Even when a heat sink and metal enclosure look fully seated after assembly, the actual contact surface can still carry microscopic gaps from surface roughness, tolerance stack-up, and dissimilar-material bonding. Those gaps add extra resistance right where the thermal path needs to stay continuous, which is why interface management matters as much as the heat sink itself in communications gear, LED modules, and automotive electronics.
Aluminum Foil Thermal Conductive Tape (H-TT-AL) is a bonding-type thermal material with a high-quality aluminum foil facestock and a thermal adhesive layer. The official product page lists a thermal conductivity of 0.45 W/(m·°C), 6KV dielectric withstand voltage, and a -30°C to 150°C service temperature range. This kind of thin aluminum tape is used to form a continuous, mechanically fixed thermal path between metal parts, or between metal and plastic substrates.
How Interface Contact Affects the Thermal Path
When two surfaces are bonded with a tape, the effective conduction-path length includes the tape’s own total thickness as well as how fully the surfaces mate. The official specification lists H-TT-AL’s total thickness as 0.100 ± 0.005 mm (0.060 ± 0.003 mm aluminum foil facestock plus 0.040 ± 0.003 mm adhesive), paired with 0.6 kg/25mm circular initial tack and 1.5 kg/25mm adhesion to steel, intended to keep the bond in place over time so the thermal path is not interrupted by lifting or delamination.
Engineering Formula: A One-Dimensional View of Thickness and the Thermal Path
Q = (k × A / L) × ΔT is the Fourier one-dimensional steady-state conduction model. Q is the heat-transfer rate (W), k is the material’s thermal conductivity (W/(m·K)), A is the effective area normal to heat flow (m²), L is the homogeneous conduction-path length (m), and ΔT is the temperature difference (K or °C). This relationship is described in MIT OpenCourseWare’s Introduction to Engineering Heat Transfer course notes. The model applies as a conceptual estimate for homogeneous material, approximately one-dimensional steady heat flow, and a roughly constant cross-sectional area; real bonded interfaces are also affected by surface roughness, bonding pressure, adhesive-thickness uniformity, and the temperature dependence of k, so it is not a measured specification or performance guarantee for this product. The formula does show that, all else equal, a shorter path length L — such as a thinner tape — helps lower the overall thermal resistance.
Design Points
- The thin 0.100 ± 0.005 mm total thickness helps keep the conduction-path length L short.
- A thermal conductivity of 0.45 W/(m·°C) combined with an aluminum foil facestock suits bonding between metal parts, or between metal and plastic substrates.
- 6KV dielectric withstand voltage paired with a -30°C to 150°C service range addresses common electrical-safety and thermal-cycling requirements.
- Circular initial tack of 0.6 kg/25mm and steel adhesion of 1.5 kg/25mm are reference points for evaluating long-term bond reliability.
- The metal aluminum facestock can also provide a degree of EMI shielding; the actual effect needs to be confirmed for the specific application.
Applications and Selection Notes
The official product page positions this series as a bonding material for electronics thermal management and shielding, suited to seam bonding and local repair of metal enclosures, heat sinks, or shielding layers in LED modules, notebooks, and communications equipment. When selecting, confirm the bonding-surface materials, tolerances, and the required voltage-withstand rating first, then validate thermal resistance and bond reliability with real module testing.
If you are evaluating aluminum foil thermal tape for an enclosure or heat-sink interface, check the published specifications on the Aluminum Foil Thermal Conductive Tape product page and arrange samples for system-level validation.
