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Conductor / Copper thickness

The following table shows the maximum allowed conductor trace width with the minimum conductor trace spacing, depending on the respective copper thickness.

Outer* and Inner layers

* Copper thickness after electroplating
Copper thickness
Outer* and Inner layers
Standard
Min. conductor trace width | -space | annular ring
Special production
Min. conductor trace width | -space | annular ring
18µm100µm | 100µm | 100µm75µm | 75µm | 75µm
35µm100µm | 100µm | 100µm90µm | 90µm | 100µm
70µm150µm | 150µm | 150µm150µm | 150µm | 130µm
105µm225µm | 225µm | 225µm200µm | 200µm | 170µm
140µm300µm | 300µm | 300µm250µm | 250µm | 200µm
175µm400µm | 400µm | 400µm280µm | 280µm | 240µm
210µm450µm | 450µm | 450µm300µm | 300µm | 280µm
245µm475µm | 475µm | 475µm350µm | 350µm | 320µm
280µm500µm | 500µm | 500µm380µm | 380µm | 350µm
315µm525µm | 525µm | 525µm380µm | 380µm | 350µm
350µm550µm | 550µm | 550µm380µm | 380µm | 350µm
385µm575µm | 575µm | 575µm380µm | 380µm | 350µm
400µm600µm | 600µm | 600µm380µm | 380µm | 350µm
455µm700µm | 700µm | 700µm380µm | 380µm | 350µm
490µm700µm | 700µm | 700µm380µm | 380µm | 350µm
525µm700µm | 700µm | 700µm380µm | 380µm | 350µm
560µm800µm | 800µm | 800µm380µm | 380µm | 350µm

Effect of the copper thickness on the line resistance

In the favourable pool service for 4 layers, either 18µm or 35µm copper is possible on the inner layers. The influence on the line resistance and voltage drop is negligible in most cases.

With standard copper thicknesses, we generally recommend using the largest possible conductor track widths/copper areas on the power and ground layers.

Example of the resistance of a 100mm wide conductor with a length of 100mm on the inner layer

Copper thicknessConductor diameterLine resistanceVoltage drop
18µm1.8 mm²0.0012 Ohm0.0304 V
35µm3.5 mm²0.0006 Ohm0.0230 V