Hello ! In IPC specification ANSI/IPC-RB-276, 1992, for "Qualification and Performance Specification for Rigid Printed Boards" it is specified a copper thickness of 15µm for buried and blind vias with a min.thickness of 13µm. However this spec. was changed during 1996, IPC-6012, there the copper thickness for blind vias were increased to an average thickness of 25µm with a min. thickness of 20µm. Does anyone know why they changed their specifications? Is there someone who has any experience of blind and buried vias with thin copper coatings (15-13µm)? Thanks in advance for your help //Markus Markus Gauffin M.Sc. Printed Board Assembly Technology tel: +46 8 719 16 34 fax: +46 8 719 71 99 e-post: [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] * ***************************************************************************