For long the industry has been battling with high heat outputs in circuits, and stacking circuits have more or less become a standard for some kind of circuits. IBM has presented a new technology that can both cool and power these circuits using liquid metal.
So called 3D die-stacking, TSV (Through Silicon Via) simply allows for stacking circuits on top of each other. This common in smaller devices, like smartphones, where you have a system processor and etch the RAM on top. The advantages of this is quicker transfer speeds, communication between the stacked circuits and lower energy consumption. The disadvantage is how you cool the circuits, but also supplying them with power.
IBM has designed a technology that solves both problems, although just in the lab so far. IBM is doing a lot of research on artificial intelligence and often use the human brain as a role model, and it uses the same medium for transporting heat and energy.
“The human brain is 10,000 times more dense and efficient than any computer today. That’s possible because it uses only one, extremely efficient, network of capillaries and blood vessels to transport heat and energy, all at the same time,” IBM
IBM has created channels in its wafers to allow liquid metal – in this case Vanadium – to flow through a circuit. When you then stack multiple circuits on top of each other there are channels for the Vanadium. In IBM’s tests it has stacked hundreds of silicon-based circuits on top of each other.
Vanadium can transport charge through the stacked circuits for powering them and when it loses charge it can absorb heat, which also makes it a cooling agent. The idea is to have a single medium for both powering and cooling the stacked circuits.
3D die-stacking is the future, but what will we use to get rid of the heat and power problems?
If and when the technology will materialize we don’t know, and IBM has previously presented a similar technology with heat-conductive glue that could possibly also solve these problems. There is great potential with this technology, and it could result in both higher clock frequencies and lower energy consumption. Another problem that is often neglected when you see all of these numbers GHz (GigaHertz), is that as transistors operate faster the circuit will need faster commincation with other circuits. 3D die-stacking could solve this too, since stacking circuits reduces delays.
It really looks like TSV is the future in semiconductors, or that we will use some other kind of technology to come to terms with the energy consumption and heat development in modern circuits.
Source: New Scientist
