Comparison and Analysis of Five Type Radiators for LED Lighting Fixtures

LED lighting is one of the biggest technical problems is the heat problem, poor heat led LED drive power, electrolytic capacitors have become the further development of LED lighting short board, LED light source premature decline reason.

Only the export of heat as soon as possible in order to effectively reduce the temperature inside the LED lamps in order to protect the power supply is not working in a lasting high temperature environment, in order to avoid the LED light source due to long-term high-temperature work and premature failure.

Because of the LED light source itself does not have infrared, ultraviolet, so the LED light source itself does not radiate heat dissipation, LED lighting cooling path can only be closely combined with the LED lamp beads to export the heat sink. Radiator must have heat conduction, convection, heat radiation function.

Any radiator, in addition to being able to quickly transfer heat from the heat source to the radiator surface, the most important thing is to rely on convection and radiation to heat to the air to go. Thermal conductivity solves only the way of heat transfer, and thermal convection is the main function of the radiator. The thermal performance is mainly determined by the capability of thermal area, shape and natural convection strength, and thermal radiation is only an auxiliary function. In general, if the heat is less than 5 mm from the heat source to the surface of the heat sink, then as long as the thermal conductivity of the material is greater than 5, the heat is dissipated and the remaining heat sink must be dominated by thermal convection.

Most LED lighting sources still use LED lamps with low voltage (VF = 3.2V) and high current (IF = 200-700mA). Due to high heat during operation, aluminum alloy with high thermal conductivity must be used. Die-cast aluminum radiators are usually available, extruded aluminum radiators, and stamped aluminum radiators. Die-cast aluminum radiator is a kind of technology of pressure casting parts. The liquid zinc-copper-aluminum alloy is poured into the inlet of the die-casting machine and is die-cast by the die-casting machine to cast the radiator with the shape limited by the design mold in advance.

The following is a comparison of five types of radiators.

Die-cast aluminum radiator

 

Production costs can be controlled, the radiator can not be thin, it is difficult to maximize the cooling area. LED lamp radiator die-casting materials commonly used ADC10 and ADC12.

Extruded aluminum radiator

 

Is the liquid aluminum through a fixed mold extrusion molding, and then the bar by machining cut into the shape of the radiator, the latter part of the higher processing costs. Extruded aluminum radiator shown in Figure 3. Cooling wings can do a lot of very thin, cooling area has been the largest expansion, the work of the cooling air convection automatically form heat, heat dissipation is better. Commonly used materials are AL6061 and AL6063.

Stamping aluminum radiator

 

Punch and die through the punch and die of aluminum, aluminum plate stamping, pull up, making it a cup-shaped radiator, heat sink inside and outside the stamping of the smooth, due to the limited space and heat dissipation. Commonly used aluminum alloy material is 5052,6061,6063. Stamping quality is very small, high material utilization, is a low-cost program.

Aluminum alloy heat sink is ideal, more suitable for isolation of the switch constant current power supply. For non-isolated switch constant current power supply, the need to do through the structural design of the lamp AC and DC, high voltage and low voltage power supply isolation, in order to pass CE or UL certification.

 

Plastic bag aluminum radiator

 

Is a heat-conducting plastic shell aluminum core radiator. Conductive plastic and aluminum heat sink in the injection molding machine on a molding, aluminum radiator made of embedded components, the need for pre-machining. The heat of the LED lamp bead is rapidly conducted to the heat conductive plastic through the aluminum heat dissipating core. The heat conductive plastic utilizes its multi-winged air convection to dissipate the heat, and uses the surface heat to radiate part of the heat.

Plastic-plastic aluminum radiator general use of the original color of thermal plastic white and black, plastic black plastic black aluminum radiator radiation cooling effect a little better. Thermoplastic A thermoplastic material that is easy to injection-mold in flow, density, toughness, and strength. It has good resistance to thermal shock cycles and excellent insulation properties. Thermal plastic radiation coefficient is superior to ordinary metal materials. Thermal plastic density 40% smaller than die-cast aluminum and ceramic, the same shape of the radiator, plastic-aluminum weight can be reduced by nearly one-third; with all-aluminum radiator compared to low processing costs, short processing cycles, low processing temperature; Finished product is not fragile; customer-owned injection molding machine can be differentiated lamp design and production. Plastic bag aluminum radiator insulation performance, easy to pass safety regulations.

High thermal conductivity plastic radiator

 

High thermal conductivity plastic heat sink recently developed rapidly, high thermal conductivity plastic heat sink a plastic heat sink, its thermal conductivity several times higher than ordinary plastic, up to 2-9w / mk, with excellent heat transfer, heat radiation ability Can be applied to a variety of power lamps of new insulation materials can be widely used in various types of 1W ~ 200W LED lamps.

High thermal conductivity plastic pressure level up to 6000V AC, suitable for non-isolated switch constant current power supply, HVLED high-voltage linear constant current power supply. Make these LED lighting easy to pass CE, TUV, UL and other strict safety testing. HVLED high voltage (VF = 35-280VDC), small current (IF = 20-60mA) working condition, HVLED lamp bead plate fever thus reduced. High thermal conductivity plastic radiator using the traditional injection molding, extruder can be. A molding, finished finish high. Greatly enhance the efficiency of students, modeling design flexibility, give full play to the designer's design philosophy. High thermal conductivity plastic radiator using PLA (corn starch) polymerization, full degradation, no residue, no chemical pollution, the production process without any heavy metal pollution, no sewage, no emissions, in line with global environmental requirements.

PLA elements within the highly conductive plastic heat sink are densely packed with nano-sized metal ions that can move rapidly at high temperatures and increase the heat radiation energy. Its vitality is superior to metal cooling body. High thermal conductivity plastic heat sink, 150 ℃ five hours without rupture, no deformation, with high-voltage linear constant current IC driver solution applications, without electrolytic capacitors and large-volume inductors, significantly improve the life of LED lights, non-isolated power supply scheme, high efficiency ,low cost. Particularly suitable for fluorescent tubes, high-power mining lamp applications.

High thermal conductivity plastic heat sink can design a lot of sophisticated cooling wings, the radiator wing can do a lot of thin, cooling area has been the largest expansion of the cooling wing work automatically form the air convection to spread heat, cooling effect is better. LED lamp beads of heat through the high thermal conductivity of plastic directly to the cooling wing, convection and surface radiation through the rapid cooling.

High thermal conductivity of plastic heat sink lighter than aluminum. The density of aluminum is 2700kg / m3, while the density of plastic is 1420kg / m3, almost half of aluminum, so the same shape of the radiator, plastic radiator weighs only 1/2 of aluminum. And simple processing, the molding cycle can be shortened 20-50%, which also reduces the cost of power.

 

www.luxledchina.com