... . 5.Drop Shippin 0.High quality aluminum pcb board. 0.we have UL certification ! 0.Paking is ... pcb,FR4Layer counts Single, double, four layer, and 6-30 layer boards are available Surface finish /Treatment HASL ... blind/buried vias, characteristic impedance control, Rigid-flex board etc Special requirement Buried/blind vias +controlled impedance + ... real factory,welcome to our factory! led circuit board