aluminum heatsink anodizing

Sil-pads are so bad, it doesn't matter how you finish the heat sink.

John

I would use a level 3 hard anodize for electrical resistance, and use silver filled IC chip bonding epoxy to nail the part to it. Less serviceable, but passes the thermals as best as can be done while maintaining no electrical contact.

"Jamie Morken"

Use thin, mica insulators with a smear of white (usually zinc oxide loaded ) thermal grease each side - not only does this conduct heat much better but mica will not *compress* over time like sil-pads do and result in your mounting bolts becoming so loose you can rotate them with your fingers.

This loss of crucial pressure ruins the performance of the heatsinking.

That said, a black anodised heatsink radiates IR energy much better than a silvery one - so it will generally be a few degrees cooler.

.... Phil