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Ink marking under conformal coating

Views: 3965

#66717

Ink marking under conformal coating | 2 July, 2012

We are having a problem with inspection markings on our boards running when conformal coating is applied

We have tried standard permanant markers, and also paint markers, but both run when the coating is applied.

There must be someone out there who has solved this problem already.

Thanks

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#66720

Ink marking under conformal coating | 2 July, 2012

It'll probably help to know what type of coating you're using on your boards, how it's being applied, and how it's being cured.

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#66722

Ink marking under conformal coating | 2 July, 2012

We are applying a SR conformal coating via aerosol.

Both permanent marker and paint pen are running as soon as the spray hits it

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#66724

Ink marking under conformal coating | 2 July, 2012

This material contains acetone in 30% plus range and toluene with this solvent combination ink is not an option. You will have to get a CC that doesn’t contain acetone as solvent.

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#66733

Ink marking under conformal coating | 3 July, 2012

Unfortunately our customers expect this coating on the boards so that is not an option.

There must be something that can mark underneath without washing off.

The silk screen doesn't wash off

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#66734

Ink marking under conformal coating | 3 July, 2012

Unfortunately our customers expect this coating on the boards so that is not an option.

There must be something that can mark underneath without washing off.

The silk screen doesn't wash off

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#66737

Ink marking under conformal coating | 3 July, 2012

Check with the coating manufacturer and see if they can offer a solution.

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#66738

Ink marking under conformal coating | 3 July, 2012


Lou

#66756

Ink marking under conformal coating | 5 July, 2012

What is the specific make/model of the SR? Being in an aerosol, I'm sure they thin it down quite a bit so that thinner is what is attacking your ink.

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#66824

Ink marking under conformal coating | 16 July, 2012

I have found that Edding do an aerospace marker, which is water based and does not run with the conformal coating.

However, this washes off prior to the coating so it is not much use.

Looks like we are just going to have to put some clear tape over the inspection labels prior to coating

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#66845

Ink marking under conformal coating | 18 July, 2012

We use the Edding pen as stated but then apply a quick set epoxy resin over the top and allow to dry, this does work.

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#66846

Ink marking under conformal coating | 18 July, 2012

How are you applying the expoxy resin?

Why use the expensive pen edding aerospace pen under the epoxy when a cheaper pen will do?

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#66862

Ink marking under conformal coating | 23 July, 2012

mccabekev,

How are you applying the mark? Can you scribe the board?

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