EDN has a nice article write up on how to decide when it’s worth paying for the lower thermal impedance? Margery Conner, who covers LEDs, solid-state lighting, alternate energy sources, and sensors on her beat, notes the following in her trailer lead-in:
The thermal characteristics of the metal-clad pc-board (MCPCB) in LED lighting is becoming increasingly important. Back when LED packages had fairly poor thermal impedance numbers, the thermal characteristics of the MCPCB weren’t so important. But today’s packaged LEDs have increasingly good (low) thermal impedance numbers, and as the package’s thermal impedance drops, the thermal impedance of the MCPCB’s dielectric plays a bigger role.
The answer? Well according to Berquist’s Steve Taylor, quoted in EDN’s article, is to “making a quick calculation to determine the LED package’s normalized thermal impedance”. But that’s just the start. Go have a read for yourself to read the rest, it’s a great take and solution on good design for LED thermal management; Here’s the link, “Normalize LED package thermal impedance for optimum thermal design“