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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Less solder with fine pitch qfp

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#56734

Less solder with fine pitch qfp | 29 September, 2008

We r facing less soder problem with qfp,using 4 mil tencil and lead free paste,tried out different combinations of reflow profile,can anybody suggest?

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#56741

Less solder with fine pitch qfp | 29 September, 2008

Let's narrow this down. Questions are: * Are you putting the proper amount of solder in the board with your stencil print process? * If you are putting the proper amount of solder in the board, where is the solder going?

Pick one and then fill-in the blanks to bring us upto speed.

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#56756

Less solder with fine pitch qfp | 30 September, 2008

What pitch? You can go 5 mil or even 6 mil stencils depending on your screen printer.

Also what do you consider "less solder"? What defect are you having. Remember on a QFP you use the heel filet to determine proper solder joint - not the toe.

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#56790

Less solder with fine pitch qfp | 2 October, 2008

We had similar issues until we went to a 6 mil stencil thickness.

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