One of the reasons people started to tent/plug vias was that it is impossible to guarantee 100% filling the ALL the vias with solder. Partially solder-filled holes have shorter fatigue lives than either non-solder-filled holes or 100% solder-filled holes. However, for most applications this reduced fatigue life is of no consequence because even the reduced fatigue life is much longer than the product life. Only for severe thermal cyclic use conditions (deltaT's>~60C) and also depending on the via construction and quality, is this reduced fatigue life significant. Werner Engelmaier Engelmaier Associates, Inc. Electronic Packaging, Interconnection and Reliability Consulting 23 Gunther Street Mendham, NJ 07945 USA Phone & Fax: 973-543-2747 E-mail: [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] * ***************************************************************************