{"id":4941,"date":"2017-11-01T00:00:27","date_gmt":"2017-10-31T23:00:27","guid":{"rendered":"http:\/\/hwcooling.net\/vodni-chlazeni-primo-v-kremiku-dokaze-zkrotit-1000-w-tepla\/"},"modified":"2018-02-10T16:26:37","modified_gmt":"2018-02-10T15:26:37","slug":"new-means-to-cool-1000w-of-heat","status":"publish","type":"post","link":"https:\/\/www.hwcooling.net\/en\/new-means-to-cool-1000w-of-heat\/","title":{"rendered":"New means to cool 1000 W of heat"},"content":{"rendered":"\n

PC coolers have made a big progress over past ten years. But chips that are meant to be cooled also “improved” \u2013 TDP grows and temperatures are worsened by compounds under heatspreaders. The good news is that cooling these \u201chungry\u201c chips is a problem for the entire industry, so research teams of universities are trying to find a\u00a0solution.\u00a0<\/p>\n

At Purdue, they have developed a quite radical invention that is supposed to be able to cool chips that produce a heat with a density of 1000 W per cm\u00b2.\u00a0The research of the team led by Professor Suresh V. Garimella of Purdue University<\/a>\u00a0had the intention of creating a\u00a0cooling system that would be significantly more efficient than conventional ones. The key thing should be that the chip will be cooled directly, rather than cooled by a passive cooler or a block that only touches the chip. This, according to researchers, limits how quickly a heat can be removed from the chip. After all, we all know that transferring the heat from chips to heatsinks is often a\u00a0barrier.<\/p>\n

Purdue University therefore proposes to transfer the heat to a cooling medium (in this case a liquid) which is directly on the chip, or more precisely in the chip. This is accomplished by using microchannels in the surface of the silicon through which circulates the fluid from the cooling circuit. They work like channels in a water block. However, in this case, the channels are actually microscopic, their width is only 10 to 15 micrometers. Their depth is much larger, up to 300 micrometers. These little ducts are tightly next to each other so a dense ribbed heatsink is created on the upper side of the chip (transistors and circuits are at the bottom in conventional casings).<\/p>\n

With such narrow channels, the liquid does not flow too easily, so it is not possible to make it travel along the whole length of the chip, which would make the system much simpler. It was necessary to shorten the “paths” so that only 250 micrometres are needed between the outlet and the inlet. This is ensured by a grid, applied on the surface, as you can see in the microscope images. There will be probably a large number of gaps for the inlet and outlet of the liquid, which will somehow have to be resolved by a block that will be put on the chip.<\/p>\n

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Microscope photo in which you can see the microchannels in silicon<\/figcaption><\/figure>\n

The liquid in the circuit should be electrically non-conductive\u00a0HFE-7100<\/a>. It boosts the heat transfer by boiling. Especially this makes it possible, according to tests, to \u201cneutralize\u201c mentioned 1000 W of heat produced by the silicon chip (1 cm\u00b2). For comparison: when cooling Core i7-8700K, you need to take care of only 100 to 200 W (after OC) in 1.5 cm\u00b2. This requirement came from DARPA agency which was involved in financing of the project. Potential applications of technology can be, in addition to supercomputers, even in chips for military radars.<\/p>\n

The use of this cooling system will require a soft engraving into the finished manufactured chips, but it will be particularly complicated to use the block that solves the liquid supply to the microchannels. Most likely, it will not be available in personal computers in the near future. However, there is one area where this technology might be even necessary \u2013 in chips with more layers. A cooler mounted on the top of the casing removes much less heat from the bottom layers. If logic computing circuits are to be layered as well as memory, then a similar system will be needed, although it will be also necessary to solve how to distribute the channels in the space between two chips sitting on each other.<\/p>\n