PCB traces showing

MCF 76

Vice's Love Slave
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Jan 21, 2010
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Hey guys,

After cleaning some of my pcb's this week I noticed on one particular board that the green coating has come off on a few of the small traces. Should this be coated with something to protect it? Never seen this happen before but after you clean 15-20 bound to run into something new.

Searched a bit about traces showing and how to protect it. Looks like i need to just get a spray can of "conformal coating" clear from a local electronic store. There are like 3 maybe 4 spots showing on the back of this pcb. I just got done cleaning it so going to let it dry all night and tomorrow go get a can of that stuff. Might as well mask off board and spray the whole back side since there are several spot showing.

Anybody mess with this stuff?
 
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drmadd220

n00b
Joined
Feb 8, 2006
Posts
43
Hey guys,

After cleaning some of my pcb's this week I noticed on one particular board that the green coating has come off on a few of the small traces. Should this be coated with something to protect it? Never seen this happen before but after you clean 15-20 bound to run into something new.

You should get an overcoat pen and cover back over those. You can find them on amazon, like the one from MG chemicals. They run about $10 to $15.
 

MCF 76

Vice's Love Slave
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You should get an overcoat pen and cover back over those. You can find them on amazon, like the one from MG chemicals. They run about $10 to $15.

The "acrylic" type should be plenty good enough you think? The other types are a bitch to remove like polyurethane etc.
 

ChuChu Flamingo

We have purposely, trained him wrong, ...as a joke
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One has to be careful when cleaning arcade boards. Just the simple act of cleaning can remove the clear coat, but even more so rubbing alcohol removes it with great ease.

I've noticed this on a few cartridges before in one spot where the conformal coating is missing and it seems to me to just be a quality control issue/probably due to age.

I would definitely try the pen, spraying seems like a bad idea as it harder to control where it goes unless you mask the board.
 
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MCF 76

Vice's Love Slave
10 Year Member
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One has to be careful when cleaning arcade boards. Just the simple act of cleaning can remove the clear coat, but even more so rubbing alcohol removes it with great ease.

I've noticed this on a few cartridges before in one spot where the conformal coating is missing and it seems to me to just be a quality control issue/probably due to age.

I would definitely try the pen, spraying seems like a bad idea as it harder to control where it goes unless you mask the board.

This board I'm working on looks to me it was a quality issue with it also. Because there is some small dots on the back side on one of the corners where the coating looks like it never adhered to properly. The OG coating looks to be poorly applied compared to all the other boards I've looked at. Almost has a brushed look instead of the slick blemish free look all the others have. I also noticed after cleaning that it has been touched up before by a pen. You can see the build up of it in certain small areas. The top side however is perfect no traces showing at all. So this was the only board I have that had these issues thank god. The game worked fine before I cleaned it lol hopefully it will once I get it back together.
 

ChuChu Flamingo

We have purposely, trained him wrong, ...as a joke
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Makes me wonder if it was applied by hand hah. Usually it is sprayed evenly, but you never know.

It isn't a major catastrophe if a trace is showing though unless you live in a humid place. With this in mind however, it is a good idea to cover it just to protect it from potential tarnish/scratches depending upon your storage conditions..
 
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brizzo

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Jun 9, 2017
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Can you post some photos of the solder mask defect? Perhaps there is more to the story we can identify before re-sealing
 

Xian Xi

JammaNationX,
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Use a non-metallic green or matching color nail polish. Clean the area first with some IPA. If the trace has rust on it or corrosion then use a fiberglass pen to clean it off first before the IPA.
 
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