Throwing Power measurement: The assaf Cell

A new throwing power cell is described in detail; it has the virtue of being usable as a small fixture that can be positioned in an electroplating tank. This so-called Assaf Cell is particularly useful for simulating small recesses, typically through-holes found in printed circuit boards (PCBs). This paper demonstrates how a Throwing Power Index, given by the ratio of metal thickness on the front and rear faces of the Assaf-Cell test panel, may be used to evaluate/optimize electrodeposition conditions. Data are presented from work using various electrolytes, including high-throw acid copper solutions, thereby illustrating its usefulness and application.