Heavy Copper PCB for High Current Power Applications

In terms of copper weight, SFX PCB manufactures ultra-heavy copper PCBs with copper foil thicknesses up to 20 oz (approximately 700 µm). For overall board thickness, rigid PCBs can be produced up to 8–10 mm depending on the substrate and layer configuration. The appropriate thickness depends on your current load, thermal, and mechanical requirements.

Heavy copper refers to a copper weight exceeding 3 oz per square foot (approximately 105 µm thickness) on a PCB layer. Unlike standard PCBs that use 1 oz copper, heavy copper boards are engineered for high current carrying capacity, superior thermal management (copper's thermal conductivity is 401 W/mK), and enhanced structural integrity at plated-through holes and connector points.

Heavy copper PCBs are widely used in power distribution and power modules, electric vehicles (EVs), aerospace and satellite systems, military radar and weapon control systems, medical equipment, nuclear and solar energy systems, welding tools, UPS systems, and rail traction applications where high current loads and thermal management are critical.

Layer count depends on the copper weight. For 3–4 oz copper, up to 24 layers are achievable in sampling and 20 in mass production. For 5–6 oz copper, up to 20 layers (sample) and 16 (mass production). At 7–12 oz copper, up to 12 layers (sample) and 10 (mass production). Higher copper weights require wider spacing, which impacts maximum achievable layer counts.

Line width and spacing increase with copper weight to ensure manufacturing precision. At 3 oz, spacing starts at 6/6 mil (sample). At 5 oz, it is 8/8 mil; at 6 oz, 10/10 mil; and at 10 oz, 12/18 mil. These specifications ensure reliable etching, current distribution, and electrical isolation across the board for high-power designs.

Yes. Heavy copper layers can be integrated into metal core PCBs (aluminum or copper base), ceramic PCBs, and multi-layer rigid or rigid-flex configurations. For example, copper core MCPCBs support 1–10 oz copper foil with thermal conductivity up to 400 W/mK, while ceramic PCBs support 18–300 µm (up to 8.5 oz) base copper for semiconductor-level thermal management.