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Removing extra gold bleeding from pads

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#67923

Removing extra gold bleeding from pads | 9 January, 2013

Hello, We are having issues to solder components. We investigate the issue and found that the pads were having extra gold on the sides. Is it normal? Can we remove this gold 'bleeding from our PCB?' Thanks

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#67924

Removing extra gold bleeding from pads | 9 January, 2013

Not exactly normal, I don't think. Though I have seen similar in the CM world.

I can't think of a way to remove that overplating, either. If you can't reject the boards outright, then you might be looking at some touch up work, should bridging happen when you reflow the board.

Obviously if you are going forward with these, you have to pay CLOSE attention to your Stencil alignment when printing, and the component alignment after placement,and that will give you the best chance at success.

Good Luck!

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#67927

Removing extra gold bleeding from pads | 10 January, 2013

It appears the gold bleeding spans the gap between the plates, is this correct, or is it just the picture? If so, it should definitely be removed. Please clarify on what we are looking at.

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Pete B

#67928

Removing extra gold bleeding from pads | 10 January, 2013

Looks to me like under etching of the underlying copper and the gold is just plated to all of the exposed copper surface.

Is this characteristic the same on all solderable pads?

You will not be able to remove this gold.

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#67938

Removing extra gold bleeding from pads | 15 January, 2013

We would agree with Pete B about both the under etching as a possible issue and you will not be able to remove this gold. Another possibility is the solder mask (plating resist) hasn't been taken right to the edge of the pad.

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#67941

Removing extra gold bleeding from pads | 15 January, 2013

Hi Samuel,

The issue your seeing is caused by lack of control of your board shops Immersion gold plating line. I would reject the order back to them. Their gold line baths need to be checked or they had a poor rinse after nickel plate before adding enig. Check to see if this is an in-house process or outsourced.

Regards, Boardhouse

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