{"L1_core": {"type": "copper_weight", "domain": "specification", "category": "pcb"}, "L3_technical": {"copper_oz": 2, "standards": ["IPC-4101", "IPC-2221", "IPC-6012"], "thickness_mils": 2.8, "thickness_microns": 70, "current_capacity_1mm": "3A"}, "L2_specification": {"type": "copper_weight", "unit": "oz_per_sqft", "value": 2, "applications": ["led_drivers", "power_circuits"], "thickness_um": 70}}