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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


poor print definition

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mark

#39826

poor print definition | 20 February, 2006

Hallo all,

I have recently had possibility to work with DEK265. I have met with problem poor print definition (no sharp edges). I used stencil 150 thickness, metal squuegees. I moved than the same stencil, squeegee and parameters to DEK nifinty and the print was very good. What can be the problem and what should i correct. All calibration high squeegees ware done.

Regards MArk

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#39830

poor print definition | 20 February, 2006

We assume your stencil is clean. So, try: * Reduce stencil separation speed. * Reduce squeegee pressure. If the pressure is not proper, excess number of particles are stuffed into an aperture and inner pressure / friction among particles increase, and consequently makes smooth release of solder paste difficult. * Improve board support.

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Chunks

#39838

poor print definition | 21 February, 2006

Hi Mark,

Not to be condescending, but is your 265 camera in focus? I've seen one instance of this.

If it�s not the camera, and you are sure all your other parameters are good, , then poor definition can be from bad snap-off or bad gasketing. Snap-off should be easy to check for. Run boards at different setting. Bad gasketing can be attributed form several different things. Check your clamps on your 265. Make sure they are in good condition and not damaged. If damaged they can cause the stencil not to gasket the board properly. Are you using an vacuum assist? If so, your vacuum can pull past the gasket and give you a a bad definition of paste.

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mark

#39886

poor print definition | 22 February, 2006

Hi,

We are not using vaccum caps. The support pins for both printers is the same ande cover all board (components only on Top side of the PCB). I will check snap-off (right know setting 0.2-04. mm/s). I also suspected poor gasketing but clamps are ok. No damge looks ok.

Thank you

Mark

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