If you want, I can:
If you just need the technical requirements (not the full PDF), here are the critical points from the standard: ipc4556 pdf
In standard PCBs, etching is fairly precise. In heavy copper, etching "shadows" becomes a major issue. The standard defines minimum spacing requirements relative to copper thickness. As a rule of thumb found in the standard: as the copper gets thicker, the minimum spacing must increase to prevent shorts during etching. If you want, I can: If you just