MEANS FOR DETECTING AND ADJUSTING METAL SALT CONCENTRATION IN AN ELECTROLESS PLATING BATH

摘要

A method and apparatus are described for the continuous monitoring of a solution such as an electroless nickel plating bath, and the routine adjustment of the bath during use. The apparatus comprises a probe adapted to be placed directly into the plating tank, and controller means for replenishing nickel ions and other plating additives as they are depleted from the bath. The probe uses a light source for passing a beam of monochromatic light through a portion of the bath and a detector for measuring the intensity of the light. Means are used to prevent air and hydrogen bubbles in the bath from affecting the reliability of the measurements. Additional means are used for cooling of the electronics and the portion of the bath through which the light is directed.