Hi Anne, In 1 oz copper, you can carry 25 amps on an external layer, with a 50 degrees C rise in conductor temperature above ambient, with a trace .400" wide. In 2 oz copper, you can carry 25 amps on an external layer, with a 30 degrees C rise in temperature above ambient, with a trace about .250" wide. See IPC-2221, Sec 6.2. (or ANSI/IPC-D-275, Sec 3.5.2). Just between us, I'd strongly suggest using a power plane or split power plane to minimize impedance and temperature rise. Michael Hiteshew Lockheed Martin Launching Systems [log in to unmask] (410) 682-1259 > Good Afternoon Technet, > > Does anyone know how thick a trace is required to carry 25 amps in 1 oz > copper? How about 2 oz copper? Let's assume it's .062 thick material. > Need help ASAP. Thanks in advance. > > Anne Ledger > EMDS, Inc. > [log in to unmask] > > ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################