When we talk about liquid cooling, the first thing that comes to mind are the radiators built into the box of our PC. However, in recent years designs have been developed that are based on connecting components vertically. What makes thermal choking higher, this forces designers to lower the clock frequencies of their designs. This has led to the development of various solutions, such as the use of peltier plates. TSMC’s bet? Literally integrate the radiator inside the processor.
Integrated liquid cooling by TSMC
During the VLSI symposium, TSMC engineers gave a preview of their research based on on integrating liquid cooling inside the chip as a solution to the problem of thermal choking in 3DIC designs. Which consists of integrating the pipes through which the cooling liquid passes inside the chip itself.
The reason for developing this technology by TSMC is clear, when cooling a processor today we usually use solutions that cool the outermost layer of it. Since most designs are not made up of multiple chips vertically, conventional cooling systems are good enough. The problem comes when we consider a design with several vertical chips, where traditional refrigeration systems are not efficient enough.
TSMC has investigated various ways of cooling the inside of the chip, both in terms of distribution and in the way of delivering liquid cooling to the different layers of the chip. In the end his conclusions have been that the best method is the Direct water cooling, which can dissipate up to 2.6 kW of heat and offers a temperature delta of 63º C.
Of course, this has just been presented and from here until we see this technology used in the chips of our PC we will still have to wait a few years.
Not only TSMC is looking into it, but so is Intel
There is no doubt that temperature problems when designing and developing integrated circuits are not exclusive to TSMC, Intel is also developing processors of this type and focusing its factories and future manufacturing nodes on it. Which implies that they are also going to run into the same problems as TSMC.
However, Intel will not be idle, as we have learned through the publication of a patent, entitled LIQUID COOLING THROUGH CONDUCTIVE INTERCONNECT. What translates to liquid cooling through conductive interconnections. Which goes to show that the problem of thermal capping in 3DIC designs is common throughout the industry and a problem big enough that the world’s two largest chipmakers have started researching and developing solutions to solve the problem.