Brad, I don't know anyone that truly 'loves' the filling and capping process, but I know plenty of folks that adore the additional freedom that the Type VII via structure (see IPC-4761) provides for their complex circuit designs. Admittedly, there was a time not too many years ago when CB-100 was 'the only game in town'. That being said, few will disagree that it is a bear to process. If a given application doesn't require CB-100's conductivity, there are non-conductive fill materials available today that exhibit a lower CTE, higher Tg, and excellent Cu peel strength that are also relatively easy to deposit and planarize in comparison to CB-100. Stephen -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Brad Saunders Sent: Thursday, September 07, 2006 11:18 AM To: [log in to unmask] Subject: Re: [TN] CB-100 Stephen, I love PTH filling and copper capping. What did we ever do before There are a good many materials to choose and not all are correct for all configurations. The silver filled fillers when plannerized have an outstanding copper peel strength. Both metal fillers and non metal fillers need caution inside the PTH they are filling due to all of the CTE energies essentially being transferred to Z axis, hence Tg is important. I would add that voiding needs to be decreased or eliminated as under elevated and or prolonged temps can be a source of root cause failure. Comes down to ensuring that right fill material is used and a controlled process is evoked. Lastly be certain aspect ratio of PTH before filling is properly sized for fill material selected. Brad ----- Original Message ----- From: Stephen Pierce<mailto:[log in to unmask]> To: [log in to unmask]<mailto:[log in to unmask]> Sent: Monday, August 14, 2006 2:57 PM Subject: Re: [TN] CB-100 Ralph, Without addressing CB-100 in particular, here are three important factors to consider when choosing a fill material for lead-free applications: 1) Z-axis CTE 2) Cu peel strength 3) Tg Ideally, you want to minimize the CTE mismatch between the laminate and the fill material. Peel strength becomes key in order to prevent separation between the Cu and epoxy resin if you will be plating directly to the surface of the filled via. Generally speaking, a higher Tg is better. Stephen -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ralph Richart Sent: Saturday, August 12, 2006 7:03 AM To: [log in to unmask]<mailto:[log in to unmask]> Subject: [TN] CB-100 Does anybody have any background on silver filled vias and its suitability for Lead Free Assembly? There are warnings in the literature about heat excursions, and it seems that lead free assembly would make this worse. I found only one email in the archives about delamination associated with filled vias, but never found any answers as to wether the filled vias were the cause, and/or what to do about it. Any insights are appreciated. thanks Ralph --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask]<mailto:[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]<mailto:[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]<mailto:[log in to unmask]>: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives<http://listserv.ipc.org/archives> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16<http://www.ipc.org/contentp age.asp?Pageid=4.3.16> for additional information, or contact Keach Sasamori at [log in to unmask]<mailto:[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 -----------------------------------------------------