Wave soldering is a large-scale soldering
process by which electronic components are soldered
to a printed circuit board (PCB) to form an
electronic assembly. The name is derived from the
fact that the process uses a tank to hold a quantity
of molten solder; the components are inserted into
or placed on the PCB and the loaded PCB is passed
across a pumped wave or cascade of solder. The
solder wets to the exposed metallic areas of the
board (those not protected with solder mask),
creating a reliable mechanical and electrical
connection. The process is much faster and can
create a higher quality product than manual
soldering of components.
Wave soldering is used for both through-hole printed circuit assemblies, and surface mount. In the latter case, the components are glued onto the printed circuit board surface before being run through the molten solder wave.
As through-hole components have been largely replaced by surface mount components, wave soldering has been supplanted by reflow soldering methods in many large-scale electronics applications. However, there is still significant wave soldering where SMT is not suitable (e.g. large power devices and high pin count connectors), or where simple through-hole technology prevails (certain major appliances).