Cleaning of stencils and misprinted PCBs has taken an increasingly important role in surface mount technology. Fine and ultra-fine pitch lands, together with other advanced packages, place new demands on stencil cleaning. Paste volume is a critical issue for fine, ultra-fine, chip-scale, BGA and flip-chip components. Insufficient solder due to clogging of stencil apertures is a primary cause of defects. The purpose of this handbook is to provide a basic understanding of stencil-misprint cleaning processes. 24 pages. Released February 2007.