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The TS3600 provides up to 55 containers for the various quality classes of solar modules.

An X20 CPU is the central controller for robotics, CNC and axis movements.

Testing 3,600 solar cells per hour and sorting with a 99.7% yield of good products and machine availability of over 95% - no other cell testing and sorting machine in the world does this as fast as the TS 3600 from Schiller Automation. The testing machine’s internal values are also worthy of acclaim: By using a motion control solution based on B&R technology, the system manufacturers from Germany’s Baden-Württemberg region were able to break their dependence on the higher-level machine/system controller during planning, development and sales of drive functions. This enabled the company to significantly reduce the engineering and manufacturing costs for the TS 3600 and future system generations.

“In the past, we were not able to simply transfer drive functions that we had already implemented on a specific system controller to a control solution based on a different type or manufacturer,” explains Thomas Wagner, developer at Schiller Automation GmbH & Co. KG. “This meant that our designers had to adapt the drive functions whenever designing a new system controller. This process sometimes took a good deal of time.”

Schiller Automation is not alone in this situation. Many manufacturers of special machines and systems are frequently confronted with this problem because clients who order custom system solutions - depending on their company history or the planned application of the production equipment - often require that a certain control supplier be used.

Reduced engineering time for drive functions

For the system manufacturer, these requirements mean becoming familiar with a variety of control environments. They also mean that guaranteeing specific (drive) functions or to delivery deadlines carries risks that are hard to estimate and unforeseeable additional costs. After all, at the time a contract for a conventional drive system concept is signed, it is generally not possible to foresee whether a certain drive function is even technically feasible with the customer’s preferred controller or which drive-motor combination must be installed in order to make it work.

It’s not hard to imagine why Schiller Automation GmbH & Co. KG started searching for possibilities to avoid the risks associated with changing controllers in the future.

This search culminated in an innovative motion control solution based on B&R technology, which provides uniform control of all drive-oriented functions in all of the company’s systems, while remaining independent of the higher-level system controller which is connected via TCP/IP. This essentially separated the controller and drive levels, which means that once a drive function has been created, it can be used again and again. “This standardization of drive functions reduces the variety of different hardware being used and therefore the complexity of the system. The functional safety and the reliability of our machines and systems are also increased proportionally. Technical sales representatives are also able to guarantee availability of functions that have been implemented in the past, without risk and without requiring lengthy research on the part of the Design Department,” points out Thomas Wagner, who is also responsible for the motion control concept at Schiller Automation GmbH & Co. KG.

Controller-independent drive solution

The company chose a CPU from B&R’s System X20 product series to run its motion controller, providing them with the comforts only found in a B&R solution. This makes it possible to combine robotics, CNC, linked axis movements and single-axis positioning in a homogeneous system, which is designed, implemented and commissioned a single engineering environment - B&R’s Automation Studio. The staggering number of different tools that were previously needed for engineering and maintenance are now a thing of the past. The time and money needed for training - as well as the associated hardware and software costs - are also accordingly reduced, as Thomas Wagner adds: “For example, when integrating CNC functions from other suppliers, the result is often additional tools and associated licensing fees and in the worst case even the need to change over to a considerably more expensive machine controller. With B&R, on the other hand, everything is covered by a single system. Thanks to the downward compatibility of the hardware and software, our customers are >>
able to benefit from B&R’s high potential for innovation, which also increases the security of their investment.”

During Schiller’s evaluation of potential motion control suppliers, this was not the only reason why B&R was able to prevail over six other suppliers. The flexibility of their solution was another key factor, reveals the expert from Schiller Automation: “The servo drives from the ACOPOS series enable us to group our drive systems the way we need them.” This ensures that different encoder systems can be used in the best possible manner. Only small individual modules must be replaced, while the basis deice remains the same.

Everything under one roof

The adaptability of the ACOPOS devices also provides clear advantages when integrating the different motor types. This also came in handy on the TS 3600, which has more than 30 axes, because the testing and sorting machine uses both rotary motors as well as linear drives, stepper motors and torque motors from different manufacturers and a wide range of encoder types. These can now all be driven using devices from the ACOPOS series.

Thanks to this high-performance and adaptable motion controll system and a completely newly developed transport system, the testing and sorting machine is easily able to process 3,600 wafers per second. As soon as testing equipment becomes available that is able to provide faster electrical and visual analysis, this throughput could be increased even further. A convenient interface not only allows the user to integrate specific testing equipment in advance, it also makes it possible to exchange the equipment down the road if necessary.

Innovative transport system ensures optimum testing results

To ensure the best possible results, the testing machine’s innovative transport system uses a vacuum to straighten the wafers, which become slightly arched during the production process. This ensures that the lens system of the visual testing device has the best possible view of the wafers in order to prevent off-focus image sections. The transport system also ensures that the wafers maintain their defined position while running through the testing machine, to produce more reliable and reproducible measurements.

This is fundamentally important for the user because the measurement results directly affect the amount of profit that can be achieved. The testing machine not only identifies and rejects defective cells, it also surveys and divides the solar cells into different quality classes (the TS 3600 provides up to 55 container spaces for this) based on the determined parameters such as power, open-circuit voltage or short-circuit current.

The TS 3600 combines the reliability of the measurement results with extremely careful handling of the solar cells, to achieve the record-breaking 99.7% yield of good parts. The engineers at Schiller Automation were able to achieve these results by reducing the number of required transfers to an absolute minimum and developing a new method of contact for the electrical test of the solar cells, which accounts for the exact cell position and the remaining arching of the wafer and establishes electrical contact with the testing equipment using a monitored amount of force.

To summarize, an innovative motion control concept based on B&R technology and countless other innovations enable solar cell manufacturers and processing companies to increase their productivity with the cell testing and sorting machine from Schiller Automation and to significantly lower the total cost of ownership (TCO).