"Tempea, Ioan" wrote:

> Hi,
>
> now that the problem with the blistering solder mask is fixed ( we sent the
> boards back since backing them was of no use), I have another one.
>
> Some of our assemblies have a high density of VIAs. On these products,
> pretty often we get after wave some solder bubbles over the VIAs, some of
> them exploded, like degassing. Since on some we see the same bubbling even
> on the fiducials, I wonder if the humidity is the only one to blame, I even
> wonder if there's any issue related to humidity at all.
>
> So, what could it be? Incompatibility between flux and solder sounds
> possible?
>
> I would appreciate any input,
>
> Ioan

Dear Ioan :

To me it sounds like copper plating problem. The surface of the base copper
probably was not cleaned enough, it caused blisters. I think if you do a tape
test after copper plating, probably, copper plated will peel.

Please correct me if I am wrong!!!

Francis

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