PCB Copper Trace Thickness & Resistance Calculator
Purpose:
The tool calculates the resistance of a PCB trace depending on its temperature, length, width, thickness or copper weight. Alternatively to the trace dimensions the number of consecutive squares can be used. Dimensions can be entered in the metric or imperial system, temperatures in ºC or ºF. The copper weight is given in oz/ft2 and is directly related to the most popular copper thicknesses on PCBs given in mils or μm.
Input Fields:
Trace Temperature T in ºC or ºF,
Trace Width w in mm, mil, cm or inch,
Trace Length l in mm, mil, cm or inch,
Number n of consecutive squares.
Use of the tool:
The units of the input fields can be changed and the entered values can be converted from one unit into another by use of the list boxes assigned to the input fields. The tool uses a temperature coefficient of 0.0039 K-1 and a value of 1.7 x 10-8 Ωm for the electrical resistivity of copper @ 20 ºC (68 ºF). The trace temperature should be within the range of -100 … +200 ºC or -148 … 392 ºF respectively.
The results for the trace resistance R are shown in the table for the most popular values of the copper weight and copper thicknesses in oz/ft2, mils or μm.
Calculated results might differ from real values depending on the tolerances during PCB manufacturing.
References:
Juergen Schneider; How to use TI's Set of Power Rulers; Texas Instruments Application Report (SLVA278) – September 2007