This month, STS continued to capture operator’s errors leading to non-conforming (and therefore rejected) products. Module cracks caused by bumps in the encapsulant when manually fed into the assembly line, back-sheet accidentally damaged by mishandling, and encapsulants swapped because the label was not properly read are a few of the common issues that the STS Team captured this month.
We also witnessed a manufacturing line removing the operator responsible for quality check at the electroluminescence station when STS inspectors were leaving the production line. The “fridge paradox”: no one knows whether the light is on when the fridge is closed!
De-soldering/over-soldering caused by equipment failures is a very common defect captured in our inspection. This non-conformities is sometimes hard to capture during the EL tests. EL parameter checks at every shift is critical! This defect type may reveal itself only after transportation, or after a few weeks or months of thermal cycling in the field. This month again, our field-testing crew found brand new modules with a soldering defect rate of more than 10% (modules were not manufactured under STS production supervision).