I found out today that the Sharp distance sensor 10 cm carrier with soldered sensor is not conformal coated. If the back happens to contact some piece of metal (such as a Zumo blade) then it may short out the sensor and destroy it (or, more likely, some component on the carrier board.)
Thus, I recommend putting a piece of tape across the back of this board after you’ve soldered the 3-pin headers in, just to be safe!
Question for our Pololu friends: Do your carriers/boards generally specify conformal coating, or is this a general caution for your products? I can’t find a mention one way or another on the product pages.
Our boards are not conformal coated. I do not know of any products generally like ours (e.g. Arduinos, stuff from Parallax, Adafruit or SparkFun) that are conformal coated; do you?
My Arduino Uno boards seem conformal coated. I gotta press pretty hard with a probe to get through to measure on the back of them. Maybe that’s just oxide :-/
I like this coating, because I can put down the board on my workbench without worrying about exactly what’s beneath it I have a bottle for my own boards, and I’ll just make sure to brush it on other boards I get. For those who don’t have this option, scotch tape is second best.
For hobbyist gear, it might be a nice addition in robustness to add this. No idea what it would cost at mass scale, nor whether Clark County would bill you as a chemical polluter if you started doing it, though
The way I see it, no failure is wasted if I can generate an improvement suggestion from it that would help someone else in the future!
I just looked at an Arduino Uno (and a Leonardo) and I’m pretty sure they are not conformal coated. I don’t know much about it, but my impression is that it wouldn’t make much sense not to cover all the SMT stuff and that the coating would be really obvious just by looking at the boards (and you wouldn’t be able to do any soldering or rework on them). But there must be all kinds of options, and stuff I’ve seen in the past might have been particularly thick.
I’m working on a reply to your comment on my blog.
Only coating the back would solve 90% of the cases IMO.
Re-work still works, as the acrylic stuff burns off at lower temperatures than solder melts.