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 by the Korean CMS group. 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.