Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Printing smear

Tracy Guo

#8236

Printing smear | 10 December, 1999

Hi, I'm facing smear after printing on DEK288 using reverse squeegee at the edge of panels. I've checked the fixture, printing parameter, stencil, solder paste. What else can I do?

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#8237

Re: Printing smear | 10 December, 1999

Tracy,

I would check the squeegee blade for wear at the edges. Also, check the squeegee pressure to ensure it is not to high, forcing the paste between the stencil and the land, causing a smear. Good luck.

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cb

#8238

Re: Printing smear | 15 December, 1999

Tracy,

Gary made some good points, you could also to check to see if you have the printer taking a long enough stroke over the board. I have seen some people not have the squeege come across the board enough and the paste roll is still setting over the apertures. This can casue a little smear.

Good luck, CB

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Stefan

#8239

Re: Printing smear | 16 December, 1999

Check the print gap and check the clamp edges, sometimes the clamps is damaged causing a distance between the PCB and the screen.

Good luck

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