Could someone please give me a general guideline concerning the additional cost of using blind vias on a PCB? Perhaps there is someone out there in the PCB fabrication business or a fellow designer that has done some extensive research into this? We don't have need for buried vias, yet, but are using more CSP packages (.5 mm pitch with .3 mm pads) that require blind micro via-in-pad in order to get the signals out of the center pads. An added challenge is that we are also required to have 50-ohm controlled impedance micro-strip lines. This makes it rather difficult to use very small micro-vias, due to the restricted aspect ratio of ~ .7:1. TIA, for any information you can provide. Ray Humphrey Senior PCB Designer Maxim Integrated Products --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------