Advanced Inline Quality Control (IQC) - Novel Concepts for Quality and Process Control of Crys- talline Silicon Wafer and Solar Cell Production Lines

摘要

Quality control in solar cell production lines for a long period was focused on sun simulator testing results. Detailed analyses of the IV curve (under different illuminations and dark) give an overview of the loss mechanisms. With increase average efficiency goals for novel production lines a much more detailed analysis of every single production step is needed: Incoming quality control, inline quality control, process control and detailed classification is needed together with statistical process control to assure further improvement of efficiency, throughput, mechanical and electrical yield and product quality of solar cells and modules. The paper describes actual concepts and techniques for all of these topics, starting with wafer quality inspection by a wafer inspection system (WK). Next QC-steps are optical inspection of the etching and texturisation process followed by electrical inspection of wafers after diffusion. Optical inspection systems after ARC, printing and as final classification tool play an important role as well as μ-crack detection and stability testing. A collection (often using OPC connections) and specific sorting of all selected data via a central PC and a centralized database is finally the latest status of IQC and process control.