A true cold welding for LED thermal junction

[clemence]

Is that possible to electrolytic weld the led thermal base directly onto copper or aluminum heatsink using similar electroplating technique? That way we don't have to use those solder/epoxy, plus, definitely better heat transfer.

 

[qwertyydude]

The best method to "weld" an led to a heatsink is simply soldering, it creates a solid metal contact patch that transfers heat very effectively. Any non-metal joining method would not conduct heat better than a solid metal solder joint.

 

[clemence]

The best method to "weld" an led to a heatsink is simply soldering, it creates a solid metal contact patch that transfers heat very effectively. Any non-metal joining method would not conduct heat better than a solid metal solder joint.

You've got me wrong dude. I didn't mean to fill the gap with electrolyte. If it's doable then the gap would be filled with pure copper and perfectly bonded/welded to both side (the LED thermal pad and the heatsink).

The idea came up when I accidentally welded the copper and the negative wire. I tried some old school electroplating chemistry experiment. It wasn't that strong though...

 

[qwertyydude]

It is entirely possible to do such a bond. Not exactly environmentally friendly though. Most plating would not properly join two materials but to achieve metal bonding without heating to a melting point you could use a silver-mercury amalgam. It will bond metal to metal when pressed while still in it's paste form. But then again it's still easier to solder.

 

[clemence]

I was thinking to use silver as the joining metal but the silver plating is too hazardous (I don't want to use cyanide acid). Copper is a better option since it can be plated using relative safer acidic technique.
Yes, it's not easy but the thermal conductivity difference is too tempting to try. Do you know the thermal conductivity of silver amalgam?