One of the limiting factors for the computing power of processors is the operating temperature. A research team led by Dr. Wolfram Steller, Dr. Hermann Oppermann, and Dr. Jessika Kleff from the Fraunhofer Institute for Reliability and Microintegration IZM, has developed a new as well as an efficient cooling method by integrating microchannels into the silicon interposer. For the first time, it is possible to cool down high-performance processors from the bottom as well.
When processors get too hot to work properly, they reduce their clock speed and operating voltage. In order to protect the CPU and motherboard from getting fried, the processors either reduce their computing speed or even shut off completely. Until now, cooling elements and fans are used to avoid overheating the heat-sensitive components. The researchers found a way to cool processors from the top as well as from below using a liquid-based cooling system.
The research team reports that the innovation can achieve a significant increase in performance. The scientists have also integrated passive elements for voltage regulators, photonic ICs, and optical waveguides into the interposer. This enables highly effective cooling and therefore higher performance. For this purpose, microchannel structures with tightly sealed vias are installed in the silicon interposer, which is located between the processor and the printed circuit board.
Interposers are responsible for the electrical supply and cooling of the processor. Every 200 micrometers, interposers are equipped with electrical connections to ensure the processor’s power supply and data transmission. In order to be able to absorb heat and channel it away from the processor, the researchers at Fraunhofer IZM created microfluid channels that allow coolant to be circulated through vias.