Abstract: A solderable layer has an organic buffer film (OBF) and an immersion tin coating deposited on a substrate. The OBF is first coated on the surface of the substrate to modify the surface of the substrate and having fluorocarbon-based polymers (solution type). The immersion plating solution pass through the OBF and the immersion tin coating is then coated on the substrate. A method to manufacture the solderable layer according to any one of claims 1 to 12 has following steps of (1) coating an organic buffer film (OBF) on a surface of a substrate to form a modified surface, (2) drying the modified surface, (3) applying the substrate into a solution with immersed tin compositions to allow the immersed tin to deposit on the modified surface, (4) rinsing the modified surface with water and (5) drying the substrate.