You can stop pink ring further up-stream in your process. You could use a "Post Reduction Oxide". This type of process, when run properly, will eliminate pink ring all together. This way you are not band-aiding a situation that potentially can get out of control and cost you time and money in other processing issues. For example, like mentioned in the reply below, you tend to harden the epoxy of the hole wall making it harder to remove. If you are not careful during your bake you can ruin the material properties in the hole causing plating issues down the process. The best recommendation is to eliminate the problem. Todd Campbell Gerber Systems ---------- From: TechNet-request To: TechNet Subject: Re[2]: Post Baking Process Date: Monday, January 27, 1997 12:30PM Will someone please clarify the paragraph below ? It states that pink ring can be eliminated with a post drill bake. It then goes on to say that it cannot reseal the crack and it is only a cosmetic fix. Isn't pink ring a cosmetic issue? Why would it be a dangerous fix if it works?? Also, you can have the best innerlayer treatment out there and if the drilling operation is unoptimized, it will not make a difference in cracking of inner layers. ______________________________ Reply Separator _________________________________ Subject: Re: Post Baking Process Author: [log in to unmask] at corp Date: 1/27/97 11:46 AM Post-drill bake - A bake after drill has been shown to eliminate pink ring. Our work shows this is a dangerous fix. Pink ring is caused by a chemical attack on innerlayer surfaces that are exposed by cracks introduced at drill. The bake relaxes the epoxy enough to close the crack, but it cannot reseal the crack. Thus it is at best a cosmetic fix. However in addition, the bake hardens epoxy smear and makes it difficult to remove. A much better solution to pink ring is to use a good innerlayer surface treatment that prevents cracking at drill. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * 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 unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * 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] * ***************************************************************************