Rudy, You are correct the boards do not have buried vias, but the delamination does not necessarily locate adjacent to a hole. Tests on bare boards showed that they do occur primarily at one end of the PWB on layer 5 of 8. The delaminations occur on the "sawtooth" side of the copper. Additionally, examination through the laminate on the secondary side (layer 8) revealed black patchy areas over large land patterns or ground planes on layer 7. These also occur on the sawtooth side of the copper. Although these areas have not delaminated, I have confirmed that the laminate resin does not bond to these areas and EDS showed the same presence of sulfur and tin that was observed on the delaminated surfaces. Do you know what chemical preparation the sawtooth side of the copper is exposed to in order to improve adhesion? Thanks Rudy for your time. Best Regards, Jeff -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: Wednesday, February 13, 2002 3:33 PM To: [log in to unmask] Subject: [TN] Delamination In a message dated 2/13/02 2:58:07 PM Pacific Standard Time, [log in to unmask] writes: << I am looking for some information regarding the preparation of copper foil for adhesion to internal laminate layers in the construction of PWBs. I am presently experiencing delamination of the copper from the laminate prepreg on an internal layer after IR reflow exposure. EDS of the delaminated surfaces showed localized, high-concentration of sulfur and tin on the copper surface >> Jeff: I assume that this delamination is occuring adjacent to drilled holes? These are not buried via boards are they? Rudy Sedlak RD Chemical Company ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- The information contained in this email message may be privileged and is confidential information intended only for the use of the recipient, or any employee or agent responsible to deliver it to the intended recipient. Any unauthorized use, distribution or copying of this information is strictly prohibited and may be unlawful. If you have received this communication in error, please notify the sender immediately and destroy the original message and all attachments from your electronic files. --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------