Cryo-FIB-preparation and cryo-SEM investigation of gold nanolayers used as absorber for laser welding of polymer foils

The morphology of welded polymer foils was investigated by Scanning Electron Microscopy (SEM) using Focused Ion Beam (FIB) technology for cross-sectional preparation. Due to the sensitive structure of the copolymer Ethylene Tetrafluororethylene (ETFE), FIB preparation and SEM investigation were performed at cryo conditions. A gold nanolayer was used as absorber for the laser beam to weld the transparent copolymer foils. The embedding of the gold nanolayer inside the welding seam and its influence on the mechanical stability of the welding seams was demonstrated.