Hi, I have a little physics problem maybe someone can help me with. I'm looking for an equation to solve for the temperature rise in a trace with a given amperage over a given period of time. Here's the problem: A copper (inner layer) trace will have 6 amps on it (under short circuit conditions) for a maximum of 128 microseconds. For a given trace width and length, I can calculate the DC resistance. What I can't calculate is the temperature rise on that trace over that time. Obviously, I need to know this to ensure I don't approach the fusing temperature of the copper. I'll turn this into a science project if I have to, but I'm wondering if anyone has this equation at their fingertips. Thanks in advance if you do. Michael Hiteshew Lockheed Martin Launching Systems [log in to unmask] (410) 682-1259 ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################