E-Powertrain Assembly line high-voltage inverter


Sonplas has developed a flexible production line for the assembly and testing of HV inverters. The standardized assembly and testing modules (individual machines) are characterized by a small footprint while at the same time being easily accessible from the front and rear side which e.g., facilitates maintenance activities. Subsequent cycle scaling (120s to 40s) is possible at any time. The machines are connected via a modular workpiece carrier system. It is loaded and unloaded at ergonomically optimized workstations. The assembly and testing processes are fully automated. The specifications for this are provided by the database-based, flexible test plan system from Sonplas. The individual assembly and test steps can thus be configurated in any sequence and number, as well as with different parameter specifications, to form a sequence plan. Furthermore, connection to the customer’s higher-level MES is possible at any time. A specific highlight is the built-in automatic welding station with a green laser (copper welding). For this purpose, the laser scanner optics are positioned at different points with a 6-axis robot in order to be able to weld both vertically and horizontally with only one optic. Fine positioning is camera-based using the component edges. The line offers integrated product identification by means of DMC or barcode as well as continuous tracking of the components on the workpiece carriers within the line. This ensures continuous part traceability. In addition, an ECO mode is implemented for the entire line, thus saving energy. Due to the workpiece carrier system, the assembly system can be modified for other inverter types without much effort.



  • Standardized assembly and test modules
  • Cross-line ECO mode for energy saving
  • Automatic PCB pressing, so-called press-fit pin
  • Robot-based copper welding with a green laser
  • Database-based, flexible test plan system
  • Modular workpiece carrier system (semi-autonomous)
  • Integrated process time monitoring
  • Assembly and EOL testing from a single source


  • Laser cleaning
  • Cleaning with ionized air (Taifun cleaning)
  • Dispensing (1K and 2K)
  • Pin check
  • Assembly processes (e.g., screwing, pressing)
  • Laser welding
  • Labelling
  • Flashing
  • EOL tests (High-voltage and function tests)