Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: Heat Flow and Heatsinks

Learn more physics!

Most recent answer: 10/22/2007
Q:
Do diffrent metals have a diffrent rate at which they transfer heat to their surrounding air? Not just conduct heat through the metal. I am mainly refering to heatsinks for various electronics.
- mike
A:
Mike,

There are a few more concepts that you may find useful in thinking about this. The three things that are the most important for a good heat-sink are:

1) It should have a good thermal contact to the device its attached to. There are special compounds that are good thermal conductors that can be put between the chip and the heat-sink that help this, and it is also important to make sure the heat-sink is held tightly against the chip.

2) It should be a good enough conductor of heat. This is not too hard to do...many common metals, like aluminum, work well.

3) It should be able to efficiently shed the heat that it absorbs to the surrounding environment. This often requires careful engineering. Good heat sinks will often have lots of "fins" to increase their surface area, allowing the heat-sink to efficiently radiate the energy that it is absorbing from the electronics. It is also important that there be some air flowing around the heat-sink so that convective heat-transfer will be more efficient. Heat sinks on modern high-speed CPU chips often have a fan attached right to the heat-sink itself.

Mats

(published on 10/22/2007)

Follow-up on this answer.