Module ground/thermal pads

[WiFive]

The module datasheets say that soldering the ground/thermal pad on the bottom of the module is not recommended. What is recommended in terms of copper layer, soldermask, etc?

[jimbob]

We're about to send a PCB off, so if we could get an official answer on this it would be really useful please? (I know you must be busy at Espressif). If not, could you share the reasoning for the data sheet saying not connecting it/pasting it -- so we can best design to ground (or not ground) it, thermal conduction etc.

Thanks

[jimbob]

Hello again.

If there's no definitive answer, can anyone provide the reasons behind the recommendation of not soldering the ground pad in the datasheet?

Thanks

[mustafacc]

I'm interested in confirming this as well. Most modules with thermal pads are usually mounted on exposed copper and I assume this would be the case for the ESP32.

[ESP_Angus]

I spoke to some of our hardware engineers about this.

The note in the ESP-WROOM32 datasheet stating that soldering the base pad (39) is not recommended is a translation error. More accurately, soldering this pad is not necessary. The datasheet will be updated.

If the pad is soldered then it should be soldered to Ground. If soldered then the ESP32 will run a little cooler due to heat sinking into the main board. However, this is not necessary for adequate thermal performance (for example, all the current generation development boards with ESP-WROOM32 have a solid solder mask layer under the thermal pad.)