Printed Circuit Board of 4 layers Special thickness of 1.0 mm Special holes size of 0.015mm Red solder mask 4 layers PCB ... of 0.015mm4. Impendance ControlOur PCB capacity as below:Base material: FR4, FR1, FR2, Ceramics, Aluminum, Rogers, F4B, F4BK, F4BT ... x 620mm (18 x 24) Board finishing type: Hot air leveling, soft gold, hard gold, immersion gold, gold fingers. 4 layers Printed Circuit Board