Stencil Printing
Stencil printing is a method to apply solder paste to the pads of a printed circuit board. After having the stencil aligned exactly to the printed circuit board, the stencil will be lowered onto the board. The solder paste is being pulled across the stencil, paste is being pushed into the apertures and any excess solder over the apertures is being wiped off with the sharp edge of the squeegee. Then the stencil will lift off from the board, releasing the solder paste from the apertures and remain on the pad as a solder depot.