Sinkpad question for those that have them or know about them.I noticed on the back of the boards that there's a recess/chamfer,is there a reason that this is not flush with the rest of the board.It seems to me,you would want this part in direct contact with the heatsink.Should this recess be filled with heatsink compound?I may be over thinking this,but I want to make sure I get optimal performance from these.
It’s solid copper that is pressed in and is the center pad under the led. Although the edges are recessed, the rest is flush with the bottom. Filling with solder will help a lot more than filling with AA. The biggest thing about them is the removal of the dielectric layer between the pad and metal core that is present on non Sinkpad pcb’s.
Thanks,that helps me understand better,I can't wait to start builds with these.
What is this? It keeps cropping up. Dielectric layer.
That recessed area is the most critical place needed for thermal transfer, yet there's the hole . It needs to be filled with thermal paste or better, with tin. Make sure you don't let the tin become a blob that actually slightly raises the hole board up.
When Sinkpads first hit BLF, that was my initial thought: that hole has to go. Either fill it with copper and sand it flush or sand the back of the Sinkpad until its flat.
But thats all pretty much nonsense. While the heat is generated mainly in the center of the LED, it spreads all over the star instantly, so there is enough contact area to the pill or heatsink.
TL;DR: Dont worry about it, it doesnt matter.
And, the area where the heat is generated (center pad on the LED) is dwarfed by the area of the Sinkpad contact to whatever you put it on. It will work nearly as well even on 'hollow' pills where the star only has contact around the outside edge. And that's the whole reason for using the copper in the first place.
It’s a non conductive layer between the copper traces and the metal core of the pcb.
How good are the aluminium sinkpads? I have some and was wondering if they are worth the trouble over a regular board?
Thanks for the input on these,I planned on lapping both points of contact as well.The recess was actually bothering me and I didn't want to move forward without understanding the function of it.Now the wait for some nice high binned XML-2's.