I believe that glass etching, as a minimum to "frost" or micro etch the glass is needed. Sodium Bifloride and replaced some of the more aggressive chemistries over the years, but anyone doing a good desmear and certainly plasma needs to remove the glass left protruding. It is only on the order of .2 mil, but given the drive to refine the cu plating processes to support the increasing densities, the copper thickness in the barrel will be kept to a minimum. Both desmear and glass etch are critical to maintain a reliable copper barrel. Jeffrey Bush Director, Quality Assurance and Technical Support 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302-1890 Tel. 802.257.4571.21 Fax. 802.257.0011 [log in to unmask] http://www.vtcircuits.com -----Original Message----- From: Reeves, Tim R. [mailto:[log in to unmask]] Sent: Wednesday, March 31, 2004 2:04 PM To: [log in to unmask] Subject: Re: [TN] Hole wall quality Everyone is saying inadequate glass etch but few fabricators these days are really using a glass etch. Drilling doesn't look good, but I'd say it's over-aggressive desmear. That's why so much glass fiber protrusion. Franklin, what was desmear condition? Alkaline permanganate? How long, what temp.? One-pass or two? Is it ordinary FR-4, high Tg, or more high performance material? The plating definitely looks thin, based on comparison with inner foil, whether it's 1 oz. or 1/2 oz. Tim Reeves Tyco Printed Circuit Group - Dallas Division -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Werner Engelmaier Sent: Tuesday, March 30, 2004 9:08 AM Subject: Re: Hole wall quality Hi Franklin, Whether or not these PWBs will give trouble in service depends on the product appllication--o.k. for benign environments, likely to fail in servere environments. The certainly are not the prettiest x-sections I have seen--inadequate glass etch, some glass-fiber rip-out, l plating rather thin---all resulting in stress risers in thin plating that is thinner still localized. Regards, Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Fax: 386-437-8737 E-mail: [log in to unmask], Website: www.engelmaier.com --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------