Impedance factors in PCB processing

1. The thickness of the dielectric layer is proportional to the impedance value. 

2. The dielectric constant is inversely proportional to the impedance value. 

3. The thickness of the copper foil is inversely proportional to the impedance value. 

4. The line width is inversely proportional to the impedance value. 

5. The thickness of the ink is inversely proportional to the impedance value. 

So we should pay attention to the above points when controlling the impedance.