Fluid-Flow-Through Cooling

Advanced Packaging
Fluid-Flow-Through Cooling

System High Power Densities Achieve Reliability with AFT Cooling

Fluid Flow Through Cooling

Curtiss-Wright has patented a system known as fluid-flow-through (FFT) cooling (as shown in the image to the right). In this case, the fluid can be either liquid or air. The main difference is that FFT has fixed channels (air-cooled or liquid-cooled) built into the chassis.

In addition, it uses conduction-cooled modules – conduction frames attached to printed wiring boards (PWB) – whereas AFT has the air-cooled heat exchanger channel within a frame attached to the PWB. FFT allows for the highest net air flow rate due to no sealing required. You can even use standard conduction cards.

The LFT version of an FFT chassis uses a similar approach to the AFT version but employs liquid instead of air. As with traditional LFT, liquid is a much better coolant. With the LFT version, the channel design is optimized for liquid flow.

The benefits of the FFT approach are:

  • The air-cooled or liquid-cooled channels are fixed (brazed or bonded) into the chassis, eliminating problems with separable interfaces
  • There are no AFT seals that might blow out due to pressure
  • There are no LFT connectors that can leak or drip and harm the system

Thermal Management in Rugged Computer Systems

This white paper looks at the different cooling techniques available and aims to provide clarity on how to choose the best solution.

Cooling Techniques

Air-Flow-Through (AFT)  
Air-Flow-Through (AFT)

Ideal for high density, high power computing applications where conductive or convective cooling methods are less viable

Conduction Cooling  
Conduction Cooling

Ideal for lower density (50W) computing applications that require ruggedization

Convection Cooling  
Convection Cooling

Transfer of heat from electronics into the ambient air using airflow

Liquid-Flow-Through Cooling  
Liquid-Flow-Through Cooling

LFT cooling uses a liquid-cooled system to cool cards from 200-1000W