hydrocarbon solvent immersion
  • Strong acids and alkalis

Not Recommended

  • Direct contact with fuels or aggressive solvents (non-silicone grades)
  • Continuous outdoor UV exposure without enclosure

Environmental Ratings

Flame Rating

UL 94 V-0 (most grades)

Standards & Certifications

Standards Compliance

ASTM D5470-17(2024) (thermal transmission of thin thermally-conductive solid electrical insulation materials)ASTM E1530 (thermal conductivity)ASTM E595 (outgassing, NASA specification — TML <1.0%)ASTM D149 (dielectric strength — AC test method)UL 94 V-0 (flammability; most grades)IEC 60243-1 (dielectric strength, AC)RoHS 2015/863 compliant

Certifications

UL 94 V-0 (selected grades)RoHS 2011/65/EU

Common Applications

  • Power electronics and IGBT module cooling
  • LED lighting heatsink interfaces
  • EV battery cell-to-pack thermal management
  • Telecommunications equipment and base stations
  • Server and data centre processor cooling
  • Industrial motor drive heat dissipation
  • Medical device electronics enclosures
  • Automotive ECU and inverter assemblies

Not Recommended For

  • Silicone-based TIMs can cause contamination in optical or certain coating processes; use silicone-free alternatives where silicone migration is a concern
  • Phase-change materials require initial activation above their transition temperature, so performance improves after the first thermal cycle
  • Graphite-enhanced pads are electrically conductive. Do not use where electrical isolation between component and heatsink is required
  • Softer gap pads (Shore 00 20) may squeeze out under excessive clamping pressure, so follow manufacturer torque guidelines
  • Thermal conductivity values are measured under controlled lab conditions; actual performance depends on surface flatness, contact pressure, and joint geometry

Available Grades

Silicone Thermal Gap Pad

Soft, conformable silicone elastomer filled with ceramic or boron nitride particles. Thermal conductivity typically 1.5–6.0 W/m·K. Compresses to fill gaps of 0.5–5.0 mm between uneven surfaces. The most common general-purpose TIM for electronics assemblies.

Phase-Change TIM

Thin film that transitions from solid to semi-liquid at operating temperature (typically 45–55 °C), wetting both surfaces to minimise thermal impedance. Extremely low bond-line thickness after activation. Suited to high-performance processor and GPU applications.

Electrically Isolating Thermal Pad

Ceramic-filled silicone or silicone-free pad providing both thermal conductivity (1.0–5.0 W/m·K) and high dielectric strength (5–15 kV). Used where the heat path must also serve as an electrical barrier — power transistors, MOSFETs, and voltage regulators mounted to grounded heatsinks.

Graphite-Enhanced TIM Pad

Natural or synthetic graphite sheet, sometimes laminated with a polymer binder, offering very high in-plane thermal conductivity: 200–1500 W/m·K (Panasonic PGS, T-Global T68, Henkel APG); annealed pyrolytic graphite up to ~1700 W/m·K. Through-plane conductivity is much lower at 1–10 W/m·K — this anisotropy is the engineering point. Electrically conductive. Used in high-power applications where heat must spread laterally before transferring to the heatsink.

Speciality TIM Compound Sheets

Application-specific formulations including silicone-free pads for optical environments, low-outgassing variants for aerospace, and high-temperature grades for power generation electronics. Properties tailored to the end-use requirements.

Need Thermal Interface Materials?

We supply thermal interface materials in sheet, roll, and custom die-cut forms. Contact our team for pricing, data sheets, or technical assistance.

Disclaimer

This resource is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.