How does LG ensure there are no micro cracks in their panels?

All LG modules are tested via an Electroluminescence "EL" inspection after manufacture. The EL inspection is effectively a special photo which highlights and detects micro-cracks invisible to the naked eye. All panels are 100% EL test checked for quality control. If any micro cracks are detected, the solar module is rejected and cannot be sold. All LG panels that leave the factory are micro crack free. EL testing together with 'flash testing' of panels to confirm their performance are two of the ways LG ensures it's panels are defect free, long lasting and high performing.