The trend among the microprocessor manufacturing industries is that every year, it will dive into the world of radical CPU water-cooling and offer the results of its research. This year, TSMC gave its presentation on the topic, and oh boy, the results they produced might theoretically be a long-time solution to this recurring problem.
As we know, AMD is currently working on a version of its Zen 3 CPU core with 128MB of integrated L3 cache. However, the manufacturer needs to carefully position the cache chips to avoid causing hot spot problems within the Ryzen die. And this vertical die stacking has driven the semiconductor density throughout the 2020s.
All the chip manufacturing industries have the tremendous ability to stack chips on top of each other; however, they cannot keep the silicon stack from roasting in its heat. This has created several problems, and the OEMs that offer high TDP like NVIDIA and Intel need to provide some types of on-package (or on-die) water cooling, which has to be at least partially integrated.
However, in TSMC’s research with Direct Water Cooling, the company etched the water channels directly into the silicon layer on top of the CPU. for the second test, silicon channels were etched into a silicon layer with a silicon-oxide thermal interface which exists between the microfluidic system and the actual silicon. The final test included the silicon-oxide TIM, which was replaced with a liquid metal TIM.
TSMC reported that Direct water cooling performed the best and is far more efficient than anything available today. However, this is just a theoretical answer using a thermal test vehicle/proof of concept and not the final product.