Concise description

2D code readers from SICK identify solar panels using a code lasered onto the glass substrate to ensure the removal of N.O.K. panels.

Task

Manufacturing of solar panels based on thin-film technology is rapidly advancing. Production has increased more than twenty-fold since 1999 to around 4,300 megawatts at present and, between 2007 and 2010, the market share has doubled to 20%. At the same time, a fall in prices can be observed in photovoltaic products, which has in turn placed pressure on manufacturers to develop efficient and innovative production programs. A key measure here is continual control and checking of process steps, with regular identification of panels during the manufacturing cycle being a must. Reflections from the substrate and the system, variations in optical images depending on the process step, code contrast plus positional tolerances when handling the panels mean high requirements for the reading technology used, which also needs to be suitable for integration in field bus environments.

Implementation

2D Code Readers identify thin solar modules in demanding environments using their lasered code, thereby guaranteeing efficient process control and continual 100% tracking.

The thin solar modules are identified using a high-performance 2D code reader (ICR845-2) from SICK. The latest CMOS technology combined with an integrated light guarantees reliable identification of 14 x 14 mm codes using just 0.7 mm in dot size. A single sensor variant is sufficient for mastering all the different read situations. If the integrated light is not sufficient owing to extreme reflections, an external light is also available.

Commissioning of the code reader is made considerably simpler and faster by Auto-Setup configuration, live images and evaluation of read results using a convenient diagnostics function. During operation, the code readers' short evaluation times enable thin panels moving at 0.5 m/s to be identified in an optimized process. The 2D code reader is also designed to enable flexible connection to automation and communication systems such as CAN, RS-232, Ethernet and various field bus connections.

Customer benefits

With the 2D code readers from SICK, users can identify all panels reliably, thereby enabling maximum process and product quality. This prevents costs for delivery and installation of faulty modules and resultant compensation claims. In addition, the reading devices provide maximum system availability as data and parameter sets are retained even in mains voltage failures, with read data made available again immediately on system restart. The code readers do not even need to be reconfigured during changeovers, which minimizes system downtime and hence costs.

Identification, control and tracking of individual panels enable production buffers to be set up for the production process so users can optimize system utilization and throughput. This results in greater freedom for production and logistics since, continual identification of panels means only original solar modules made by the manufacturer will be supplied and installed, enabling unjust complaints due to copies for example to be recognized immediately.