The biggest technical challenge for LED lighting fixtures at present is heat dissipation. Poor heat dissipation has led to LED driver power supply and electrolytic capacitors becoming the shortcomings for the further development of LED lighting fixtures, and the reason for premature aging of LED light sources.
In the lighting scheme using LV LED light source, due to the working state of LED light source at low voltage (VF=3.2V) and high current (IF=300-700mA), it generates a lot of heat. Traditional lighting fixtures have limited space, and it is difficult for small area heat sinks to quickly dissipate heat. Despite using various heat dissipation solutions, the results were unsatisfactory and became an unsolvable problem for LED lighting fixtures. We are always striving to find simple and easy-to-use heat dissipation materials with good thermal conductivity and low cost.
At present, when LED light sources are powered on, about 30% of the electrical energy is converted into light energy, and the rest is converted into heat energy. Therefore, exporting so much thermal energy as soon as possible is a key technology in the structural design of LED lamps. Thermal energy needs to be dissipated through thermal conduction, convection, and radiation. Only by exporting heat as soon as possible can the cavity temperature inside the LED lamp be effectively reduced, the power supply be protected from working in a prolonged high-temperature environment, and the premature aging of the LED light source caused by long-term high-temperature operation be avoided.

The heat dissipation pathway of LED lighting fixtures
Because LED light sources themselves do not have infrared or ultraviolet radiation, they do not have radiation heat dissipation function. The heat dissipation path of LED lighting fixtures can only be exported through a heat sink closely combined with the LED bead board. The radiator must have the functions of heat conduction, heat convection, and heat radiation.
Any radiator, besides being able to quickly transfer heat from the heat source to the surface of the radiator, mainly relies on convection and radiation to dissipate heat into the air. Thermal conduction only solves the pathway of heat transfer, while thermal convection is the main function of heat sinks. The heat dissipation performance is mainly determined by the heat dissipation area, shape, and natural convection intensity, and thermal radiation is only an auxiliary function.
Generally speaking, if the distance from the heat source to the surface of the heat sink is less than 5mm, as long as the thermal conductivity of the material is greater than 5, its heat can be exported, and the rest of the heat dissipation must be dominated by thermal convection.
Most LED lighting sources still use LED beads with low voltage (VF=3.2V) and high current (IF=200-700mA). Due to the high heat generated during operation, aluminum alloys with high thermal conductivity must be used. There are usually die cast aluminum radiators, extruded aluminum radiators, and stamped aluminum radiators. Die cast aluminum radiator is a technology of pressure casting parts, in which liquid zinc copper aluminum alloy is poured into the feeding port of the die-casting machine, and then die cast by the die-casting machine to produce a radiator with a shape defined by a pre designed mold.

Die cast aluminum radiator
The production cost is controllable, but the heat dissipation wings cannot be made thin, making it difficult to increase the heat dissipation area. The commonly used die-casting materials for LED lamp heat sinks are ADC10 and ADC12.

Squeezed aluminum radiator
Squeezing liquid aluminum into shape through a fixed mold, and then cutting the bar into the desired shape of a heat sink through machining, incurs higher processing costs in the later stages. The heat dissipation wings can be made very thin, with the maximum expansion of the heat dissipation area. When the heat dissipation wings work, they automatically form air convection to diffuse heat, and the heat dissipation effect is good. The commonly used materials are AL6061 and AL6063.

Stamped aluminum radiator
It is achieved by stamping and pulling steel and aluminum alloy plates with punching machines and molds to form cup shaped radiators. The stamped radiators have smooth inner and outer edges, but limited heat dissipation area due to the lack of wings. The commonly used aluminum alloy materials are 5052, 6061, and 6063. Stamping parts have low quality and high material utilization, making it a low-cost solution.
The thermal conductivity of aluminum alloy radiators is ideal and suitable for isolated switch constant current power supplies. For non isolated switch constant current power supplies, it is necessary to isolate AC and DC, high and low voltage power supplies through the structural design of the lighting fixtures in order to pass CE or UL certification.

