Plate Heatsink Size

Hi all,

I`m working on a project with high powered LEDs. In the thermal design I`m have this problem. I find a value of the maximum Case-to-Ambient Thermal Resistance. But I don`t know how I can use this value to find the dimensions of a square plate heat sink (aluminium). Does someone here know how to calculate this?

Thanks in advance.

Bruno

Here is a **broken link removed**.

For a quick and dirty solution you can use 50 divided by the square root of the area in CM. So 6.25 square cm = 20 degree C per watt. Add this to junction to case from the data sheet. Leave some safety margin for mounting etc.

Thank you guys. It helped me a lot.