Past and current use of micro vias (blind and buried) with no issues or problems at this point using highly qualified suppliers. I'll show you my pictures With blind vias, plated over, hope you don't mind small dimples on SMT solder termination areas. This technology gets you down to the next layer where the dogbone for under 1 mm pitch BGA's is located, etc. Reliability issues still not resolved for long term but IPC-D-279 should soon as will the joint IPC/JPCA- 2315 design guidelines from a design perspective. Again, it all depends on the supplier process management capabilities. More are coming forward without having done any of what you request so beware. Mostly the technology you want has been done for some time. MoonMan --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------