Earl Grey is a good tea, I agree,
Now, Joan, are you sure it's about cold soldering at all? As you describe it could as well be dewetting. If it's dewetting, your trouble shooting can leave the wavesolder for a while. Again, I wonder why you don't do a wetting test on the terminals.
Good Lunch
Ingemar Hernefjord
Ericsson Microwave Systems

----------------------------------------------------------------------
Earl and all,

the soldering was a lot better before. We've always had the QA on our back,
checking the flux density and the settings for the problem assemblies.
Myself, I don't recall having seen so much cold solder.

The machine had been calibrated last saturday during the monthly
maintenance, when the pot is thoroughly cleaned.

It's possible that the solder mask changed, since it's darker now. Together
with the soldering problems we started experiencing discoloration of the
solder mask on the solder side. But wouldn't this randomly affect any place
on the surface? I still get the connectors OK, with bad solder joints on the
caps and resistor networks.

There has been no artwork change. However, could some changes in the
materials or manufacturing of the board affect somehow the thermal mass here
and there? I mean, maybe the connectors drain somehow the heat from the
adjoining components.

And anyway, what on earth generates cold solder in the waving process?

Ioan

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