ABSTRACT
The printing of solder paste onto a printed circuit board at an acceptable quality standard is essential to successful reflow soldering of surface mounted components. Stencil printing is currently the most popular technique for depositing solder paste. The stencil defines where and how much solder paste is deposited onto the PCB pad. Stencil masks are made of solid metal foil traditionally chemically etched to provide a defined pattern of cavity openings corresponding to the component lead pads. Problems that may occur with the
printed deposit include skipping; paste is not fully transferred through the stencil and also bridging; neighbouring deposits coalesce.
