IBM unveils water-cooled 3D chip prototype

IBM on Thursday announced plans to use water to cool its next-generation of computer chips internally, allowing it to develop faster multi-layer processors that don't require additional external cooling. To this end, the company showed off a prototype 3D chip with thousands of tiny water passages in between the chip's layers. The company says interlayer cooling was necessary, as traditional heat sinks weren't efficient enough to cool today's densely packaged processors. The water-carrying tubes are just 50 microns in diameter, and integrating them into the chip necessitated the development of a new thin-film soldering technique by IBM engineers.

To prevent electrical shorts, the passageways were hermetically sealed using a silicon wall and silicon oxide around each interconnect. At 10 microns, these seals required a fabrication accuracy that is 10 times more precise than for current chip interconnects.

The final chip sits in a silicon cooling container, with water pumped in through one side and out the other. While water-cooling computers is not a new concept, this is the first time it would be accomplished on such a miniature and large scale. According to IBM, the technology could find its way into consumer-level products within five years.