We have found that it is possible to gain insight on peeling trace failure modes by microsectioning peeling traces. We are examining our microsections up to about 1000X magnification (according to our objective and eye pieces). At that power you can easily see a electroless copper deposition layer but cannot visualize a direct metalization layer. Separation above, through, or below the electroless copper will give good insight on where in the process to focus your investigation. On occasion we will be able to see a contaminate that is causing separation (particularly ash at the bottom of laser ablated microvias) but usually we can only determine at which level of copper the separation occurs. I have used a solution of Sulfonated Potash (which is toxic) to oxidize bare and imaged panels. The potash oxidizes exposed copper turning it dark blue or black. Areas with a contaminate like resist residue, that is otherwise invisible, will resist the oxidation and remain pink. Resist residues and other surface contaminates can be visualized in this way. You might be able to do the same thing with other, safer chemistries, that mildly oxidize exposed copper without attacking the surface contaminate. Paul Reid PWB Interconnect Solutions -----Original Message----- From: Franklin D Asbell [mailto:[log in to unmask]] Sent: Thursday, April 21, 2005 9:35 AM To: [log in to unmask] Subject: Re: [TN] Peeling Copper traces I would think his comment "pulling away from the foil" would rule out the need for peel strength test. I've never seen conditions that have caused plated copper peeling show up in microsection, of course I've never viewed them over 200X...and it's been my experience angstroms thick passivation contaminates are not viewable in most in-house labs. Where I would begin is water break on the foil panels before and after electroless copper, perhaps experiments involving cleaning and microetch to determine where (on raw foil surface, or during/post electroless copper) the condition is occuring. Franklin ----- Original Message ----- From: "Jeffrey Bush" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, April 21, 2005 7:51 AM Subject: Re: [TN] Peeling Copper traces If the failure is plating to foil you will need to do a microsection to identify the failure mechanism - foil to dep, dep to plate, etc. If the failure is foil to base material you will need to assess that raw material lot for peel-strength. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Rich Olsen [mailto:[log in to unmask]] Sent: Wednesday, April 20, 2005 4:51 PM To: [log in to unmask] Subject: [TN] Peeling Copper traces Hello, What are some likely causes of peeling copper traces? It is plated copper pulling away from the foil copper? thanks, Rich --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------