Fine Lines in High Yield (Part CVⅢ): Novel Fluid Movement and Drying Techniques

摘要

PWB fabricators have relied for decades on conventional fluid movement techniques in wet processing such as spraying, air sparging, knife-edge and paddle agitation. Improved fluid dynamics were then needed to process boards with high aspect ratio through-holes and blind vias. An improved rinsing technique was introduced by IBM in the form of the Fluid Head~(TM) design (see also under "Drying"). Better through-hole and blind via fluid dynamics were achieved by "eductors," fluid "push/pull" devices such as flood bars and vacuum extraction, and ultra-sound assisted designs.