Speaker
Description
Conduction-cooled embedded computing applications for space platforms face escalating thermal management challenges as processor power densities continue to increase.
Traditional two-phase thermal systems (heat pipes, loop heat pipes, vapor chambers) exhibit gravity-dependent performance and are vulnerable to malfunction under high G-forces during launch, requiring extensive qualification testing and inspection protocols.
This presentation introduces a gravity-agnostic solid-state thermal solution combining PHENOMENA™ II Copper-Diamond (Cu-Di) composite alloy heat spreaders with PHENOMENA™ I diamond-enhanced thermal interface material (TIM) paste.
The PHENOMENA II Cu-Di composite alloy achieves exceptional thermal conductivity ranging from 700-800 W/m·K through a proprietary sintering process that integrates high-quality mono-crystalline diamonds (Tc > 2000 W/m·K) with pure copper powder (Tc = 394 W/m·K). Unlike two-phase systems, solid conduction materials maintain consistent thermal performance regardless of orientation, acceleration, or microgravity conditions, significantly improving reliability factors for space missions while reducing inspection requirements and qualification complexity.
The material demonstrates thermal conductivity attenuation of less than 5% after 1000 thermal cycles (-55°C to +175°C), making it ideal for long-duration space missions.
The synergistic performance is realized through PHENOMENA™ I TIM paste, which employs ultra-high concentration nano-particle formulation to bind high-quality diamonds in a monolayer configuration between processors and Cu-Di heat spreaders. This creates direct diamond-to-diamond thermal pathways that minimize interface resistance while maintaining electrical isolation. The paste demonstrates vacuum compatibility to 6.0 × 10⁻⁷ kPa with minimal outgassing (TML 0.06% at +200°C), meeting stringent space-flight requirements.
An additional advantage is the integration of HEATBIND solid retainers, which provide structural stability under launch vibration and thermal cycling while enhancing the thermal pathway between modules and their chassis.
Compared to conventional copper or aluminum heat spreaders with standard TIMs, the PHENOMENA™ diamond combination offers up to 50% reduction in junction-to-case thermal resistance while providing mass savings of 15-20% due to the composite’s lower density (5-6 g/cm³) relative to copper (8.96 g/cm³). The low coefficient of thermal expansion (5.0-7.2 × 10⁻⁶/K) closely matches semiconductor packages and aluminum chassis, reducing thermomechanical stress.
This presentation will demonstrate measured thermal performance data from ADHA plug-in modules operating FPGA devices, discuss design considerations for space-qualified applications, and present lessons learned from prototype implementations.