Re: [Work in progess] Burnins Avalon Chip to mining board service
he actually responded to this issue a few pages back. Shouldn't take too much time to find & he explains why he did this
OK find this:
"Exposing the copper on the bottom will increase the thermal coupling but i want to keep the heat sinks isolated.
(Important for water cooling, electrical corrosion)"
Well it makes difficult to solder heatsink on painted surface and using stripper will remove all paint. Not good. Electrical corrosion blah. If use same ground no broblem or use non conducting coolant.
You don't solder on heatsinks, you use thermal pads or paste.. If you could solder them on, then almost by definition they aren't good heatsinks.