How Embedded Systems are Coping with the Heat of Today's Avionics

Avionics International

Published in Avionics International

With faster processors, more functions, and higher bandwidth than ever before, today’s avionics are pushing the cooling technology envelope to the breaking point – and beyond.

“The result of this trend is increasing heat flux at both the component and circuit board levels with heat flux levels in excess of 100W/cm2 for commercial electronics and over 1000W/cm2 for selected military high-power electronics,” Nelson J. Gernert, VP of engineering and technology at Boyd Corporation’s Aavid thermal division, told Avionics International. “There is also a growing demand for more sophisticated and capable electronics used in harsh aerospace and defense environment applications.”

Embedded systems companies and others in this area are tackling the cooling conundrum with a number of innovative solutions. Here is how they are turning down the heat.

Helping Conduction Cold Plates Do More

Conduction is the most basic form of avionics cooling. The heat generated by the circuit boards is thermally conducted into a metal ‘cold plate’, where it is passively radiated away from the electronics into ambient space.

Boyd Corporation has bolstered the passive cold plate’s ability to conduct heat away from circuit boards (and components) by supplementing its line of solid aluminum cold plates with ‘aluminum k-Core®’ cold plates. These cold plates are made of aluminum encapsulated APG (Annealed Paralytic Graphite), which “combines the mechanical strength and CTE of aluminum with the increased thermal conductivity and reduced weight of graphite,” said Gernert.

Liquid Cooling Is Superior

Along with Abaco and Lockheed Martin, Curtiss-Wright sponsored the VITA 48.8 Working Group that brought this standard to the industry. In fact, Curtiss-Wright chaired this working group, which speaks to the company’s belief in the value of VITA 48.8 air cooling.

This said, VITA 48.8 is one only of the thermal solutions Curtiss-Wright is willing to use for avionics cooling, said Ivan Straznicky; a technical fellow at Curtiss-Wright Defense Solutions. Unlike Abaco’s Hoden, Straznicky believes that liquid cooling (in line with the VITA 48.4 liquid flow-through standard) is safe enough for use in high-end avionics systems; due to its many benefits.

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