Does any one know if the smôl ESP32 product be encapsulated in a small plastic enclosure with potting compound without harming proper operation?
Hi,
Short answer, no, but only because I’ve never tried it. The smôl boards were designed with encapsulation in mind but we’ve never actually tried it. We were going to leave that part to the experts who have (e.g.) developed whale-tracking darts previously.
However, some thoughts that might help:
Are you encapsulating only the ESP32? Or will it have other smôl boards connected?
If you have another board connected, I don’t really know how the FPC connectors will respond to encapsulation. Can the epoxy creep right into the connector and make the connection problematic? I don’t know. I’d recommend putting a small piece of tape over the connector-FPC ‘junction’ to prevent epoxy ingress.
Will you have USB connected? The USB connection should be tight enough to prevent epoxy ingress.
How will encapsulation affect the WiFi antenna? I don’t know. If you can spare the time, maybe try encapsulating only the area around the antenna to see what happens.
What kind of potting compound do you need? Are you potting this so it can be submerged in water? Does it need to be able to withstand pressure? If not, then maybe a softer rubber would work. Which could be peeled off again if everything stops working. It was a long time ago, but I did have some success with Raytech Magic Rubber - a two-part ‘soft’ potting compound.
If you only need to provide a moisture barrier, I can recommend Electrolube Acrylic Protective Lacquer (APL). It comes in 15ml bottles and in larger quantities. I’ve been using it for a long time and on many high-altitude balloon missions.
Do not use silicone sealants or anything else containing acetic acid. The acid does very bad things to circuit boards…
I hope this helps!
Paul
Thanks for the reply. The intent would be to encapsulate just the ESP32 center section as a means of “secure mounting” in minimal space. IP65 would be the target; no need for submersible. The USB connection would somehow be isolated from the potting compound. I was intrigued by the smol 
size and was thinking about how it may solve a size constraint I have for an application I’m working on. Also, thanks for the tips about what materials to stay away from. I had a pretty good idea what not to use and was considering trying it with a 2-part electronic grade potting compound (exact spec TBD). I’ll past back if I get time to try this.