I would start with drilling. If the drill parameters are not correct (i.e. feeds and speeds) or if the drill quality is poor, the drill process may be introducing resin smear to the extent that the desmear process is not capable of removing it. If drill parameters are acceptable and hole quality is fine ( meaning no rough gouging or nail heading ) then the next place I would look is at the desmear process. Ed Cosper ABC ----- Original Message ----- From: "Smith, David V." <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, April 19, 2000 5:33 PM Subject: [TN] PCB question > A question for the PCB gurus: > > We have been receiving boards from a supplier that are exhibiting > separations at the interface between plated hole wall and internal layers > (a.k.a. interplane separations, post separations, interconnect defects) in > cross-section, after thermal stress. Specifically, the separations are > occurring between the electroless copper and electrolytic copper. Horizontal > cross-sectioning reveals that the location of the separations is consistent > from hole to hole. For example, in a grouping of holes viewed in horizontal > cross-section, the majority of holes will show the separation extending from > the 6 o'clock position to the 11 o'clock position. Any suggestions on what > process/processes the vendor should look to for troubleshooting? > > Thanks, > David Smith > Benchmark Electronics > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with following text in > the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information. > If you need assistance - contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ############################################################## > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################