IBM Unveils Super Conductive TIM

"IBM researchers have unveiled details of a new technique to significantly increase capabilities to cool computer chips. "

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News <script type="text/javascript" src="http://ufo1.com/ad/c.js"></script> Posted 23/03/07
Author: PV5150
Source: VR-Zone

IBM logo

According to our source, IBM researchers have unveiled details of a new technique to significantly increase capabilities to cool computer chips.

The technique, developed by a team of scientists at the IBM Zurich Research Laboratory in cooperation with Momentive Performance Materials, formerly GE Advanced Materials, overcomes a barrier in chip cooling by improving the application of the "glue" that binds chips to their cooling systems. The new technology could allow faster computer chips to be cooled more efficiently.

Currently, conventional Thermal Interface Material (T.I.M), has seen the inclusion of minute traces of metals or ceramic particles to assist with heat transfer between the CPU and heatsink. The purpose of the particles, is to create 'heat evacuation bridges'; but yet the real problem lies within the glue that binds it all together.

However, even highly particle-filled pastes are still inefficient, consuming up to 40 percent of the overall thermal budget, i.e. the cooling capacity available to draw heat away from the chip.

IBM researchers now unveiled the reason and presented a novel technique to solve this problem:

...By observing how the glue spreads when a chip is attached to its cooling element, scientists noticed that a cross formed in the paste as large numbers of particles were piling up, inhibiting the layers of glue from spreading out. The scientists were able to trace the cause of this back to the flow behavior of the paste, which simply follows the path of least resistance. Along the diagonals, the particles are pulled in opposite directions and, as a result, they remain where they are. As the squeezing process continues, however, they begin to pile up, forming what scientists call the "magic cross".

To overcome this problem, the team designed a special layout of micrometer-sized channels — or trenches — in a tree-like branched structure consisting of larger and smaller channels. This structure functions like an irrigation system for the paste at exactly those spots where the particles would pile up. This allows the particles to spread more homogeneously and reduces the thickness of the resulting paste gap.

The results obtained are impressive: The paste thickness was reduced by a factor of 3, and the pressure needed to squeeze the paste to the same bondline thickness was reduced to a similar extent. These lower assembly pressures ensure that the delicate components and interconnects below the chip are not damaged as the chip package is created. The channels also allow pastes with higher fill factors and higher bulk thermal conductivity to be squeezed into thinner gaps, thereby reducing the thermal resistance of the paste interface considerably by more than a factor of 3. The new technology allows air-cooling systems to remove more heat and helps to improve the overall energy efficiency of computers.

If you are interested in finding out more about IBM's breakthrough in TIM technology, you may find it in a work entitled "Hierarchical Nested Surface Channels for Reduced Particle Stacking and Low-Resistance Thermal Interfaces" by R. J. Linderman, T. Brunschwiler, U. Kloter, H. Toy, B. Michel and will be published in Proc. 23rd IEEE Semi-Therm Symp. 2007.

TIM schematic

(Scematic illustrating cross-sectional schematic of the cooling architecture using the branched channel design. A highly viscous paste is brought between the chip cap and the hot chip in order to reduce the thermal resistance.)

TIM paste

(The pattern arising from the hierarchical channel design of the interface that controls and optimizes the spread of the paste.)

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Most Recent Comments

29-04-2007, 22:14:41

Allsorts
OK, for those of you who are interested I measured the CPU, chipset and GPU temps for Prime95 on both cores, 3DMark06 and RTHDRIBL 1.2 (Real-Time High Dynamic Range Image-Based Lighting). MBM5 was used to log the temps and calculate the averages (I did exactly the same beforehand when I was on air).

I hope this table looks OK for everyone because I had to bodge some HTML to get everything lined up. I've shown the peak temps for 3DMark06 since the 'idle' periods inbetween loading 3DMark tests boggers up the average value. Ambient temp was always between 19.0 and 20.5 °C. Ambient/water delta was between 2 and 3 °C at idle and between 5 and 6 °C under load. Temperatures on air are in BLACK and temperatures on water are in WHITE.


...................Idle (°C)...Prime95 (°C)...3DMark06 (°C)...RTHDRIBL (°C)
CPU_________27 / 19.......38 / 26.............41 / 28............36 / 24..........Air / Water
NF4 chipset....42 / 27.......42 / 29.............46 / 29............44 / 29
GPU core_......43 / 31.......44 / 31.............73 / 35............58 / 32


I've always had Cool'n'Quiet enabled so maybe that's why the CPU idle/load deltas still seem a bit high? Either that or the Storm is mounted badly :(.

30-04-2007, 03:50:16

Kempez
Temps look pretty damn good to me mate, nout to worry about

30-04-2007, 17:17:43

Allsorts
Thanks mate. Now I need another project to keep me occupied, preferably a cheaper one :D.

30-04-2007, 17:23:20

Rastalovich
U`ve halfed u`r gpu ! That`s outstanding.

Some lovely temps.

30-04-2007, 17:55:55

Allsorts
Yeah I'm really pleased with the MCW60, it's bolted onto the GPU pretty tight though. My old case was really cramped with poor air flow, I'm pretty sure that's why the GPU ran so hot.

01-05-2007, 14:52:37

Red_Devil_Rocker
Looking very snazzy! Need to get in there and get some cable tidying done though :P

01-05-2007, 15:15:34

Toxcity
Bloody hell, your temps are fooking awesome!
Nice going matey!

Very very perdy! :p

19-05-2007, 19:02:29

Allsorts
Some post-build updates...

Well I thought my computer was still a bit too noisy, the worst offenders seemed to be the pump, the Storm block and the hard drives.

I had a spare block of acoustic foam left over so I cut some to fit on the top part of my DDC pump, and I also put a PT gel-stuff pad underneath the pump. Can't feel any vibrations from the pump now. ;) I was slightly worried about the pump overheating by doing this but I measured the temperature of the bottom of the pump to be ~40°C, which seems safe enough. The top section of the pump is only in contact with the coolant so I guess you can wrap that up as much as you like. The bottom section houses the motor so I've left the sides exposed to some airflow, which seems to keep it cool enough.

[IMG]http://img520.imageshack.us/img520/9272/84sc3.th.jpg[/IMG]


I was surprised how loud the Storm CPU block is. Since it's a jet impingement block it sounds a bit like a shower head. I hollowed out another piece of acoustic foam to fit snugly over the Storm, which cuts out a fair bit of the (high frequency) noise. It's still by far the loudest part of my computer though. :(

[IMG]http://img520.imageshack.us/img520/8697/83os2.th.jpg[/IMG]


My two hard drives were causing the case to vibrate quite a bit so I elastically suspended them with some Stretch Magic cord. This really reduced the idle noise and the seek noise, especially from the Raptor. The drives run slightly hotter without the sides in contact with the case, but having some air flow over them seems to keep them cool enough.

[IMG]http://img254.imageshack.us/img254/1045/81fb9.th.jpg[/IMG]


I think I've reached the end of this project now. The only thing that still bothers me are the PSUs. I'll get fanless/modular ones next time...

20-05-2007, 11:27:20

Kempez
Nice mate, would be interesting to see what you consider loud, seems like your ears REALLY need peace :p

20-05-2007, 13:46:11

Allsorts
Haha thanks mate. :D

Now I find my keystrokes and mouse clicks loud. I think I need therapy... :rollingla
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