When to use "PVB 16 Varnish"

[nardev]

Should every PCB that is manufactured and installed in not very protected enclosures, be coated with "PVB 16 Varnish" spray?

Is there a situation when you would not use that?

Does those PCBa facilitates offer PCB ultrasonic cleaning and coating PCBs with "PVB 16 Varnish" after manufacturing? I never saw that as an option.

What would be expected of a device which is installed mostly indoor but usually in a wall or some other plastic enclosure.

Thnx

[wraper]

Why you are so fixed on particularly "PVB 16 Varnish". It's just a conformal coating made by so-so Polish manufacturer. Is it a good idea to use conformal coating when PCB can be exposed to harsh conditions.

PCBa facilitates offer PCB ultrasonic cleaning

Most likely it will be cleaning without ultrasonic.

Is there a situation when you would not use that?

Depends on PCB. If there are a lot of switches or connectors or whatever what should not be exposed to it, then conformal coating becomes troublesome. Also generally you cannot wash switches.
BTW don't forget that each additional manufacturing step results in increased price and manufacturing time.

[nardev]

Why you are so fixed on particularly "PVB 16 Varnish". It's just a conformal coating made by so-so Polish manufacturer. Is it a good idea to use conformal coating when PCB can be exposed to harsh conditions.

PCBa facilitates offer PCB ultrasonic cleaning

Most likely it will be cleaning without ultrasonic.

Is there a situation when you would not use that?

Depends on PCB. If there are a lot of switches or connectors or whatever what should not be exposed to it, then conformal coating becomes troublesome. Also generally you cannot wash switches.

Ah, i didn't now exactly how you say that in english. I knew only that brand.

Ok, what could be a problem with relays or so?

[wraper]

Ok, what could be a problem with relays or so?

Some relays can be washed but generally no. Also even sealed relays often have breathing hole which is initially covered but then should be opened by breaking off plastic protrusion. Failing to do so will result in decreased endurance. Even if you don't wash PCB, clogging small breathing hole with varnish is not good.

[nardev]

So, can we say in general, if it is possible, it would be good to cover all the boards with the coating and that's about it. And to be careful about some components.

?

[tooki]

Um, no.

There are good reasons why the vast majority of PCBs are not com formally coated. Like cost, lack of need, and how they make repairs much more expensive. Conformal coating is really only used in products used in harsh environments.