Chemical Vapor Deposition Diamond Heat Spreaders : Ever wonder what the next generation cooling technologies are for cooling next generation processors? Chemical Vapor Deposition Diamond surfaces is one. Diamond is applied to silicon processors to improve surface thermal conductivity substantially according to this report from the University of Maryland. Of course the high cost of producing diamond heatspreaders means that more economical alternatives like Electroless Nickel, with a thermal conductivity of 90.7 W/m/K, could also work. Other exotic cooling technologies mentioned in the VITA report include; Heat Pipes Liquid Cooling Spray Evaporative Cooling Chip Refrigeration (Phase Change Cooling) Cryogenic Cooling Thermoelectric Cooling Non-Metallic Microchannels Meso / Micro Cold Plates

Metal Foams as High Performance Heat Exchangers: This research study conducted by the Laboratory of Thermodynamics in Emerging Technologies (LTNT), has studied the possible use of a foamed aluminum material for use as a fancy waterblock. With all heat exchangers, one of the most important aspects is optimizing thermal transfer between the fluid, and metal. Forget milling small pathways out of solid metal, foamed aluminum has the general structure of a sponge... and with the right amount of fluid flow could lead to a highly efficient cooling solution. If this grabs your attention, see the PDF on 'three dimensionally structured fluid-saturated metal foam' and 'Effects of compression and pore size variations on the liquid flow characteristics in metal foams.'

Fraunhofer Institute's 100 µm-density heat exchanger: The Fraunhofer Institute for Manufacturing and Advanced Materials (IFAM) has pioneered metal fiber structures, along with hollow spheres structures and metal foams. In the case pictured below, Direct Typed structures are printed with gas atomized 316L stainless steel. Given the right design, you could be looking at some of the worlds best potential heat exchangers here... "A printable suspension of metal powder and a binder is pressed in a screen printing process through a computer generated mask, followed by a hardening step. In the next step a layer-on-layer printing is repeated until a 3-dimensional part is manufactured. A first heat treatment is applied to remove the organic binder; subsequently the remaining metal powder is sintered to structures with high precision and good mechanical stability. The residual minimal wall thickness and channel width amounts about 100 µm. In contrast, the maximal structure height may add up to a couple of centimeters. Hence, exceedingly high aspect ratios are feasible. The method enables the production of 3-dimensional structures with horizontal apertures or closed channels."

Tamagawa Zigzag Heatsink Fin Concept: Tamagawa, a Japanese metal products company, has developed a very unique heatsink fin concept for what it calls 'advanced cooling' situations. The heatsink fins are formed into a zigzag pattern, composed of offset micro squares stacked on top of one another to form fins about 10-30mm tall. The surface area and complex flow patterns that would result from such complex interlocking fins may possibly produce a very efficient thermal shape for increasing heat dissipation in limited spaces. We would expect that high-volume forced air cooling would be used to combat the pressure drop. Shown are two examples of Tamagawa's 'zigzag' cast aluminum and cast copper heatsink concepts. The copper prototype measures just 40x20x10mm in size, the aluminum model appears to be somewhat larger.

Injection Molded Copper from Amulaire: Most aluminum heat sinks exist as extrusions that allow intricate shapes in only two dimensions. "By injection molding copper, though, engineers have more control over the intricate shapes on a heat sink," said Ken Kaskoun, VP of Sales and Marketing at Amulaire Thermal Technology. "Molded copper lets us increase the amount of metal over the chip and then taper off the base thickness at the heat-sink edges or we can create an airfoil to increase air flow across an area," said Kaskoun. The molding process also lets customers include mounting features without the need for machining. To create a molded-copper heat sink, Amulaire simulates a design and then machines one or two prototypes." "Unlike plastic, you cannot inject molten copper into an intricate mold. Instead, Amulaire Thermal Technology combines fine copper with a polymer binder and injects the mix into the mold. "The part comes out of the mold with the consistency of chocolate," said Ken Kaskoun, VP of Sales and Marketing at Amulaire. It then goes into a sintering oven that drives off the binder and leaves the fused copper behind. The design shrinks uniformly by about 20 percent as it goes from the molded to the sintered state, said Kaskoun. "After sintering, we have a copper part that has 98 percent of the density of solid copper."