Complete Inspection of Solar Strings with STRING-Q EL / VISION

Increase Production Yield with Automatic Detection of Bad Parts for Rework

Requirements & Targets

100 % automatic inspection of EL and optical image for reliable process control and quality check

  • Detect micro cracks and electrical cell problems
  • Detect cell breakage caused by stringing
  • Check tabbing position and alignment with busbar
  • Check alignment of cells in string and straightness of string
  • Obtain precise positioning information for lay-up

Inspection Solution


  • Detection of electronic and optical defects after stringing
  • Easiest integration into state-of-the-art module production lines
  • Optical inspection with < 80 μm per pixel, EL down to < 100 μm per pixel
  • Cycle times as low as 5 sec. per string

System Application

100 % automatic in-line inspection of strings before lay-up

  • STRING-Q EL / STRING-Q VISION integrated after stringing machine and before lay-up
  • Automatically check each string for defects
  • Sort-out defective strings for rework
  • Determine string position and hand-over coordinates for precise lay-up
  • Zero defect tolerance with the highest yield (99.9 %)

Benefits for Production

Key to cost-efficient module production

  • Robust and reliable automatic detection of optical and electronic defects
  • Better quality and higher production yield with more control of stringing process
  • Lower production costs and better material usage with automatic optical inspection, sort-out and rework