PCB Blog

What Is The Relationship Between The Track Width In A Pcb And Maximum Current That Can Pass Through It?

for example a PCB track with 1mm tickness can not pass 40A direct current.
Please give me a formula or a table to calculate the track width according to maximum current can pass through it.
many thanks.

One Response to “What Is The Relationship Between The Track Width In A Pcb And Maximum Current That Can Pass Through It?”

1. robert h Says:
   June 24th, 2009 at 4:29 pm

   First look up the resistivity of copper.
   Measure the length of the track needed.
   Now calculate the cross section of the track you propose to use.
   Now work out the resistance of the track over its length.
   Now calculate the voltage drop at the current you propose it needs to carry.
   Now calculate the power dissipation in the track. Now, using metallurgical data, calculate the temperature increase in the track.
   Decide if you are happy at that temperature.
   If not, the power dissipation will decrease by half by doubling the width of the track (provided the current is the same).
   Or you can do it the easy way. Ie, use a wire bridge thick enough to handle the current you require.

Leave a Reply