LED lighting

LED lighting, as a new generation of green light source, has gained widespread application in road lighting, commercial lighting, industrial lighting, and automotive lighting due to its advantages of high luminous efficacy, low energy consumption, and long service life. However, LED chips are fundamentally semiconductor light-emitting devices, and their electrical energy utilisation is not 100%. Approximately 60% to 70% of the input energy is converted into heat. Should this heat fail to dissipate promptly and efficiently, it leads to elevated junction temperatures, subsequently causing diminished luminous efficacy, accelerated light decay, colour temperature drift, and even complete light source failure. These issues severely impact luminaire lifespan and user experience. Consequently, the thermal management system constitutes a critical element in LED luminaire design, directly determining product performance and reliability.

Key challenges in LED lighting thermal management include: the compact size and high thermal power density of LED chips, which concentrate heat with rapid transient responses, demanding swift thermal extraction; constrained luminaire dimensions—particularly for indoor lighting and automotive applications—limiting available heat sink space; outdoor luminaires must simultaneously meet waterproofing, dustproofing, corrosion resistance, and UV protection requirements, further complicating design. Take road lighting as an example: luminaires must operate stably over extended periods within temperatures ranging from -40°C to +50°C, demanding heat sinks that combine high thermal conductivity with exceptional weather resistance.

Different thermal management solutions can be selected for luminaires across varying power ranges. Low-power LED bulbs may employ a simple aluminium substrate with stamped heat sink fins, offering cost-effectiveness; Medium-to-high power downlights, industrial/mine lights, and floodlights predominantly utilise extruded or cold-forged heat sinks to achieve greater surface area and lower thermal resistance. For high-power streetlights or stage lighting, heat pipe or heat spreader plate technologies are often integrated to rapidly distribute heat to the fin array, dissipating it via natural convection or forced air cooling. Skived Fin heat sinks, with their high fin density and superior thermal efficiency, are suited for demanding thermal performance scenarios. Die-cast heat sinks, integrated as a single unit with the luminaire body, balance aesthetics and structural integrity, making them a common choice for outdoor lighting.

Surface treatment is equally critical. Anodizing, sandblasting, or powder coating not only enhance visual appeal but significantly improve corrosion resistance, extending outdoor service life. For highly corrosive environments like coastal areas or chemical plants, hard anodizing or fluorocarbon coating processes are recommended. Design considerations must also ensure unobstructed convection pathways, minimize air resistance, and prevent dust accumulation that degrades thermal performance.