Through a redesign of the already well-known automatic cell measurement for solar modules, MBJ Solutions has now succeeded in integrating the function into its electroluminescence tester without any impact on the cycle time.
How is this time saving possible?
The measurement is now performed on the moving module during transport into the machine. By using a separate camera unit and its own illumination, the EL image acquisition and the image acquisition for the cell measurement are separated in time. This eliminates the time previously spent on additional EL camera image acquisitions and is a considerable time saver.
Due to the new position of the camera unit, the measurement is now located in front of the system in the gap between the MBJ conveyor belt and the upstream conveyor belt, all shadowing, e.g. due to the conveyor belt or the contact unit, is also avoided and the module can be measured over its entire surface without any restrictions.
The cell measurement works in transmitted light with a diffuse illumination that shines directly through the module into the cameras below. The illumination is 2.7 m long and 0.7 m wide and was commissioned as a custom illumination from MBJ Imaging.
In order to be able to fully measure the entire solar module while it is moving, many partial images of the solar module are taken in rapid succession. The captured images are directly transferred to the software and evaluated. The number of cameras depends on the length of the solar module to be inspected.
In the software, the cells and solder ribbons then appear dark against a bright background and can be measured. Here, not only cell distances but also distances to the glass edges and within the cross-connection are measured. The system can also detect breakouts at the cell edges and foreign bodies between the cells.