Bubble and foam solutions using a completely immersed air-free feedback flow control valve

An apparatus for electroplating material onto a substrate, comprising:

• an electroplating cell comprising:
• a vessel for holding electrolyte;
• a weir wall positioned at the periphery of the vessel;
• and
• a fluid collection trough substantially surrounding the weir wall, such that during electroplating, electrolyte flows into the vessel, over the weir wall and into the fluid collection trough;
• an electrolyte reservoir;
• a return conduit for delivering electrolyte from the fluid collection trough to the electrolyte reservoir;
• a plating recirculation loop comprising the electrolyte reservoir, a pump, the electroplating cell and the return conduit;
• an electrolyte meter for sensing a level of fluid in the fluid collection trough;
• a drain valve positioned in the return conduit;
• and
• a drain controller configured to control a position of the drain valve based on the level of fluid in the fluid collection trough received from the electrolyte meter, wherein the drain controller is configured to cause the level of fluid in the fluid collection trough to remain above a target electrolyte level to thereby ensure that no gas enters the return conduit during electroplating.