gold finger PCB board: 1.HASL,double sided 2.Shengyi material 3.free sample ... for your reference: Product Categories:single/double sided board, multi-layer board, high density board, including MLB with blind/buried via holesMain base ... , OSPBoard Thickness:Inner core thickness 0.15-1.5mm, finished board thickness 0.20-3mmCopper Foil Thickness:1/3 OZ–5 ...