Techniques for mass production of large-sized GEM foil by the Korean CMS group for CMS phase-2 upgrade

This study presents techniques for the mass production of large-sized GEM foils for the CMS phase-2 upgrade in Korea. The foil production facility is designed with a focus on mass production, including the adoption of the double-mask technique. A polyimide wet etching technology that uses mono ethanolamine is reported, providing a safer working environment due to its lower inhalation toxicity compared to ethylene diamine. The study also covers the denaturation of the etchant over time and the process of retuning. Finally, R\&D results on soldering surface mount resistors with hot air for faster production are discussed.