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Stencil Inspection

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#63951

Stencil Inspection | 17 March, 2011

We inspect incoming stencils to see if they are labelled properly and sometimes check the width of special apertures and that's about it. We want to kick it up a notch. What are others out there doing to inpect incoming stencils? Is there criteria or guideline that would help us?

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#63957

Stencil Inspection | 17 March, 2011

> We inspect incoming stencils to see if they are > labelled properly and sometimes check the width > of special apertures and that's about it. We > want to kick it up a notch. What are others out > there doing to inpect incoming stencils? Is > there criteria or guideline that would help us?

Hi, We could produce stencils,however,we produce stencil based on the gerber file,if the stencils match with the gerber file,then i can work.

lenne

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#63981

Stencil Inspection | 21 March, 2011

At incoming inspection we visually check the stencil against the gerber file (called up on the computer monitor) used to produce it. This is mostly to check that they mirrored the bottom side correctly although we check the top side as well. That is about all we do.

Why do you want to kick it up a notch? Have you been having issues with some stencils not being manufactured correctly?

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rem

#63983

Stencil Inspection | 21 March, 2011

We really don't go over board with stencil inspection either. I normally send my files to the vendor, they size and provide me with a check plot. I will verify everthing is oriented correctly and panel fiducials are in place. That's it. I don't know what you could inspect other than that. Cutting quality this day and time is always very clean and accurate.

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#63992

Stencil Inspection | 22 March, 2011

At times, yes. We do high volume, fine pitch on flex panels and if we need a 8 mil width aperture, it can't be 9 or 7. It has to be 8 and we have seen times where the tolerance is +/- 1 mil. Additionally, we have received stencils with abnormally rough sidewalls. I don't know what the tolerance is on a laser cutting process nor am I certain we can reject for saying it's "rough" on the sidewalls. I was hoping there was some guidelines to inspect to. We never had much trouble with class 2 builds with average difficulty parts. Class 3, fine pitch on flex panels is very tough so here comes the need for tighter stencil control.

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rem

#63998

Stencil Inspection | 22 March, 2011

I've never done flex boards so I cant't say what tolerances you would need to maintain. Does you stencil manufacturer provide a QA data sheet with your stencils? If so I would specify to them the critical apt sizes in areas and push it back on them to show you the data when you get your screens. I've looked for guidelines but can't find anything that would help you with the edge finishes.

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