In order to realy identify the true cause of your seepage issue, I would recommend you look at some resist side wall S.E.M.'s. This will help determine at the micro level what you have for resist at the foot where it is seeping from. Any negative resist foot on a 4/4 feature could result in lifting in the soap cleaner in pre clean as well as in pre clean to Solder plate. X sections of a copper/solder plated panel before resist strip would also help identify this. I would assume that you have already verified that you have done water break test on pre cleaned panels before resist lamination and all on that end is in spec. ie. Roll pressure, Roll temperature, exit temperature etc. As you know MLB lamination will follow the topo of the inner layers to some degree. Asking the laminator to apply resist with good contact can only go so far, you may try running a thicker film as a band aid just to find what will fix the problems and work backwards to eliminate it. We resist laminate some pretty non uniform surfaces and have seen some of this ourself's in the past. [log in to unmask] On your multilayers, do you use <copper> foil lam or core <double sided> construction? If you use core construction you may want to check into how well you remove/clean the outer oxided surfaces before electroless copper. Also check the copper surface before image. Tape test. If you get toooooo much e-less copper coming off then there's your adhesion problem. Groovy ______________________________ Reply Separator _________________________________ Subject: Disscussion on seepage /resist lifting problem in 4/4mil and Author: [log in to unmask] at SMTPLINK-HADCO Date: 9/9/96 8:56 AM with respect to above mentioned problem i wud like to clarify that the said defect is being noticed only in ML boards.The said problem is not noticed to such an extent in DOUBLE SIDED RIGID boards for the same complexity of the Product. Therefore we suspect strongly the ML lamination process as a POTENTIAL CAUSE.Could any one throw some light on this *************************************************************************** * 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. * *************************************************************************** *************************************************************************** * 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. * *************************************************************************** *************************************************************************** * 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. * ***************************************************************************