Detailed Product Description PCB of Single-Layer Board and Single sided pcbs,we specialize in Single board and Double board.Laminate materials: ... FR-4, FR-1 and CME-1With immersion gold-plated finish and wide applicationsNumber of layers: single-layer, double-layer, ... OSP, HAL, immersion AU, silver, soft Au, nel plating and gold fingerTwist: 0.5%Insulation resistance: 10 (11)MΩ ...