I have built cavity type boards before; I understand the kinds of problems you are fighting. One thing I learned about cavity boards: be willing to try process steps that are "backwards" or out of order from the normal process. Sometimes, this is the only way to overcome some of the obstacles you're up against. What step in the oxide line is attacking the LPI? You may want to skip that tank, or perhaps reduce the dwell time, if possible. Or, have you tried other LPI's? There may be another product that will be better able to withstand the oxide chemistry. Also, examine your LPI process; maybe there is something you can do there (increase cure?, UV bump?) to help. Mark Dowding Regional Technical Specialist Insulectro 909-943-5758 [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] * ***************************************************************************