Hi, Thanks for your message.

1. The main heat is from CPU, and the heat dissipation of other components is very small, so it is not necessary to put a heat sink on all the components.

2. If the heat dissipation is not achieve, pls check whether the heatsink had touched CPU.

Due to production deviation, a few heatsink may have errors and need to use 2 heat sink pads. If you encounter this problem, please use 2pcs thermal pads and stack them on the CPU of the CM4 module.

3. Pls remember to remove the protective film.

4. It is recommended to consider using CPU grease if need better heat dissipation.

Regards, Abby / Geekworm