Analysis of silver ion and complexing agent in tin-silver electrodeposition solution

摘要

The present disclosure relates to methods of monitoring the concentrations of silver ion and complexing agent in tin-silver (SnAg) electrodeposition solutions, and analysis and process control using such methods. Methods can include adding a precipitating agent to an electrodeposition solution including at least tin ions, silver ions, and complexing agent to cause a reaction between at least a portion of the precipitating agent and substantially all of the silver ions (to precipitate silver ions as a precipitant); adding a metallic salt to the electrodeposition solution to cause a reaction with substantially all of the remaining precipitating agent; measuring the endpoint of the silver ion back titration; further adding metallic salt to cause a further reaction with the complexing agent; and measuring the endpoint of the complexing agent titration.