Analysis of the Stability of the Chemical Composition of Wastewater in the Production of Printed Circuit Boards

Abstract

A method for analyzing the stability of the chemical composition of wastewater in the manufacture of printed circuit boards using statistical methods of process control is proposed. The correlation and normal distribution of the monitored indicators is evaluated. Types of control charts are selected that provide control of both the average level of the process and its dispersion. To control the stability of independent indicators, Shewhart charts are used. Monitoring of correlated indicators is carried out using the Hotelling control chart. If it is necessary to control the multidimensional dispersion of the process, generalized variance charts can be used. The proposed approach ensures the detection of process violations before the monitored indicators are out of tolerance.