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Solder balls after wavesolder



Solder balls after wavesolder | 14 November, 2001

We are experiencing many solder balls after wavesolder. Two different board suppliers of the same board are involved. My initial reaction was that it was the process but in researching information in this forum I am beginning to wonder.

How can one (easily, I don't have access to Methylene chloride or ethyl acetate) tell if the solder mask is properly cured? And if it is not cured, would baking these boards finish the curing process and eliminate/reduce the problem?

Thanks in advance,


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Solder balls after wavesolder | 14 November, 2001

Not to worry. Just run the boards through the cleaner. It will remove all the solder balls. The gross filter on your washer will collect all the solder balls. Coo eh? ;-)

How to cure SM? Is your mask UV, er thermal? After learning the type, you can begin to talk about the cure. Each mask supplier recommends the peculiars for its products. [I�d expect to cure SR1000 at 300�F for an hour.] Why do you want to do this? If it�s blanked, get your fab to fix it.

Testing SM cure? Look at: TM-650, 2.3.23 Cure Solder Mask. Hey, ask your fabs to check the cure. They�ll have the stuff.

Lemme guess. What are the odds that your fabs are both: * Using the same solder mask? * Curing it improperly?

Nada, zip, goose egg, etc. {Yeth!!! He shoots. He scores.]

Listen. Most often, bare circuit boards see some harsh processes (ie, HASL, ENIG, OSP, etc.) in the board shop after the solder mask is cured. If the mask survives these processes without any degradation, lifting, adhesion loss, blistering, etc., then you can probably assume that mask has been cured properly.

As Britney Spears says: �It�s you!!!!� Just think about the things that are consistent. Your: * Process materials. * Wave soldering process.

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Solder balls after wavesolder | 27 November, 2001

We have noticed that when you are using a no-clean flux with the wave solder process that you will have additional solderballs. One thing that we have done is to change the PCB finish to a matte finish. This has greatly reduced the number of solder balls. I would speak to your board vendor about this. Hope this helps. Justin

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