I whole-heartedly agree with you. Wet process can be the cause of pink ring, but it is also highly probable that something abnormal happens during lamination/drilling, causing the pinkring/wedgevoid formation. The reason people usually look at the wet processes when pinkring occur is because the wet processes "BRING OUT" the defect. If the oxide is not reduced or is not allowed enough time to be reduced, the next thing is that the acid resistance test fail misarably, and every hole comes out of SES will be pink. The oxide reduction is one major variable in wet processes that will cause wedgevoids. [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Re[2]: Mechanism of Wedge Void Formation Author: [log in to unmask] at corp Date: 7/15/97 2:11 PM 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] * *************************************************************************** *************************************************************************** * 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] * ***************************************************************************