to the United States 
For most LED module installations, the best way to attach a module to a heatsink or cooling surface is double-sided thermal tape. Thermal tape provides reliable thermal contact, is straightforward to apply, and avoids the mechanical stresses that cause long-term reliability problems.
Why we don’t recommend mechanical fasteners
Screws and other mechanical fasteners can warp or twist the module base, even if the deflection is too small to see. That flexing puts stress on the solder joints connecting the LED to the substrate, and cracked or fatigued solder joints disrupt the thermal path from the LED die down to the heatsink.
Once that thermal path is compromised, junction temperatures rise, light output drops, and the module fails well short of its rated life.
Because LED performance depends on effective heat transfer, any mounting method that risks the solder joint is not worth the trade.
High-vibration applications
If the module will experience heavy mechanical vibration in service, such as in a vehicle, machinery, or industrial environment, a thermally conductive epoxy like Arctic Silver bonds more aggressively than thermal tape.
Keep in mind that epoxy is permanent. Once cured, the module cannot be removed from the heatsink without damaging one or both parts, so commit to the placement before you apply it.
Surface preparation
Whichever method you choose, the cooling surface must be flat, clean, and free of oils, dust, or oxidation. Both thermal tape and thermal epoxy depend on intimate contact between the module base and the heatsink. A rough or contaminated surface leaves microscopic air gaps, and air is an excellent thermal insulator.
Wiping the heatsink with isopropyl alcohol before assembly is good practice. Applying firm pressure between the LED module and cooling surface for at least 10 seconds will ensure a thermally sound joint.
