anovickis , 05-31-2019, 12:44 PM
There's the dip method for applying conformal coating, and the spray nozzle on an x/y table, or there is also the spray can
there's also a variety of materials to choose from that have varying thickness, cost, and resistance to various elements in the environment (solvents, moisture, water, salt, temperature, etc)
some materials set in a few minutes, and some take 24 hours to harden
For some boards you can dip, others that have connectors it's not desirable to coat the connectors.
From what I see there is a DXF file that's supplied with data for
1) areas that must be coated
2) areas that must not be coated (electrical or optical connectors, certain sensors, etc)
3) areas where it does not matter if coated or not
IPC-830 covers coating types and guidelines
IPC-850 covers potting
(sorry I can not post those here)
Some coatings lend themselves to rework, and some are harder to rework.
Additionally some coatings are used to understand if a board was tampered with after assembly (usually this is the thick black stuff, whereas the environment barriers are clear)
My question is more of - this specification could be done on a "mechanical" layer in altium/etc, but everyone seems to do this as a separate (DXF) drawing
And, I'm not sure why that is exactly
I suspect it's a an "80x24" thing that hasn't advanced to current tools