Assuming a square trace, the resistance would be Resistance, R = pL/A where p = resistivity of copper = 6.787x10-4 ohms*mil (at 20 deg C) L = length of trace (in mils) A = cross sectional area (in mils) If you want to assume the trace is trapezoidal in shape, then the cross sectional area is A = [(w-h)*h] + (h*h)/2 where w = the plotted trace width h = height of trace Regards, John -----Original Message----- From: Kaye Knotts [mailto:[log in to unmask]] Sent: Tuesday, April 10, 2001 9:59 AM To: [log in to unmask] Subject: [TN] PCB Trace Resistance Chart A few years ago I used a chart that showed the resistance of a pcb trace of a specific length and cross-sectional area. Now I cannot find this chart. Does anybody know where I can find this chart again or know of a way I can calculate the resistance of a particular trace on a board? Thanks, Kaye ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- -----