Rough Copper for Noise Reduction in High Speed Circuits
A method includes providing, on a printed circuit board, a first copper layer having a first surface roughness, forming, by the first copper layer a power trace to a circuit device, providing, on the printed circuit board, a second copper layer having a second surface roughness, wherein the first surface roughness is greater than the second surface roughness, and forming, by the second copper layer, a signal trace to the circuit device.
1 . A method comprising:
providing, on a printed circuit board, a first copper layer having a first surface roughness;
forming, by the first copper layer a power trace to a circuit device;
providing, on the printed circuit board, a second copper layer having a second surface roughness, wherein the first surface roughness is greater than the second surface roughness; and
forming, by the second copper layer, a signal trace to the circuit device.
2 . The method of claim 1 , wherein in providing the first copper layer the method further comprises:
providing, on the printed circuit board, the first copper layer having a third surface roughness, wherein the first surface rough is greater than the third surface roughness; and
roughening the first copper layer to the first surface roughness.
3 . The method of claim 2 , wherein roughening the first copper layer comprises a mechanical roughening process.
4 . The method of claim 2 , wherein roughening the first copper layer comprises an etching process.
5 . The method of claim 1 , wherein the first surface roughness has a root mean square roughness (R q ) value between 3.5 and 25 micrometers (μm).
6 . The method of claim 5 , wherein the second surface roughness has a R q value between 0.4 and 1.5 micrometers (μm).
7 . The method of claim 1 , wherein the first copper layer and the second copper layer each comprise one of a rolled copper foil, an electrodeposited copper foil, and a resistive copper foil.
8 . The method of claim 1 , wherein the first copper layer operates dampen a high frequency signal component in the power provided to the circuit device.
9 . The method of claim 8 , wherein the high frequency signal component is received via cross-talk from the signal trace.
10 . A printed circuit board, comprising:
a circuit device; and
a copper-clad laminate core, comprising:
a first copper layer having a first surface roughness including a power trace operable to provide power to the circuit device; and
a second copper layer having a second surface roughness including a signal trace operable go conduct a signal of the circuit device,
wherein the first surface roughness is greater than the second surface roughness.
11 . The printed circuit board of claim 10 , wherein the first surface roughness has a root mean square roughness (R q ) value between 3.5 and 25 micrometers (μm).
12 . The printed circuit board of claim 11 , wherein the second surface roughness has a R q value between 0.4 and 1.5 micrometers (μm).
13 . The printed circuit board of claim 10 , wherein the first copper layer and the second copper layer each comprise one of a rolled copper foil, an electrodeposited copper foil, and a resistive copper foil.
14 . The printed circuit board of claim 10 , wherein the first copper layer operates dampen a high frequency signal component in the power provided to the circuit device.
15 . The printed circuit board of claim 14 , wherein the high frequency signal component is received via cross-talk from the signal trace.
16 . A laminate core of a printed circuit board, comprising:
a first copper layer having a first surface roughness including a power trace operable to provide power to a circuit device; and
a second copper layer having a second surface roughness including a signal trace operable go conduct a signal of the circuit device, wherein the first surface roughness is greater than the second surface roughness.
17 . The laminate core of claim 16 , wherein the first surface roughness has a root mean square roughness (R q ) value between 3.5 and 25 micrometers (μm).
18 . The laminate core of claim 17 , wherein the second surface roughness has a R q value between 0.4 and 1.5 micrometers (μm).
19 . The laminate core of claim 16 , wherein the first copper layer and the second copper layer each comprise one of a rolled copper foil, an electrodeposited copper foil, and a resistive copper foil.
20 . The laminate core of claim 16 , wherein the first copper layer operates dampen a high frequency signal component in the power provided to the circuit device.