I'm laying out a 4-layer PCB for a SMPS. Due to component density the layers in a particular area area are as follows:
- Layer 1: High power traces switched at ~100kHz + Components and heavily filtered DC signals
[~0.2mm FR4] - Layer 2: Ground
[~1.2mm FR4] - Layer 3: High power traces switched at ~100kHz
[~0.2mm FR4] - Layer 4: Components and heavily filtered DC signals
I've got a question about the height of a PCB trace above a ground plane.
I've got high power traces switched at 100kHz on layers 1 and 3. While I've got a ground plane on layer 2.
The distance of layer 1 to the ground plane on layer 2 is 0.2mm.
The distance of layer 3 to the ground plane on layer 2 is 1.2mm.
Does this difference in height make for a large difference in radiated EMI? Magnetic / capacitive coupling to nearby traces? etc.
Thanks!