The Relationship Between PCB Trace Width And Current

- Dec 08, 2016-

PCB carrying capacity depends on the following factors: line width, line thickness (copper

foil thickness), allowing temperature rise. As we all know, PCB traces wider,greater carrying


PCB copper sheet width and runs through the size of the power flow calculation method

General PCB board copper thickness of 35um, line width of 1mm, then the line of the 

cross-sectional area of 0.035 mm2, usually take the current density of 30A / mm2, so that per

millimeter line width can flow 1A current.

PC275 - A formula for calculating the standard, with temperature rise, the thickness of the

copper foil, A

I = 0.0150(DT 0.5453) (A 0.7349) for IPC—D—275 Internal Traces

I =0.0647(DT 0.4281) (A 0.6732) for IPC—D—275 External Traces

2、The relationship of PCB trace and current 

  Different thickness of different widths of the copper foil current carrying capacity 

as follows:

Copper foil thickness 35um 

Copper sheet thickness of 50 um 

Copper sheet thickness of 50 um  

Note: with copper wire by large current carrying capacity of the width of the copper foil should

refer to the table of numerical derating 50% area choose to consider We are an OEM one-stop

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