Appear to be normal epoxy fill of the blind via to the surface copper. The center via shows the epoxy above the surface plane. Poor sealing of the via at lamination coupled with inadequate resin removal post-lamination appears to have created the bumps. The extent of epoxy bumps would have required some mechanical planarization, which is not needed in this design if the correct materials and process are used to dam the resin from flowing topside at lamination. We use Paco-Via which results in a slight dimple as the material conforms the via during lamination. Other materials like copper foil are used which do result in a larger bump that could required planarization. Very good Okie microsection - comparable to any Yankee attempt! 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: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Tuesday, September 13, 2005 5:44 PM To: [log in to unmask] Subject: Re: [TN] raised vias...I did a "Okie" cross-section Hi All! I have a local shop here do a lot of cross-sections for us, but I couldn't take the board over to them until tommorrow. But I was so curious to take a look at the bumps, or "raised vias", I decided to do what I could, to see what I could. We're not set-up to do cross-sections here (that may change in the future), but I took a dremel tool and got close to where I wanted to look, then started using finer and finer grit wheels. Then I used an exacto knife and carefully scraped material away until I was able to see how things looked at the raised vias. This was done under a microscope, and I mean it was done carefully. I know it's not as good looking as what a real cross section would look like, but it does give an idea of how things look. Go to: http://www.stevezeva.homestead.com and look at "Okie Cross-section". I still don't know why I have the bumps...they look like they're solid copper. Kind regards, -Steve Gregory- Senior Process Engineer LaBarge Incorporated Tulsa, Oklahoma (918) 459-2285 (918) 459-2350 FAX __________________________________________________________________ This message may contain information that is privileged and confidential to LaBarge, Inc. It is for use only by the individual or entity named above. If you are not the intended recipient, you may not copy, use or deliver this message to anyone. In such event, you should destroy the message and kindly notify the sender by reply e-mail. --------------------------------------------------- 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 -----------------------------------------------------