Here's a post on all I did today, I think it'll answer your questions FastCargo as well as those of many others
So, I finally had some time after class today and thought I'd try beefing up this new card. Without further ado, HEATSINK, ROUND 2
I went for a different design this time, one that uses less copper and specifically isolates each RAM chip. Sorry about some of the pictures, it's a bitch and a half to get the macro to work right on my camera (and I really need a tripod to get steady pics).
Here's my starting tools and copper (I'm a little limited here at college
Here are several photos of the first heatsink (the one that would go on the lower left chip if you look down at the card). You can see the ~1.3cm square base used to cover the RAM chip with the fins extending. Each heatsink I had to trim here and there to fit to the card correctly once I took the card out for a physical fit test.
Here's another size comparison pic of the second heatsink (also goes on the bottom side of the card) as well as the rest of the heatsinks laid out as they would appear looking down on the card in the 9300. After this last shot I sanded each with 600grit sand paper to remove any finish, oxide, and sharp edges.
Now I'm going to take a little detour and show some pics of my AS5 applications, hope it helps you guys
Here's a pic of the old AS5 application as it looked when I took the heatsink off the core. You can see that I used way too much, which would account for the higher temps I was getting (97C or so in FEAR). Much of the excess was pushed out to the sides though, so the gentle pressing and rotation really does help. Also here is a picture of the ship which is still stuck to the heatsink. Again, you can see how the AS5 was pushed out to the sides, but also how the shim was rotated, so that's something to be careful of.
Here's the new AS5 on the cleaned core. I probably ended up putting about 50% more of the glob shown here, just because after I spread it out it didn't give enough contact to meet the shim. Also shown is the final amount spread out. For some reason, the glare makes it look like there's more AS5 than there really is
Here I have placed the shim on the core and pressed and rotated it on it so that it has superb contact. The shim is ~20mm-22mm square (it isn't perfect) and crafted from 0.025" copper plating. I sanded it with some 600grit and 1500 grit, so it's less than 0.025" now, maybe 0.02-0.022". I dabbed AS5 all over it and spread it out, which is shown in the second pic.
Here's my AS5 application on the RAM chips on the underside of the card. I spread out a semi-thin layer all over the chip and then add a little bit more in the middle to insure complete contact.
Here are the heatsinks in place on the underside of the card. Note that I have already pressed the heatsink onto the shim and slightly rotated it back and forth to ensure complete contact. Now all I have to do is place the back plate on and screw it all together.
ANNNDDDD the finished product
. I had to bend some of the fins here and there to make sure they didn't touch anything, but that's how it basically looks.
Well, my new AS5 application on the core helped a bit. Temps dropped from ~97C max in FEAR to 93C max in FEAR, which is pretty substantial. The heatsinks get burning hot (can't touch them), so they're definitely doing their job. Overall I'm pretty impressed with this mod and I think it works well. I wasn't so sure about the small fin design, but I think it does the trick. Also, there's less chance of the heatsinks touching any other components since they only project out directly from the chip.