Hello!
I have recently purchased a AC dimmer module I would like to connect to an Arduino board. The module came with the heat sink not mounted on the module. I have no experience with this so I am a bit unsure on how to mount it. Should it go on the TRIAC? how and where should I connect it?
The heat sink has not thermal pad or hole for connection.
I also saw on the product chat that the heat sink provided might be too small for this dimmer (it's AC 400V-4A but I am planning to use it with max 220V).
Thanks in advance for your help

 

It looks like a stick-on heatsink for a microprocessor. It's not going to do much good stuck to the plastic side of the triac.
A triac in a DPAK package is good for about 1Amp without a heatsink.