A mixed reality (MR)-based concept for supporting and optimizing the way operators work with automatic printed circuit board (PCB) assembly lines, is proposed. In order to enhance the work process’ interface, users are outfitted with a head-mounted display (HMD), so they can both actively access process relevant machine data and passively receive system notifications in a heads-up display (HUD), instead of having to manually query the terminal of the machine of interest at its very location. This approach was implemented and tested in a field study with one of the assembly lines of an electronics manufacturing services (EMS)-company. 30 staff members were recruited as test subjects and 90% of them appreciated the system deployment, due to its noticeable additional benefits compared to the status quo.