Best way to solder Rebels on metal plates?

[x2x3x2]

What would be the best way to solder these little things onto a flas metal face? Say for example a cpu heatsink or just a plain aluminum plate.

I was gonna try to do an array of Rebels on an old cpu heatsink, but those contacts are so small...

Alternatively, are these being sold pre mounted on more work friendly pcbs?

 

[moon lander]

where are the contacts on those things anyway? the ones on the top are coated with something. are there also contacts on the bottom? anyhow, looks like Brlux is already soldering these with regular tools. he explained it in this thread http://www.candlepowerforums.com/vb/showthread.php?t=159082&page=4

 

[shinbone]

Solder pads are on the bottom of the ceramic heatsink; the large isolated pad is below the LED, the Anode/Cathode pads sit side by side on the outer tab of the ceramic plate. Lumileds website has some .pdf files with engineering drawings of the whole layout along with dimensions for exact detail.

 

[greg_in_canada]

I don't think you can solder to aluminum. Normal circuit boards are copper, and possible coated with tin/lead solder.

Greg