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solder splatters

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#63989

solder splatters | 22 March, 2011

NEED HELP!!! I am getting solder splatters on my panels. We produce 100's of different kinds of product and this is the only one that is leaving solder splatters all over the masking. It is however the first time we have used 40 pin QFN's. I don't think that it is the oven, DEK, or panel as we produce products very similiar to these minus the QFN's. Could it be the stencil? I don't know. I am at a loss. Any help would be great. Thanks

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#63990

solder splatters | 22 March, 2011

Make sure the paper is advancing correctly on your stencil wiper. I have seen this cause major issues. If the paper hangs up, it will smear paste across the bottom of the stencil every time it wipes.

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#63991

solder splatters | 22 March, 2011

> Make sure the paper is advancing correctly on > your stencil wiper. I have seen this cause major > issues. If the paper hangs up, it will smear > paste across the bottom of the stencil every time > it wipes.

We are manually cleaning the stencil. While that is ok, we are now having to clean the stencil every 2-3 panels

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#64135

solder splatters | 8 April, 2011

A couple more things to look at. ( DEK) Check you wiper blades. This is the rubber blade that holds the paper in contact with your stencil. When these wear down it will not clean properly. Also make sure when you run this product that you verify that you are getting a good stencil to pcb seal once the table comes up to contact the stencil. If you are getting a gap then you are going to have print bleed out.

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