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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

DEK Pump Print Process

John S


DEK Pump Print Process | 21 October, 2002

We just started using DEK's pump print process on a high volume SMT line. We are using Hereaus 955. It works well for most components, but we have an issue with missing/partial glue dots on large diameter deposits (0.050"). The stencil will be completely empty in the problem locations, and the glue will appear to have air pockets in the head. We've contacted DEK, but they haven't been able to solve it. We just end up tweaking it all the time. Any advice from someone using this newer process would be greatly appreciated. Thanks John

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DEK Pump Print Process | 21 October, 2002

Try a "cross" design across the problem apertures. So you wind up with 4 smaller deposits on the PCB (instead of 1 big one) but should be enough to hold the component. It worked for us and was much easier on the blades (they kept catching on the far edge of large apertures).

good luck, pr

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DEK Pump Print Process | 23 October, 2002


Try Dek (S'pore) new design call "vector frame", no metal frame.


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Alan Hobby


DEK Pump Print Process | 30 October, 2002

Don't print too fast (<2"/sec) unless the glue is warm (28C+?) to reduce viscosity and so prevent skips. Print with a "snap-off" gap of 2 - 5 mm. This allows any air at the bottom of large apertures to escape, rather than compressing and bouncing the glue back out again. Use a closed head system (ProFlow) to ensure good aperture fills, or use PumpPrint squeegees (with a flat rather than a sharp edge) to seal the top of the apertures and prevent glue escaping behind the squeegee, rather than going down the hole. In desperation, make 2 squeegee strokes per board.

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