{"L1_core": {"type": "copper_weight", "domain": "specification", "category": "pcb"}, "L3_technical": {"copper_oz": 3, "standards": ["IPC-4101", "IPC-2221", "IPC-4103"], "thickness_mils": 4.2, "thickness_microns": 105, "thermal_performance": "excellent", "current_capacity_1mm": "4.5A"}, "L2_specification": {"type": "copper_weight", "unit": "oz_per_sqft", "value": 3, "applications": ["high_power_led", "cob", "mcpcb"], "thickness_um": 105}}