I'd recommend you fill them with solder if you can. Coating can be used, but its best if you do this AFTER a protective coating is applied to the board like Hot Air Solder Level (hasl) or on a patern plated board (SnPb plated) from which you DO NOT strip the Sn Pb . See my other append about solutions getting trapped in the vias. If at all Possible DO NOT Plug/Tent/Fill vias with anything other than a solder like material that fills them 100% of their depth. hope that helps Jim Herard IBM Microelectronics Quality Engineering [log in to unmask] ---------------------- Forwarded by Jim Herard/Endicott/IBM on 06-11-97 08:39 AM --------------------------- suixin @ elis.rug.ac.be 06-10-97 03:59 PM Please respond to [log in to unmask] @ internet To: TechNet @ ipc.org @ internet cc: Subject: via plugging Hello, everybody I want to get some information on via plugging technology. In my work, the plated through vias are 1.6mm deep and 300 micron in diameter. I have to plug them before further processing. Any input will be greatly appreciated. Thanks in advance. suixin zhang ELIS-TFCG/IMEC, University of Ghent Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium tel: 0032-9-2643371 fax: 0032-9-2643594 Email: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************