Outdoor radio units are sealed, passively cooled, and expected to run for a decade on a pole. There is no fan to compensate for a bad interface — the thermal path has to be right at design time, and it has to stay right after thousands of day/night cycles.
Why telecom thermal design is unforgiving
- Sealed enclosures. No forced air means the only path out is conduction to the housing fins, so interface resistance directly sets PA temperature.
- Solar load. A black enclosure in direct sun can sit 20–30 °C above ambient before the electronics even switch on.
- Ambient extremes. −40 °C to +55 °C operating range is standard for outdoor units.
- No maintenance. Truck rolls are expensive; the TIM must not degrade over the service life.
40–60%
Typical PA drain efficiency — the rest becomes heat
−40…+55 °C
Standard outdoor ambient range
10 years
Expected unattended service life
Passive
Cooling in most remote radio heads
Where the pad goes
The dominant interfaces in a radio unit are the power amplifier to the housing, the baseband / digital board to the chassis, and the PSU to a thermal wall. In all three, the surfaces are large, the flatness is imperfect, and the assembly is done once at the factory — never to be revisited. That combination favours a conformable high-conductivity solid over anything dispensed.
A note on the lightweight plate
For weight-constrained or high-altitude enclosures, our 1200 W/m·K graphene thermal plate (density 1.5–4 g/cm³, CTE 4–12 ppm/K) can be machined into a spreader that moves heat laterally to the fins far more effectively than an aluminium part of the same mass. See the thermal plate →
Get a sample cut to your footprint
Send us your power level, mounting pressure, gap range and target thickness. We die-cut samples to your drawing and ship worldwide from Ningbo — sample lead time 7 business days. Request a sample →
Frequently asked questions
Does the pad survive thermal cycling from −40 to +55 °C?
The material is a solid graphene pad with no carrier fluid to separate or migrate. Our aging validation is 1,500 hours at 150 °C with thermal resistance drift held to 10% or less — a considerably harsher condition than outdoor cycling.
Can it replace the graphite sheet used as a spreader?
They do different jobs. Graphite sheets spread heat in-plane; a thermal pad conducts it through-plane across a gap. In radio units they are often used together — see pad vs graphite sheet.
Do you die-cut to our housing profile?
Yes, including holes and slots, supplied on release liner. Standard sheet is 150 × 150 mm.