Hello, everyone I am setting up a spray etching bath using merely CuCl2.2H2O and HCl. My questions are 1. What are the concentrations for CuCl2.2H2O (???g/l or ???lb/gallon) and HCl (???ml/l or ???gallon/gallon)? 2. What's the reading of redox potential of a fresh bath at room temperature or at working temperature? 3. How fast is the etching rate using this kind of bath? Any input will be highly appreciated suixin zhang ELIS-TFCG/IMEC, University of Ghent Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium tel: 0032-9-2643371 fax: 0032-9-2643594 Email: [log in to unmask]