Technology
As semiconductor performance increase, temperature and temperature non-uniformity increase to problematic levels. Heat loads are rarely static and there are cases where temperature fluctuations are significant. In the past this has not been much of a problem as heat dissipation was modest. However, transient thermals have become complex and vary form milliseconds on the chip level to minutes on the PCB level. A ultra low thermal resistance liquid metal cooling system help limiting this phenomenon. Further, a liquid metal cooling loop can change the dynamic flow in milliseconds, thereby increasing or reducing the cooling capacity fast in effect limiting temperature fluctuations. We call this dynamic cooling which is basically a cooling system with variable thermal resistance.
Liquid metal has several major advantages when cooling high power density heat sources:
- It has superior thermo physical properties decreasing temperature and temperature non uniformity
- It has high electrical conductivity enabling efficient, reliable and compact EMP propulsion without the use of moving parts, shafts, seals etc.
- It has a vide temperature operating range and remains liquid from -12,6°C all the way to 785°C.
- Unlike a two phase heat pipe, a liquid metal cooling loop has a near constant thermal resistance within the operating temperature range. This makes it ideal for cooling of high temperature semiconductors operating well above 100°C. That is well beyond what commercially available water coolers can handle.
- A liquid metal cooling loop is orientation independant.
- Tighter packaging of components is allowed, due to the liquid metal cooling loops light weight, small size and maintenance free operation.
By contrast, large and bulky water pumps, large size radiators, shafts, seals, tubes & connectors are difficult to implement and pose a hazard risk of water leaks capable of destroying the entire system. There is no such thing as a maintenance free water cooling system. These design are not hermetic thereby enabling exchange of mediums with the ambient environment. Eventual, these systems will need refilling as water vapor will slowly escape from the system when hot. Transport of oxygen into the system will also occur and that is even more problematic as this means that the water turns corrosive and thereby destructive against the construction elements which could result in a catastrophic leak.
The ideal environment for a liquid metal cooling loop is a small form factor application with an embedded high power chip and a high ambient operating temperature. Such applications could be next generation telecommunications radio equipment or high power LED applications.
How do you implement a liquid metal cooling loop into your design? It's actually easy - it is implemented into your solution in the same way a heat pipe is.