pcb circuit trace width
this calculator uses the formula from ipc-2221 (formerly ipc-d-275) to calculate the trace width of a printed circuit board conductor for a given current.
pcb width tool
q: very cool pcb width tool! but i want to know its limitations. i entered a 65 amp current requirement but the track width it returned was definitely incorrect.
answer: the original charts (published in ipc-2221) on which this tool is based only cover up to 35 amps, trace width up to 0.4 inches, temperature rise of 10 to 100 degrees celsius, and 0.5 to 3 ounces of copper. per square foot. when values fall outside these ranges, the formulas used here simply extrapolate.
question: i used your pcb trace width calculator. intuitively i would say the required internal trace width will be less than the external case since the external traces may fall off; according to the calculator the opposite is true? ? ? why?
answer: in air, the outer layer has better heat transfer due to convection. good insulators cover the inner layers so they will get hotter for a given width and current flow. since the trace width calculator attempts to control the temperature rise of the traces, it will make the internal traces wider. in a vacuum or in a potting assembly, you should use the inner layer guide even for the outer layer.
question:temperature risewhat does it mean and how does it apply?
answer:temperature risethis means that traces with current flowing will become hotter than without current. you must determine the degree of temperature rise the board can withstand based on the operating environment and the type of pwb material used. ten degrees is a very safe number for almost any application. if you're okay with the trace width required for a 10-degree rise, you're good to go. if you want to try to remove marks, please ask for a temperature of 20 degrees or higher.
question: when connecting to the ground plane, i use "carriage wheels" or "spokes" to make soldering easier. the trace width calculator told me to make the "spokes" too wide, which defeats the purpose. what do i do?
answer: the spokes of a carriage wheel are very short length traces and the heat sinks to the flat surfaces. the trace width calculator uses empirical formulas based on long traces and no special thermal dissipation. generally speaking, carriage wheel spokes don't have to be as wide as long traces. however, currently i don't know of any good way to count wheel spokes.
answer: the original charts (published in ipc-2221) on which this tool is based only cover up to 35 amps, trace width up to 0.4 inches, temperature rise of 10 to 100 degrees celsius, and 0.5 to 3 ounces of copper. per square foot. when values fall outside these ranges, the formulas used here simply extrapolate.
question: i used your pcb trace width calculator. intuitively i would say the required internal trace width will be less than the external case since the external traces may fall off; according to the calculator the opposite is true? ? ? why?
answer: in air, the outer layer has better heat transfer due to convection. good insulators cover the inner layers so they will get hotter for a given width and current flow. since the trace width calculator attempts to control the temperature rise of the traces, it will make the internal traces wider. in a vacuum or in a potting assembly, you should use the inner layer guide even for the outer layer.
question:temperature risewhat does it mean and how does it apply?
answer:temperature risethis means that traces with current flowing will become hotter than without current. you must determine the degree of temperature rise the board can withstand based on the operating environment and the type of pwb material used. ten degrees is a very safe number for almost any application. if you're okay with the trace width required for a 10-degree rise, you're good to go. if you want to try to remove marks, please ask for a temperature of 20 degrees or higher.
question: when connecting to the ground plane, i use "carriage wheels" or "spokes" to make soldering easier. the trace width calculator told me to make the "spokes" too wide, which defeats the purpose. what do i do?
answer: the spokes of a carriage wheel are very short length traces and the heat sinks to the flat surfaces. the trace width calculator uses empirical formulas based on long traces and no special thermal dissipation. generally speaking, carriage wheel spokes don't have to be as wide as long traces. however, currently i don't know of any good way to count wheel spokes.
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