What's a copper shim?

[ThreeDollarBill]

Hmmmm.....??

 

[mrchan]

a copper shim is kind of like a flat square with the middle cut out. it's used for fc pga cpus and tbird/durons, it protects the core from damage when putting on a heatsink.

 

[insanepuppy]

If you want to see what they look like there is a few over at plycon.com

 

[ZeroBurn]

are they worth getting ?

 

[shiznut123]

i dont think they are worth getting. i would get one if my heatsink was putting high pressure on my cpu

 

[JJHendrix]

they are for protecting the core?
i thought it was for better heat transfer...
i plan on getting a globalwin vos32 (that big ass one) think i should get a shim as well?

 

[ZeroBurn]

i've got an Alpha PAL6035 on order, since that's designed for the Socket A's i guess i shouldn't bother getting one.

 

[AznBruin03]

hm.. i remember reading that some people still damamged thier processors even with the shim there.

 

[Kyle]

I screwed my Duron with out a shim and with an Alpha PAL6035, but that was cause I wasnt really being too careful.
Hopefully it won't happen to my new 1.3ghz Tbird that is comin

 

[JJHendrix]

define "screwed"?
does this stuff happen on a regular basis?

 

[Drachnyan]

Most of the newer cores put out use the FC-PGA
mode, or are more commonly known as flip-chips.
This include the p3s, duron and tbird cores.
Out of all of these the last two are notoriously fragile, having your hs/f combo improperly placed on
the core can cause your core to chip or possibly crack.

(this is bad)

The shim is there to help distribute the weight around
so that the hs/f cannot become sufficiently unbalanced to
kill your processor. It can also increase thermal conductivity (more stuff in contact w. the heat sink.) and
thereby keep your chip cooler as well as safe. Thermal
grease can be used to improve the conductivity further.
I'm planning on getting one for my new system, but
you can do as you wish. After all, it's your money.

Duron and Tbird users, if you do go shopping for a
shim/spacer (they're called by both names) find one
that has cut-outs for the feet on your processor, it'll
help stabalize the shim/spacer so it won't move and possibly grate against your chip.

 

[Mikewarrior2]

Drachyan,

That shims help thermal conductivity is a myth. They contact idle pcb, while a secondary heat pathway, it is not significant enough to effect cpu temp.

AMD recommends against them. I would suggest searching for "DaddyG" for more info on this.



Mike

 

[Drachnyan]

Mikewarrior2, I looked around, but couldn't find the post you were referring to, can you link to it? I wasn't suggesting the use of a shim w/o thermal grease. AMD
does design good processors, but the HSFs we strap to their chips to OC them arn't designed by them, that and some of use like to be careful. As for the secondary thermal pathway, every little bit helps... no?

 

[Mikewarrior2]

It would appear to help, but the real world benefits are probably nil. Remember that ceramic substrate is a very poor heat conductor, whereas the copper-shim touching the heatsink bottom is likely to "steal" away from heat from the heatsink, and trapping it in the shim, therefore possibly heating up the pcb.

As far as the other thread, here you go... dammit, i'll hvae to search for it later, the forum search function isn't working for me.

Shim Thread

My personal view is, if you're worried about cracking your core, its an investment that can save you money. I just wouldn't expect any thermal benefits from having it installed.


Mike

 

[johneetrash]

where can you get those spacers with the cutouts for the feet? any recommendations for any spacers? im paranoid about putting on the heatsink with everyone talking about cracking the core so ill probably invest in one of these if it's "safer."

btw im getting a 1GHz t-bird with a Tai-Sol CGK742092 (if this place im looking at still has it in stock)

 

[ZeroBurn]

i'm getting an alpha pal6035 for my 1.1ghz tbird, should i bother getting the shim to protect it? or is that pretty avoidable just by being careful. i also plan on applying extra artic silver, and thus having any extra smushed out of the sides, is this a bad thing?

 

[techg]

i just bought a pal6035 and a copper shim. i bought one with cut-outs for the feet, so it will stay aligned and i dont have to rip off the feet. im looking at the shim right now, and it looks pretty well made (got it from CPUFx, through overclockers hideout). i bought it for the sole reason that i wouldnt smash my core when i put the hsf on or when i took it off. i think its a good idea, and if it doesnt do anything to harm the proccessor, and according to tests, doesnt make the proccessor any hotter, then i dont see any reason for not using it to reduce the risk of a crushed core.

 

[DaddyG]

Here's some of Daddy's thoughts. The shim doesn't distribute weight per se. What it does do is prevent the heatsink from 'cocking' when fastening the clips. If the hsf is not flat against the core when the clips are fastened, the edge of the chip will crack.

The thermal pathway issue is a little more complex.The Socket A cpu has the primary pathway to the heatsink base, but, the ceramic base does provide a secondary pathway. The shim effectively connects both the primary and secondary. Since the hsf is hotter than the ceramic, heat will flow off the heatsink, which is not good. The fan has no effect on cooling the shim or the ceramic base.

The last issue is that if the shim is not manufactured to precise measurements, or is warped at all, it has the potential to prevent the hsf from seating firmly against the core. Thermal expansion can create problems here. AMD specs 12-20lbs pressure between the hsf and core and the shim must not reduce the pressure.

In a nutshell, a good shim protects the edge of the core, but they don't provide any better cooling, considering all the issues in effectively measuring Socket A temps.

 

[Mikewarrior2]

Thanks for checking in DaddyG!



Mike

 

[kengsim]

You can damage the core even if your HSF was designed for the chip. The problem lies with the HSF clip, some of which are VERY tight. I actually chipped my older P3-550E and I got scared. So I ordered a shim from 3dfxcool and found that it works very well.