A study was performed to develop an accurate, on-line method of determining the cuprous chloride concentration in a typical cupric chloride etcher. A technique was developed using the slope between two spectrophotometric absorption points produced by scanning a solution sample. An on-line monitor was developed to produce a faster and more accurate method of solution concentration control for a typical cupric chloride etching solution. Slope increased linearly with increasing cuprous concentration when the 535 and 560 nanometer bandwidth filter combination was used. Monitor accuracy was found to be independent of cupric concentration, hydrochloric acid concentration, and temperature over the cuprous concentration range of interest which extends from zero to twenty grams per liter.
Library of Congress Subject Headings
Etching reagents; Printed circuits; Electronic apparatus and appliances
Department, Program, or Center
School of Photographic Arts and Sciences (CIAS)
Mee, Christine, "Spectrophotometric studies of individual components of a cupric chloride etchant used in printed wiring board manufacturing processes" (1986). Thesis. Rochester Institute of Technology. Accessed from
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