Dear Colleagues,
I´m working in the aerospace industry at INVAP SE - ARGENTINA and my
rol is QA Electronic Service Manager.
Would like to know your comments on following matter:
 
Have requested to a new PCB provider some HASL plated pcb specimens in
order to verify its quality and found out what enclosed pictures show:
100% of plated pads have its plating drained or slided off toward the
same direction from left to right affecting coplanarity.
As per our visual inspection at first conclusion we stated that it is
an Indicator Process (not necessary dewetting related issue) and could
be caused between others, from:
1) Pb % degraded.
2) Low air flow temperature trend.
3) Angle of impact of air flow.
 
We asked the provider to define cause of this issue. We didnt do a
metallographic analisys to verify Cu6Sn5 presence to confirm
intermetallic fusion.
 
We run the J-STD-003 test "C" to verify solderability and it is 100% Ok
well wetted, furthermore we soldered a desoldering ribbon (previously
tin plated) directly to a pad without using of Flux nor solder and
verified that its adherence is very good which indicates pad surface
would be well plated.
 
As per your experience: Do you agree with us on our conclusions
specially that it seems to be not a strictly dewetting matter?
 
Appreciate too much your feedback on such a matter.
 
Brgds, Ricardo Moncaglieri





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