Don't have the study info or data, so I guess this posting is useless unless you consider: Did this thing in the early 1970's when I was an up and coming process engineer. The customer was HP and they required no lands and 1.5 mils of copper in the holes (thereby providing lands), minimum, plated with electrolytic gold. I was at Xerox Pomona (87,000 square foot PCB fab shop) and we built hundreds of thousands of this MLB type with no hole failures in up to 8 layer boards. Gold was under $32/oz. Tom Miller and the gang set out to ruin most of us for even wanting to do the boards they did in house (vertically integrated in those days - how time changes everything). Your desire to save real estate is a good one. Just make sure the copper thickness is there and the ductility is high. MoonMan --------------------------------------------------------------------------------- Technet 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 Technet To temporarily halt delivery of Technet send the following message: SET Technet 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 ---------------------------------------------------------------------------------