Reis Solar Systems Laser Soldering

The system supplier for photovoltaic module lines, Reis Robotics, has implemented a newly developed laser soldering procedure for practical use with several customers.

Photovoltaics manufacturers are increasingly anxious to fully exploit the automation potential of their production in order to deal with the increasing demands for lower prices. REIS ROBOTICS, as system supplier, with its subsidiary Reis Lasertec as laser welding specialist has been successful for some years in the practical implementation of these very complex application tasks.

DESCRIPTION

A newly developed laser soldering method ensures further increases in quality, shortened cycle times and reductions in manual rework. An integral process controller monitors and documents the production process.
In doing this, it is possible to concentrate the heat input such that soldering can be done directly on the EVA foil. With direct soldering on the foil, unnecessary multiple handling of the strings during the pre-process is avoided.
The integrated process control offers further advantages - it monitors the soldering of each joint individually and the data from this can be transferred and saved in a database for later documentation and quality control.  Furthermore, faulty solder joints are reported directly via a monitor at a subsequent work station so that a worker recognizes these immediately and can manually resolder.

INNOVATIVE ASPECT

With our concept the have less strain on the matrix, because the strings are handled only once and no multiple handling is required.

Besides this, we almost achieved half of the total cycle time contrary to conventional methods.  The high flexibility of the system furthermore allows various module sizes due to fast setting. The complete cell is pre-mounted on a Reis assembly plate and as complete unit can simply be retrofitted in existing systems. Thus, a possibly required interruption of production will be reduced in case of retrofit in existing systems.

This is what makes REIS LASER SOLDERING different from competitors' systems on the market: high flexibility, speed, and high quality of the end product. Particularly with regard to costs for the required material, there is a direct correlation between the quality or tolerances and costs.

BENEFITS

This laser soldering system offers decisive advantages compared to other procedures:

• robot system optimized for soldering of cross contacts
• soldering of the cross contacts with the cell contacts directly on the layup consisting of glass and EVA-foil
• low mechanical strain of the soldering joint
• exact control of the soldering temperature and capacity
• optimization of quality
• high traction forces > 10 N, determined acc. to DIN EN 50461:2006
• high speed soldering system
• integrated process monitoring with evaluation of the soldering quality
• determination of the soldering points by means of an integrated image processing system, process safety with regard to position tolerances of the components and soldering points
• with FDA-permission for use in the USA

The most important advantages of these systems are precision and high service quality. To improve the quality of the end product and higher throughput of production as a consequence to avoid multiple handling of the strings and cells.