LED Thermal Management
The term LED means Light Emitting Diode and is perhaps one of the biggest sensations in the world of lighting. LED based on the nature of its functioning has many inherent advantages. It has significantly smaller footprint, higher efficiencies and lasts a long time. It therefore goes without saying that with the rising popularity of the LEDs, the challenges of designing with them is growing, especially in areas of LED thermal management. In this context one of the best places to start with would be thermal management within a printed circuit board or MCPCB.
Thermal Management In MCPCB
If you are using LED power, there are chances that you would encounter problem at or above 80 watts. For example if you are considering application like the street lighting which might require up to 150 watts per lamp, led thermal resistance at such high power point would be a cardinal concern.
The point to remember is here would be that thermal connection between the LED and the MCPCB is established with a help of a thermal via and designing them at varied planes could reduce the overall system temperature by 10°C.
Not just that research has indicated to achieve the right kind thermal management, MCPCBs can be created using a wide range of heat-dissipating materials without changing the LED component. From copper which offers better thermal conductivity to aluminum which is cheaper to specialized MCPCBs using coated steel, ceramics or many other options, the range is unbelievably long.
To address the LED thermal resistance issues and achieve optimum thermal management using LED, external heat sinks can also be used. This facilitates dissipation of exceptionally large amount of heat. Infact on an average MCPCBs have several different shapes and degrees of heat dissipation profile. However the most challenging ones are no doubt the types in which the LED applications have to be stored in airtight enclosure to protect from the environment around. Thermal management in this case could be anything from air-to-air heat exchangers to using internal fans to even heat transfer via a series of conduction and convection alternatives.
Conclusion: Digital Control
One fundamental approach to address the LED thermal resistance issue and effective thermal management via LED can be achieved through relying on digital control. One brilliant example of that could be the use of thermistor near the LED. This will enable tracking temperature in a specific part of the MCPCB that is mounting the LED. As a result this will not just monitor temperature but can also incrementally cut down voltage supply of the temperature exceeds a given limit. Moreover digital control can also optimize LED efficiency and thereby the overall energy usage and effective thermal management.