Hello Frank

had what looks like the exact same thing a few years back

happening predominantly or exclusively in small vias ?

our problem was airbubbles in the holes, preventing circulation and plating

fixed this with mechanical agitation.

good luck / Wolfgang

> -----Original Message-----
> From: Frank Freitas [SMTP:[log in to unmask]]
> Sent: Friday, October 29, 1999 11:04 AM
> To:   [log in to unmask]
> Subject:      [TN] Tapered Voids
>
> I'm looking for some information on the causes of tapered voids and how to
> eliminate them from the PWB manufacturing process.
>
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