Solder Surfaces for Printed Circuit Boards, Part 4: HAL lead-free
The HAL lead-free solder surface offers the best solderability of all surfaces, but the thickness of the tin layer varies.
The HAL lead-free solder surface offers the best solderability of all surfaces, but the thickness of the tin layer varies.
For the Soldering surface immersion tin (chem. Sn) or ISn (immersion Tin), a 1 to 1.3 µm thin tin layer is deposited on the copper surfaces in a wet chemical process. According to IPC-4554, this is ≥ 0.6 µm pure tin (usable tin). The tin layer forms a planar soldering surface and thus provides the
The solder surface electroless nickel-gold (chem. NiAu) is also called ENIG (Electroless Nickel Immersion Gold). In a wet chemical process, a 3 to 6 µm thin layer of nickel (phosphorus-doped) is first deposited on the copper surfaces of the component connections. The nickel layer forms a barrier for the 0.05 to 0.125 µm thin gold
The solder surface, final surface or also called PCB finish, is a thin metallic or organic layer that the PCB manufacturer applies to the copper surfaces of the component connections (solder pads). The solder surface covers the exposed copper on the PCB and preserves the solderability within the guaranteed storage period of the PCBs under