Copper shim between the SoC and the shell
A ~3 mm copper block bonded to the BCM2711 so a 0.5 mm pad can bridge the remaining gap, adding thermal mass.
What it takes
- Disassembly
- Purchase required
Difficulty 2 of 3 — moderate.
Details
Planned as a roughly 30 mm-square copper shim bonded to the SoC with thermal adhesive, leaving a 0.5 mm pad to contact the back shell; the thread also discusses padding the RAM and the small Broadcom chip under the same shim.
It is a design discussion with measurements rather than a finished, benchmarked build, so treat it as an approach to copy with your own gap measurement.
Links
Open at Forum threadRelated mods
Two layers of 0.5 mm thermal pad and a small aluminium heatsink on the CM5 SoC, held with thermal tape — about 10 °C cooler under load.
A CM4 socket protection adapter lifts the CM5 so a 0.5 mm pad reaches the back shell instead of the thick stock pad.
Replace the ~4 mm stock pad, which is sized for the A-06, with a thinner high-quality pad or paste that matches the real CM4/CM5 gap.
A 40-pin FPC ribbon from the mainboard's GPIO connector to a breakout board gives a fan its 5 V and ground inside the case.
hack2you's machined cooling pad for the compute module, sold on Tindie alongside the trackpad keyboard and NVMe modules.
Replaces the metal back with a printed cover that holds a 30 mm fan, a heatsink and a flat 10,000 mAh pack in place of the 18650s.