Aluminium <-> copper

[yellow]

Do I get this right?

because of the capabilities of the copper, when using in for the led mounting plate / thermal plate, the heat from the led "needs" a longer time to heat up the material
but there is no negative point concerning to pass the heat further to the light housing ... ?

So except for cost and more weight copper is "superior" to aluminium. (?)


Would it make any sense to use brass instead of copper (oxidation, or such ?)?

 

[gadget_lover]

There is some loss of heat transfer efficiency each time the material changes. This means that in most cases the transition from a 1/4 thick copper heatsink to a 1/4 inch aluminum one of the same area will not move the heat away as efficiently as if it was made of one material. The junction between the two surfaces is not perfect so there will always be some increased resistance to heat flow.

Heat is energy. The heat HAS to go somewhere, so passing it to the body lets it escape to the air. If it is not passed to the air it will build up until the LED internals break down.

Dan

 

[Yoda4561]

For the most part brass in inferior in terms of heat conductivity to copper and most aluminum alloys. There are special grades of brass that do conduct heat almost as well, but the primary reason to use brass is that it's much easier to machine than aluminum/copper and you can solder directly to it, which is pretty difficult to do right with aluminum.