In this process step, pads and holes are covered with a surface finish. Hotoprint follows RoHS directives. Our customers can choose from different methods.
Our standard surface refinement is Hot Air Leveling (HAL), leaded or lead-free, immersion gold (ENIG) and electroless immersion tin. With the exemption of HAL leaded, these refinements are RoHS-compliant. On request we offer other surface refinements as well.
At HAL, the PCB is pre-treated and dipped into a bath so that all exposed surfaces are covered by solder. Thereafter, excess solder is removed by passing the board between hot air knives.
On the surfaces, which should be refined, the solder remains. Hotoprint has assembly lines for lead-free and leaded processes. In the lead-free process, we use the solder SN100CL from the company BALVER.