Selective soldering with stroke-dip process

Wired components still need to be soldered into SMD-equipped PCBs. Lift/dip soldering is particularly suitable if the solder joints are distributed across the PCB. This process only requires a free space of 1.5 mm around the soldering area and is derived from dip soldering, in which the soldering area is restricted by reducing the solder bath to small soldering nozzles. While the entire PCB is soldered in conventional wave and dip soldering, only defined areas should come into contact with solder in selective soldering. Nozzles with a minimum diameter of 5 mm are possible and the process can be used flexibly for a wide variety of solder joints thanks to quick-change nozzle sets.

During lift/dip soldering, the workpiece is lowered onto the solder nozzles, on which a solder deposit with a convex surface (drop shape) is located. To ensure a constant solder deposit, the principle of communicating tubes is used in the nozzle design. This means that the size and shape of the solder deposit is completely independent of the solder level of the solder bath. The immersion depth has a major influence on the soldering quality. This must be kept constant and requires stable and precise machine mechanics.

Selective soldering systems can be set up as fully automatic machines in "in-line design" or as manual workstations. The basis is the Wolf standard cell.
We provide support in process development and offer the possibility of soldering tests and pre-series production in our technology center.