Thermal Interface Material

“TIM” is the gunk that improves heat transfer from the device you’re attempting to cool down, to the heat sink.

Also known as heat sink compound!

In the process of organising appropriate heat sinking for my 2.4 GHz, 3.4 GHZ, and 10 GHz PA units, I was looking at the Kuhne web site for ideas, and they offer Arctic silver 5, in the 3.5g syringe.

If it’s on the Kuhne web site, it must be good?

According to the manufacturer, Arctic Silver 5 claims to be “99.9% pure silver” in order to “maximize particle-to-particle contact area and thermal transfer.”
Unick Heat Transfer Compound
These compounds supposedly work better than the traditional hobbyist (cheap) heat sink compounds available at the likes of Jaycar.

When we look at the data sheet for the Unick product, we see the thermal conductivity is: 0.9W⁄mK

as5_big_blue1Kuhne claim the thermal conductivity for Arctic Silver 5 is: 9.0W/mK, although this figure was not found on the manufacturers web site at the time of looking.

The silver-based compound is (potentially) ten times more effective than the Unick product, but at a higher price point.

Click for full-size

Click for full-size

Now, some of PC gaming guys can get quite serious about their hardware!

Over at, they did a review of 80, yes 80, TIMs.

Looking at the results table, we see that the Arctic Silver 5 is rated as one of the best, being A+ rated. (Note the links to the lesser rated products B, C and D tables are to be found as well)
So yes, it appears to be very good at what it does.
How much to buy?
According to Arctic Silver:

Coverage Area:
A 3.5 gram syringe contains enough compound to cover at least 15 to 25 small CPU cores, or 6 to 10 large CPU cores, or 2 to 5 heat plates.
At a layer 0.003″ thick, the 3.5 gram syringe will cover approximately 16 square inches.

16 square inches equates to 100mm x 100mm.

arctic_silver_mittoniSo where to buy Arctic Silver 5?
Remember, the PC gaming community are into this stuff as well, and PC shops become an obvious source, especially the plethora of on-line merchants.

At $35 for a 12g syringe, Australia distributor Mittoni have no problems about under-cutting their resellers!

A quick search for the product reveals the 12g syringe can be purchased for much less than what Mittoni ask.
arctic_silver_iibuyI chose to buy from iiBuy, an on-line merchant that has been reliable and hassle free in the past. Conveniently, they also offer payment by PayPal.

iiBuy have several products from Arctic Silver, and the same 12g syringe is a more reasonable $22.
Compared to the likes of “Office works”, on-line computer stores are generally much cheaper when it comes to purchasing one of the most expensive fluids on earth – printer ink.

So while I was at it, I got some genuine ink cartridges for the printer (as a professional photographer, don’t waste your time with generic inks), which averages down the already modest postal costs ($8.95) for the Arctic Silver 5.

Once the Arctic Silver 5 arrives, and the faces of the copper heat spreaders and heat sinks have been milled, I will be documenting the progress of heat sinking the Power Amplifiers.

Stay tuned!