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SMT electronics assembly manufacturing forum.


Silkscreen/Legend on Pad

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#52977

Silkscreen/Legend on Pad | 19 December, 2007

Hi,

I was just wondering what the most common process is for silkscreen/legend removal and/or rework?

Scenario: Fab house had a registration issue on some SOT-323 packages where the silkscreen encroached or was actually printed on the surface pads jeopardizing the heel fillet acceptability.

Is there a solution that will remove the cures silkscreen without harming the soldermask and/or surface finish?

We'd like to re-work them if possible in-house (at least get the silkscreen off the pads). That way we don't lose valuable time shipping boards back and forth.

(If it matters the surface finish is ImAg @ 5um in thickness and the silkscren has been cured.)

Thanks.

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#52985

Silkscreen/Legend on Pad | 19 December, 2007

Naw, your legend is cured epoxy that's not going anywhere. There's no magic solution that will correct the mess you've made [found yourself in]. Use a sharp xacto-like knife to scape the legend off.

People should have noticed and corrected this before it got to you. * Board layout-person bears primary reponsibility and should reimburse you for your labor. * Your board fabricator should have noticed this also and brought it to your attention. He / she will laugh at you if you try to get compted for your labor.

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#52991

Silkscreen/Legend on Pad | 20 December, 2007

I figured as much. The exacto method is what we've been doing. We did send some back to the fab house and they really "fubar"ed the pads. So we decided to do it ourselves.

You are exactly right... it should have been caught before it ever made it to me.

Reimbursements aren't my department, but I am sure something is being discussed.

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