Mike, It looks like you have exceeded the plugging criteria on two practical counts - 1) is that your aspect ratio is too high (6:1 is deemed to be the limit a hole can be filled to and 2) is that all the fab houses I've talked with who are experienced with the plugging process baulk at filling holes smaller than 12 mils and that's with a 4:1 aspect ratio. I can't say for sure what's happening to your boards, but I would hazzard a serious guess (given the circumstances) that the VIA plug has been unable to outgas properly, and since the epoxy has cured, there is nowhere now for trapped gasses to escape to. If possible, open out your holes to 15 mils and have a serious word with your fab house to see if they truly understand the VIA plugging process. Outgassing the material properly prior to filling, especially for small diameter/high aspect ratio holes, is of prime importance. I've used this process on quite a few boards now, and only has two troublesome episodes - both at start-up with a new fab house, where plating adhesion wasn't as good as it should have been. Hope this matches one of your favourite theories. Peter Michael.Forrester@ LECROY.COM To: [log in to unmask] Sent by: TechNet cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST <[log in to unmask]> Aero/ST Group) Subject: [TN] Dupont CB100 VIA Plug and Delamination 02/01/02 08:28 AM Please respond to "TechNet E-Mail Forum."; Please respond to Michael.Forrester We have been having a problem with Dupont silver CB100 VIA Plug. The boards are 12 layer, .062", FR4, Nickel/Gold plated. We have a BGA pattern with VIA in hole. The VIAs are filled with CB100 VIA plug and then the board is plated. The VIAs are .010 causing an aspect ratio of 6.2:1. We are seeing after solder reflow, inner layer delamination in the area of the VIA filled BGA patterns. Has anyone seen this before? Does anyone use a similar construction and had success? There are a few theories flying around but I wanted to ask the IPC community for any insight. Thank you in advance. Best Regards, Mike Forrester Sr. Manufacturing Engineer [log in to unmask] --------------------------------------------------------------------------------- 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 --------------------------------------------------------------------------------- [This e-mail is confidential and may also be privileged. If you are not the intended recipient, please delete it and notify us immediately; you should not copy or use it for any purpose, nor disclose its contents to any other person. Thank you.] --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------