Hello all, Apologies if you get this message twice, I didn't get the usual the usual 'your message has been sent' message so I assume it has disappeared into the ether! Anyway here goes: I have a question for all you board manufacturers (and PCB designers) out there. I have been working on an unusual 4-layer board which has 2oz copper on all layers. The majority of the tracking is on the inner layers, and the outer layers are effectively solid planes of copper. Many of the tracks on the inner layers have to carry a lot of current, but there is also some control circuitry which requires a clearance of 6.5mm from the high power area. Here lies my problem. Due to the space limitations and clearance required, I have tracked in a connector using 8th tracks which travel almost the length of the board (around 110mm) along one edge. These 3 tracks are on their own, 6.5 mm from the rest of the tracking, adjacent to each other with 8th gaps. My question is - is this achievable? how much of a problem would this cause the manufacture? The inner layers MUST be 2oz copper. My second question is - If 2oz of copper was specified for all layers, is it acceptable to plate up the inner layers from 1oz copper foil? A manufacture told me they had done this (although in fact they had not!) but I have never heard of this practice for inner layers before. This is a hot issue for me a the moment and I would appreciate any advice or comments. Best Regards, Mark Holmes [log in to unmask] Mark Holmes PCB Designer Helvar Merca Ltd. Hawley Mill, Hawley Road, Dartford Kent. DA2 7SY Tel: 01322 22 22 11 Fax: 01322 282 286 mailto:[log in to unmask] http://www.helvar.com ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################