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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.




wetting | 10 March, 1998

What does the term "poor wetting" mean as a defect code ?

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Earl Moon


Re: wetting | 11 March, 1998

| | What does the term "poor wetting" mean as a defect code ? "Poor" should mean unacceptable when surface (component or PCB solder termination areas) wetting does not provide acceptable solder joints. Unacceptable wetting of PCB solder termination areas (SMT pads, as an example) are determined after HASL, or other solder coating processes are effected, after solder sample testing, or after soldering operations. Unacceptable wetting of component soder termination areas is found during solder testing (wetting balance, as an example) or after soldering processes. Industry has not clearly defined the extent or amount of unacceptable wetting. For me, non or dewetting exceeding 5% on a given solder termination area is unacceptable. Industry clearly has defined unacceptable wetting concerning solder joint formation.

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Luis Vazquez


Re: wetting | 18 December, 2001

Is the Sn% of the plating of the pin related to wetting quality?. I am having issues with one IC maker where some pins are OK and one or two pins are not soldered, even when there is weeting evidence underneath the pin. I am blaming the %Sn too high (around 90%) causing this issue. Other chips don't have this issue. Thanks a lot for your comments. Luis M. Vazquez

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Re: wetting | 18 December, 2001

Look here:

As an aside, please start a new thread when you have a new question, rather than resurrecting old [closed] threads like this one from 1998.

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