Where to get small heatsinks for a DSL modem?

[Whib96]

So, my family's old DSL modem died on us recently, which I am assuming to be because the board was fried. It had gone for 2 years without any cooling and with no airflow on the bottom (it was set upright on a desk, basically allowing only the top of the modem to radiate heat, which didn't work well).

We purchased a new one and I want to put a heatsink or two in this one to prevent it from getting fried like the last one. The problem is that I have no idea where to get the size heatsink I'm looking for...

The main chip (which I believe is the modem's CPU) is 20mm x 20mm. Now bare with me, I'm a complete newbie when it comes to computer cooling stuff. Where would I find a heatsink that small, and does it really matter if it's copper or aluminum? Also, would it really matter if the heatsink was larger than the chip?

Again, bare with my newbiness, please. I'm merely a teenager learning the basics of computer cooling

 

[C12Friedman]

As far as size of heat sink, it should be at least the size of the chip you want to cool - bigger is better but you have space constraints to worry about also. Copper is better as a conductor but either material should work fine (BTW, diamond is best but a little cost prohibitive). I would be looking at laptop heatsink/fan combinations for a general idea and possible fit but some passive heatsinks (such as found on north and south bridges of motherboards) may be effective also.
Placing the modem on a small notebook cooler may be an option also

 

[Whib96]

Well, I'm not sure exactly how I'd get a fan in there. I'd have to do a lot of dremeling to fit it right. I'll probably just get a passive heatsink. Let me ask you this though...Can a single heatsink cover more than one chip, or do I need one for each?

 

[C12Friedman]

A single heatsink can provide cooling to more than one chip provided the chips are at the same height on the PCB and there are no obsticles between. Look also at your transistors since they tend to be heat producers also (depending on quantity and spacing)

 

[Whib96]

As of now, I think all I really need is some heatsinks. Do you know where I could buy some of that size? Most of the big PC hardware sites don't have a very good selection of heatsinks...

 

[amuffin]

You could always buy those simple heatsinks you find at electronic warehouse, like Halted, or Weirdstuff. Don't know if their anywhere near you....anyways you could just take a hacksaw and cut them down to size, get thermal pads, then tape them down.

 

[smorizio]

http://www.moddiy.com/products/Black-Chipset-Heatsink-%2820mm-x-20mm-x-6mm%29.html#.UG0KeVHA0e4
also look to see if you can put a small 12v laptop fan on the top as an output for hot air.

 

[Whib96]

I'll definitely look into a fan eventually. Right now I just wanna find some good heatsinks. Does the height of it matter so much? I could fit nearly a 30mm tall heatsink in this modem, so if I can get one about that tall I'd like to.

 

[NoUserBar]

What about buying a new modem, is that an option? I know it's not what you want to do though.

 

[Whib96]

Not really. I mean, the whole point of doing this heatsink deal is so that I WON'T have to buy a new modem, considering all DSL modems are known for getting way hotter than they should get. Therefore, they need cooling if they're going to last. Right now I've just used a dremel to create bigger and more vents in the casing.

 

[C12Friedman]

Here's a package of 8 each 20mmx20mm heatsinks from Directron for $6 - good for a few modems
http://www.directron.com/rhs02.html
they even come with thermal tape

 

[Whib96]

Should I look for some taller ones, considering I could fit a pretty tall heatsink in this modem? 6mm is awfully short and I just wanna make sure I'm getting what I'm hoping for.

 

[C12Friedman]

I wasn't sure of your space constraints... here's another option - a little more expensive
http://www.frozencpu.com/products/5519/vid-83/Enzotech_Forged_Copper_Northbridge_Heatsink_CNB-S1.html?tl=g40c16s229
I would look to use thermal tape such as this
http://www.frozencpu.com/products/10223/thr-75/3M_8815_Thermally_Conductive_Adhesive_Transfer_Tape_-_2_x_2.html?tl=g8c487s1291
for mounting (get rid of the screws)

 

[Whib96]

Okay, last question I swear...Can you put two heatsinks directly beside each other? For example, can you say make one square with 4 small square heatsinks, having all of them touching? I assume that wouldn't hurt anything and you'd just need to put thermal tape on each individual one.

 

[Reynod]

Yes you can ... it will be fine.

I removed the cover on one of my early DSL modems because it used to overheat - I found references on the net about it. In hindisght I should have put a couple of my old ram heatsinks on it I guess.

You could cutaway part of the side of the case and fit a small USB type fan (if the modem has a usb socket on the side like my new one has) ... 5V.

Use the dremel if you have one to drill out the holes around the side of the modem to allow more air to flow - I suggest taking the cover off the modem to drill the holes out ... don't do it while assembled as you might damage the components.