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  • Wuxi Kinglux Glass Lens Co.Ltd
  • ADD:No.286,Changjiang North Rd,New Dist,Wuxi,JS prov,China
  • Tel: 86-510-66759801
  • Fax: 86-510-84602998
  • Mobile phone: 86-18168862789
  • E-mail: ledglasslens@163.com
  • Contact person: Huimin Zhang
    Mar 28, 2018

    Heat sinks are an important part of LED lighting because they provide the path for heat to travel from the LED light source to outside elements. Heat sinks are able to dissipate power in three ways: conduction (heat transfer from a solid to a solid), convection (heat transfer from a solid to a moving fluid, air in most cases), or radiation (heat transfer from two bodies at different temperatures through thermal radiation).

    MCPCBs: Aiding the heat sink

    Before diving into heat sinks you must know that when you purchase LEDs on our metal core printed circuit board LED stars this is already taking a good step to better thermal control. LEDs come in reels as bare emitters that are encapsulated in a transparent resin, which tends to be a poor thermal conductor, so when we mount them on an aluminum base it acts as a heat spreader and is an integral part of the circuit board that aids in thermal conductivity.

    Adhesive: Thermally Conductive

    Now in mounting our star boards to the heat sinks it is best to use a thermally conductive material to further take steps in optimal thermal performance. We recommend this Arctic Silver epoxy, it’s what we use here in the craft shop when we build all the LED kits we offer. We also have a very quick option in our HexaTherm Tape which is essentially just thermally conductive double sided tape in the exact shape of our LED star boards. The HexaTherm isn’t as thermally conductive as the epoxy but it will still do the trick. LEDSupply offers HexaTherm in 1-up and 3-up Star board tape sizes.

    Heat Sink Material

    The thermal conductivity of the heat sink material directly affects how efficiently the heat dissipates through conduction. Copper is the best but because of its price point, aluminum is used more widely and is what the majority of the heat sinks we offer here at LEDSupply are. Thermoplastics, like our composite LED heat sink, can be used for smaller LEDs with lower heat dissipation requirements. The use of thermoplastics can be very useful as they can be molded in more shapes and are much more light weight.

    led-heatsink-finned-102-1489_svHeat Sink Shape

    The thermal transfer takes place at the surface of the heat sink. That is why the best heat sinks have a large surface area. This can be achieved by straight up increasing the size of the heat sink, or by the use of fins. Finned heat sinks help as they provide many more surfaces for heat to transfer from. Whereas fins help, there still needs to be enough space in between fins for air to move through to generate a difference in temperature between the fins and the air. When fins are made too close together, the air in between wouldn’t cool and would become almost the same temperature as the fins which would stop thermal transfer all together. So more fins doesn’t automatically mean better cooling, you need well spaced fins.

    Heat Sink Finish

    The surface of your heat sink actually has a direct effect on thermal conductivity as well. A painted surface will actually work better than a bright, unpainted one. This also is the same for anodizing and etching heat sinks which will decrease the thermal resistance and make for an overall better heat sink.