One possibility often overlooked is the physical damage to an oxide that can be caused by the initial closing of a press. Fortunately this can be evaluated by simply closing and opening the press and pulling the copper foil away from the pre-preg. In some cases, a severe transfer of the (black) oxide to the pre-preg can take place, the detached oxide can then flow with the resin possibly contributing to ET failures in final?. Some oxides are worse than others for this transfer effect. George *************************************************************************** * 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] * ***************************************************************************