Product Briefing Outline: Komax has developed an extensive product portfolio of testing equipment within its ‘Xinspect’ series. It combines three testing procedures in one equipment backlight and electroluminescence inspection and completes these results with monochromatic I-V curve measurement. These approaches allow having a robust automatic quality inspection during module production in-line as well as off-line. These technologies are also applicable for thin-film modules.
Problem: Currently, many defects that impact the peak power of the module are not seen during production or are not measured after each process step. As a result, power losses are detected on the finished module where it is too late to find out which process in detail caused the problem. Furthermore, it is also too late in the process to perform some reparation. Since the cells are electrically connected in series and one single cell, which is partly not working, can significantly impact the salable peak power of the module, there is huge interest to get immediate and detailed information about the process quality during module production. However, the final criteria in module production are the values of the sun simulators and the resulting I-V curve. In order to include a sun simulator after each process, a very high investment would be needed and often the space requirements make such an approach unrealistic.
Solution: In addition to the classic backlight image processing approaches, electroluminescence testing highlights important normally invisible defects, such as microcracks, dark area, and printing defects. Not all of them have the same electrical performance impact. Some might propagate to a more important defect later, others have a direct correlation to electrical performance, and others might even be ignored. Consequently, the additional verification of the electrical performance by a monochromatic I-V curve measurement facilitates a cost- and space-optimized solution. The monochromatic I-V curve also allows for a relative measurement system to distinguish good and defective units by setting a previously determined acceptance threshold. In such a case, repeatability is more important than absolute values.
Applications: String testing stand-alone (Xinspect 3000s); string testing fully integrated in layup system GL30 (Xinsepct 3500ic); stand-alone module testing prelamination, postlamination without junction box, postlamination with junction box (Xinspect 4000s). In-line module testing prelamination, postlamination without junction box (Xinspect 4000i).
Platform: Electroluminescence and I-V curve measurement are available separately. Detection results and EL images are all stored in a database for further detailed statistical analysis. Customer specific information such as cell type, batch number, and other tracking information can be stored with each measurement either manually or by barcode reader. For each connection type, a simple tooling system allows for quick changeover.
Availability: Currently available.