Steve: Wadja mean "I fixed it, now tell me what I did to fix it." Steve, you�re one scary guy. ;-)
"Steve�s Longer Pad Theory" - Stubby pads will not make solder flow-up the leads of a QFP100, leaving sparse solder on the pads. Given a choice, solder would prefer not to defy gravity and climb the lead. It would prefer to form big ugly blobs and then if forced to, form a kinda spread-out blob, shorting the leads on the QFP together.
"Steve�s More Balanced Thermal Mass Below The Joint And An Increase Of The Affect Of Surface Tension Theory" � I like the "More Balanced Thermal Mass Below The Joint" part, because that balance keeps all the contact surfaces the same temperature and provides for a nice even solder flow. � But I�m not sure what the "An Increase Of The Affect Of Surface Tension" part means. The flux reduces the surface tension of the solder, but it should be doing that ... ?
"Steve�s Unspoken Theory Of Corrosion On The Pads That Limited Solderability" - We assume this was hypothesized, but never postulated, because pads other than the QFP100 soldered well.
Go get 'em
Dave F
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