We found that a reduced oxide helped quite a bit. This means that the inner layer processing is involved in the formation of wedge voids. I'll bet that lamination cycles can adversely affect the boards too. Drilling is, of course involved, & wet process brings out the defect. What problems do you have with reduced oxide? Matt Byrne HADCO-Owego ______________________________ Reply Separator _________________________________ Subject: Re: Mechanism of Wedge Void Formation Author: [log in to unmask] at SMTPLINK-HADCO Date: 7/15/97 06:37 AM wedge voids are usually a start of shotty drilling - then seepage of solution through the voids and that solution then starts attacking oxide layer - which inturn leads to pinkring. Dm will not make a difference - actually if drilling is still primary cause - will be the same or worse - since Dm is thinner coating. A reduced oxide layer can eliviate problem to a certain degree - but then - reduced oxide brings in a problem of it's own. regards Richard Fudalewski Atotech Canada *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************