The most important part of the surface mount assembly process (SMT) is the application of solder paste to the printed circuit board (PCB).
One of the most common methods of applying solder paste to a PCB using a stencil printer is squeegee blade printing. The squeegees are used to apply the necessary force required to move the solder paste across the stencil and on to the PCB pads. Squeegees are usually made from metal, but can also be made from polyurethane.
The aim of the process is to accurately deposit the correct volume onto each of the pads by screen-printing the solder paste through a stencil or foil. This part of the process accounts for the majority of assembly defects if not controlled correctly.
