Heat Transfer and LEDs; Why is it important?

23 Jan 2026 Updated at 23 Jan 2026

LEDs generate a lot of heat as a byproduct, and to ensure optimal performance and longevity they require this heat to be transferred away from the electrical components such as printed circuit boards.

What is heat dissipation?

Thermal (heat) dissipation is the management and removal of excess thermal energy from heat-generating components to ensure stable operation, performance, and long-term reliability. Thermal interface materials (TIMs) are used to minimise interfacial thermal resistance by filling air gaps and surface irregularities between PCBs, LED dies, or semiconductor packages and a heat sink or chassis.

By improving thermal conductivity and enabling efficient heat transfer via conduction, TIMs help maintain junction temperatures within specified limits, reducing the risk of thermal degradation, performance loss, or premature component failure.

Why is bond line thickness important for heat transfer?

Reducing bond line thickness decreases the thermal conduction path between the heat source and the heat sink. A thinner bond line results in lower thermal resistance, improving heat transfer efficiency and enabling more effective dissipation of thermal energy away from the source.

Why is heat dissipation important in LEDs?

LEDs are semiconductors which will degrade when they get too hot, without effective cooling systems they will eventually fail. Effects of inefficient LED heat transfer include:

Reduced light output
Colour shifts
Shortened driver and LED lifespan
LED failure and permanent chip damage

How can gap fillers be used for effective heat dissipation?

Air is the enemy of thermal management

Gap fillers are one of the most effective ways of improving thermal management in LED applications. Even tiny air gaps can impede heat flow between an LED module or PCB and heat sink, dramatically increasing thermal resistance.

Gap fillers are dispensed to eliminate air gaps, conforming to uneven surfaces and working with heat sinks to create a heat path. They are an ideal LED cooling solution, stabilising LED temperatures, and extending luminaire lifetime.

Other materials which can be used for heat transfer include thermally conductive adhesives and thermal interface materials.

Where can you use gap filler materials in LED applications?

Gap fillers can be used in LED Module heat sink interface, Driver & Power Supply Components, and LED Strips in Extrusions.

Products to Consider:

Momentive RTV160 Electronic Silicone

3M TC2810 Thermally Conductive Epoxy Adhesive

TECHSiL RTV1084G Thermally Conductive Rubber

TECHSiL TIM11123 Thermally Conductive RTV Silicone