4layer with heavy copper 3oz used for industry control from china Base material: fr4 Layercount: 4layer Copper thickness: 3/3/3/3oz Board thickness: 2.0+/-0.18mm Minimum hole size: 0.15mm Minimum line width: 3mil Minimum line spacing: 3mil Surface finishing: immersion gold (2u) Solder mask: green Silk screen: white Dimension:255mm*278mm Special: 3oz copper thickness Routing/punching:cnc-test: 100% Inspection standard: ipc-a-600h/ipc-6012b, class 2/3 Outgoing reports: final inspection, e-test, solder ability test, micro section and so on