Plastic coated aluminum radiator
It is a heat sink with a heat-conducting plastic shell and aluminum core. Thermal conductive plastic and aluminum heat dissipation core are molded in one go on an injection molding machine, and the aluminum heat dissipation core is used as an embedded part, which requires mechanical processing in advance. The heat of LED beads is quickly conducted to the thermal conductive plastic through the aluminum heat dissipation core. The thermal conductive plastic uses its multiple wings to form air convection heat dissipation and radiates some of the heat on its surface.
Plastic wrapped aluminum radiators generally use the original colors of thermal conductive plastic, white and black. Black plastic wrapped aluminum radiators have better radiation heat dissipation effects. Thermal conductive plastic is a type of thermoplastic material that is easy to shape through injection molding due to its fluidity, density, toughness, and strength. It has excellent resistance to thermal shock cycles and excellent insulation performance. Thermal conductive plastics have a higher radiation coefficient than ordinary metal materials.
The density of thermally conductive plastic is 40% lower than that of die cast aluminum and ceramics. For radiators of the same shape, the weight of plastic coated aluminum can be reduced by nearly one-third; Compared with all aluminum radiators, it has lower processing costs, shorter processing cycles, and lower processing temperatures; The finished product is not fragile; Customers can provide their own injection molding machines for differentiated appearance design and production of lighting fixtures. The plastic wrapped aluminum radiator has good insulation performance and is easy to pass safety regulations.

High thermal conductivity plastic radiator
High thermal conductivity plastic radiators have been developing rapidly recently. High thermal conductivity plastic radiators are a type of all plastic radiator with a thermal conductivity dozens of times higher than ordinary plastics, reaching 2-9w/mk, and have excellent thermal conductivity and radiation capabilities; A new type of insulation and heat dissipation material that can be applied to various power lamps, and can be widely used in various LED lamps ranging from 1W to 200W.
The high thermal conductivity plastic can withstand AC 6000V and is suitable for using non isolated switch constant current power supply and high voltage linear constant current power supply of HVLED. Make these LED lighting fixtures easy to pass strict safety inspections such as CE, TUV, UL, etc. HVLED operates in a high voltage (VF=35-280VDC) and low current (IF=20-60mA) state, which reduces the heat generation of the HVLED bead board. High thermal conductivity plastic radiators can be made using traditional injection molding or extrusion machines.
Once formed, the finished product has high smoothness. Significantly improving productivity, with high flexibility in styling design, allowing designers to fully utilize their design concepts. The high thermal conductivity plastic radiator is made of PLA (corn starch) polymerization, which is fully degradable, residue free, and free of chemical pollution. The production process has no heavy metal pollution, no sewage, and no exhaust gas, meeting global environmental requirements.
The PLA molecules inside the high thermal conductivity plastic heat sink are densely packed with nanoscale metal ions, which can move rapidly at high temperatures and increase thermal radiation energy. Its vitality is superior to that of metal material heat dissipation bodies. The high thermal conductivity plastic heat sink is resistant to high temperatures and does not break or deform for five hours at 150 ℃. When applied with a high-voltage linear constant current IC drive solution, it does not require electrolytic capacitors or large volume inductors, greatly improving the lifespan of LED lights. It is a non isolated power supply solution with high efficiency and low cost. Especially suitable for the application of fluorescent tubes and high-power mining lamps.
High thermal conductivity plastic radiators can be designed with many precise heat dissipation wings, which can be made very thin to maximize the expansion of heat dissipation area. When the heat dissipation wings work, they automatically form air convection to diffuse heat, resulting in better heat dissipation effect. The heat of LED beads is directly transferred to the heat dissipation wing through high thermal conductivity plastic, and quickly dissipated through air convection and surface radiation.
High thermal conductivity plastic radiators have a lighter density than aluminum. The density of aluminum is 2700kg/m3, while the density of plastic is 1420kg/m3, which is almost half of aluminum. Therefore, for radiators of the same shape, the weight of plastic radiators is only 1/2 of aluminum. And the processing is simple, and its molding cycle can be shortened by 20-50%, which also reduces the cost of power.