Through-mold electrodeposition using the uniform injection cell (UIC): Workpiece and pattern scale uniformity

We report on the operation of an electroplating device based on the uniform injection cell (UIC) concept. Workpiece scale mass transfer characteristic s are explored using limiting current measurements and are related to theor etical predictions. Results show that the device delivers predictable and c ontrolled average mass transfer rates at the workpiece length scale. Patter n scale uniformity is explored by electrodeposition of NiFe microgears on t o a patterned substrate. Statistical analysis of compositional differences between an electroplated NiFe film and electrodeposited NiFe microgears is used to explore mass transfer on the pattern scale, Results illustrate that the presence of a patterned mold influences the average mass transfer rate compared to the unpatterned electrode, but does not create additional vari ability in electrolyte mixing across the substrate, Implications for using the device in through-mold plating are discussed and future improvements to the device are suggested. (C) 1999 Elsevier Science Ltd, All rights reserv ed.