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black fiducials

Views: 4716

#76450

black fiducials | 12 October, 2016

Hello everybody. I can't get black fiducials when laser-cutting a SMT stencil. They are grey or beige but never black. Can someone help me? Thanks!

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#76455

black fiducials | 12 October, 2016

I think stencil manufacturers back fill half etched fiducials with black epoxy or something. I know I've had some worn and that's what I've done for my vision systems to be happy again.

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#76458

black fiducials | 12 October, 2016

Yes, bottom-side fids are usually half-etched with epoxy fill. just the half-etch gives a pretty "dirty" looking fid.

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#76459

black fiducials | 12 October, 2016

OLD DEK manuals actually have a procedure for fiducial fill, and they used to sell a kit (for way too much $$$$); since usually pretty well covered by stencil vendors probably not on the list any more.

www.dekhead.com

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#76463

black fiducials | 13 October, 2016

Yes, I read about filling the fiducials with balck epoxy, but it was said that it doesn't last for long. Thank you for your reply.

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#76484

black fiducials | 20 October, 2016

Basically, what is the main issue which requires you to use black fiducials? Stencil mark recognition issues?

Solder printer machines have ability to adjust the brightness or contrast.

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#76487

black fiducials | 20 October, 2016

We get our fids laser etched and never have fid read problems. They are black. (see attached)

All of our printers are Momentums.

Half etch and fill is old school. I used to take 2 part epoxy and mix black printer toner into it and squeegee the mixture into the fids with a razor blade to fix them.

Attachments:

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#76586

black fiducials | 9 November, 2016

> Yes, I read about filling the fiducials with > balck epoxy, but it was said that it doesn't last > for long. Thank you for your reply.

They don't last for long? They should last forever. The fids are on the bottom of the screen. Why would they wear out/off?

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#76601

black fiducials | 16 November, 2016

Why would they wear off? Many people use ultrasonic stencil cleaners which will breakdown the epoxy over time and wash it away.

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