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Intel rumoured to restore soldered heatspreaders in Haswell-E

Intel rumoured to restore soldered heatspreaders in Haswell-E

This image, published by OCDrift, shows what is claimed to be a de-lidded Core i7-5960X Haswell-E chip with a far more impressive heatspreader connection than its predecessors.

Intel is expected to return to using solder or a high-grade thermal epoxy as the thermal interface material between the die and heatspreader in its upcoming Haswell-E processor family, after swapping to a thermal grease solution on previous models.

The metal lid of the heatspreader sits above the die on most modern processors, offering both protection to the fragile silicon and an increased surface area for the heatsink to which it will be connected. A heatspreader only improves performance if it makes a better connection to the die than the heatsink would have, however, and that can depend entirely on the means by which the two are joined.

Previously, Intel has soldered its heatspreaders directly to the die, creating a strong bond at the molecular level that ensures good heat transfer. In its Ivy Bridge family, it moved to using a thermal paste with an impact in heat transfer and a sudden resurgence of interest in de-lidding accessories. Although many considered the move to have been made out of a desire to boost profits, there were sound engineering reasons relating to smaller die sizes causing cracking of the solder and the formation of heat-trapping voids that can damage the chip.

Those issues appear to have been resolved in time for the Haswell-E enthusiast chip family, thankfully. An image published by OCDrift shows a de-lidded Core i7-5960X Haswell-E processor with half the die stuck to the heatspreader - suggesting that solder or an extremely strong thermal epoxy, rather than the weak-adhesive thermal paste of previous chips, has been used to join the two.

Intel, naturally, is not commented on unannounced products, with rumours suggesting the Core i7-5960X will be formally launched in September this year - with or without the claimed new heatspreader interface material.

9 Comments

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faugusztin 28th July 2014, 14:10 Quote
"smaller die sizes causing cracking of the solder" -> "Those issues appear to have been resolved in time for the Haswell-E enthusiast chip family".

Well, the solution is probably the fact, that S2011 cores in general are damn big :D.
Corky42 28th July 2014, 14:25 Quote
By the looks of the picture it seem they may have switched to epoxy.
MrJay 28th July 2014, 15:20 Quote
Looks like they ****ed that CPU when they de lidded it : /
ZeDestructor 28th July 2014, 15:31 Quote
Quote:
Originally Posted by Corky42
By the looks of the picture it seem they may have switched to epoxy.

Why would you think epoxy rather than straight solder?

Based on Toppc@coolaler's Ivy-Bridge-E leak back in the day (http://www.coolaler.com/showthread.php/305405), the epoxy around the die looks very similar (identical if you ask me, and I've seen my fair share of bare dies on laptop chips...) to the Haswell-E core, so one would think straight solder rather than metallic epoxy, no?

Mind you, Toppc seems to have used a heatgun of some sort to melt the solder rather than straight lid rip...

Interestingly though, that looks like the 12-core die rather than the expected 8core die.. someone tore up a Xeon 12-core perhaps?
azazel1024 28th July 2014, 15:54 Quote
Quote:
Originally Posted by MrJay
Looks like they ****ed that CPU when they de lidded it : /

That'll buff right out.
Corky42 28th July 2014, 16:36 Quote
Quote:
Originally Posted by ZeDestructor
Why would you think epoxy rather than straight solder?
<Snip>

Nothing other than looking at the picture TBH, it just doesn't seem very solder'ie to me as it seems to lack the typical shine you would get from fresh solder. That and the way is looks around the edges of the die where it seems to me you can see the epoxy/solder in it's clean state and where it seems to have been pulled apart, to me it looks similar to an epoxy break than a solder break.

In the end it's pure guess work on my behalf though :)
ZeDestructor 28th July 2014, 16:46 Quote
Quote:
Originally Posted by Corky42
Nothing other than looking at the picture TBH, it just doesn't seem very solder'ie to me as it seems to lack the typical shine you would get from fresh solder. That and the way is looks around the edges of the die where it seems to me you can see the epoxy/solder in it's clean state and where it seems to have been pulled apart, to me it looks similar to an epoxy break than a solder break.

In the end it's pure guess work on my behalf though :)

That would be easily explained by the fact they seem to have ripped the die from the PCB it's mounted on. The evidence lies in the relative height of the epoxy residue. Aside from being fused to the lid using solder or some other form of molecular-level bonding, I don't see how you can get epoxy that's strong enough to rip the die right off the underside contacts....

I could be wrong, but judging by the epoxy breaking around the die solder-down location, the epoxy would have broken before the die got ripped out...

Also, pay attention to the very shiny "overflow" of what seems to be solder on the bottom edge of the die on the lid...
Corky42 28th July 2014, 17:12 Quote
Epoxy is used in the aerospace industry so there is no doubt it can be very strong.
Either way, solder or epoxy should be a big improvement on the thermal grease they've used previously.
IDK how much difference thermally there is between the typically used solder and a good thermal epoxy.
RichCreedy 28th July 2014, 20:31 Quote
the shine is reminiscent of a high silver content solder
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