Heat Spreaders
Pyrolytic Graphite and Copper Heat Spreader Plates
Heat spreaders are high-conductivity plates composed of OFHC copper, vapor chambers, diamond-copper composites, or pyrolytic graphite sheets that distribute concentrated thermal loads laterally to reduce peak temperatures at component hot spots. In the lunar vacuum, electronics packaging depends on effective spreading to route heat into conduction-cooled cold plates. Pyrolytic graphite sheets provide an in-plane conductivity four times higher than copper, though their brittle nature requires mechanical protection against handling damage. Additionally, spreader materials must maintain compatibility with mounting interfaces to avoid galvanic corrosion across electronic assemblies.
High-conductivity plates spreading concentrated heat sources over larger areas
Purpose
Reduce peak temperatures at component hot spots by distributing heat laterally
Context
Child of L2-TCS-INTF in the Active Thermal Control System
Principles
- ▸Pyrolytic graphite sheet (PGS) has in-plane conductivity 4x higher than copper
- ▸Vapor chambers provide isothermal heat spreading via internal phase change
- ▸Copper heat spreader plates used under high-power electronics packages
- ▸Diamond-copper composite offers ultimate thermal spreading for extreme applications
Typical implementations
- ▸Panasonic PGS (Pyrolytic Graphite Sheet) thermal spreaders
- ▸Advanced Cooling Technologies vapor chamber heat spreaders
- ▸Momentive Performance Materials diamond-copper composites
Lunar considerations
- ▸Electronics packaging in vacuum requires effective spreading to conduction-cooled cold plates
- ▸Spreader materials must be compatible with mounting and not create galvanic corrosion
- ▸PGS is brittle - must be mechanically protected from handling damage
Specifications
Functional
| primary function | High-conductivity plates spreading concentrated heat sources over larger areas |
Physical
| materials | Pyrolytic graphite sheet, OFHC copper plates, Vapor chamber assemblies |
Interfaces
Provides
- Heat spreading under processor packages
Requires
- Equipment mounting surface interface
Cite this entry
Lunar Ark Codex. "Heat Spreaders" (L3-TCS-INTF-SPREAD). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-TCS-INTF-SPREAD
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.