This is a hot topic in the last IPC-Expo and many recent interconnect/packaging conferences. BUM in Japan and SBU(for sequential build-up) in US are all microvia technologies which can be accomplished by laser, photovia or plasma etch. In US, IBM, Continental-Florida and Merix have commercial SBU processes in production. For more details on this subject, see PC Fab. magazine(March issue). Ivan Ho Ciba Specialty Chemicals 508-779-6060 *************************************************************************** * 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] * ***************************************************************************