why the antenna is damaged of ESP32-WROOM32

[andrej32]

The ESP-WROOM-32 module is installed on a Board of FR4 with a thickness of 0.5 mm. When installing, all the recommendations of the documentation were observed. There were cases of ignition of this module in the antenna area. Why is this happening and how to prevent it?

[ESP_Sprite]

Can you tell us a bit more about where this is installed, plus a few more details about e.g. the PSU?

My personal guess is that something arced over to the antenna. Effectively, from a DC point of view, the antenna is grounded, so it would be more-or-less a good point for the arc to go to. Also, if you look at the splatter pattern of the carbonization, this makes sense whatever happened must have happened above the ESP32, because otherwise the metal shield would have shielded certain parts of the PCB from being coated, and you can also see the top of the shield is affected as well.

Whatever it was, it must have been quite a current that ran through the little antenna. I think the trace is 2mm or so, and from memory the copper is 1oz. That trace should be able to carry 1 amp without heating up, and many more (10 at the very minimum would be my guesss) to explode in a spectacular fashion like you showed. Given that the antenna trace is a 'dead end' at that location, I think it's highly likely something external is in play here.