Eli5: How do heat sinks work?

Question

Curious how they work. Why do they look like lots of layers of fins.

In: 6

Answer 1

It’s a type of heat exchanger. It’s made of something thermally conductive (you see aluminium pretty often) which absorbs heat from what you’re trying to cool, by conduction.

Then, the heat is transferred via convection to whatever fluid you’re using. Often you’ll see air used with a fan forcing it over the fins, but you can also use a liquid to do the same.