Solar Cell Wafer Inspection

A wafer is a thin slice of silicon with semi conductor properties. It is the key component in a solar cell, which convert sunlight into electricity. The company was established in 1994 and has all its production in Norway. ScanWafer's production capacity has increased tremendously during the last years. The second production line in Glomfjord was started in 2001 and a new plant at Herøya starting up in 2003. The newest production lines are far more efficient than the first one in Glomfjord. Together with the equipment suppliers, new and more cost effective production equipment have been developed.

The Challenge

Tordivel was challenged to develop a high end vision system for quality inspection of the wafers before packing. The system should do advanced gauging, surface inspection as well as edge and breakage control. Due to the innovative nature of automatic wafer inspection the requirements for inspection is changing over time.

Our solution

The vision system is integrated in the Wafer Lines from Tronrud Engineering AS. Through several inspection stations, both sides of the wafer are checked within the cycle time of two seconds. A Scorpion firewire imaging solution is running on standard PCs equipped with Sony high resolution Firewire cameras. Switching of advanced illumination and communication to inspection line PLC as well as to plant CRM system, has been solved through standard interfaces in Scorpion. New inspection tasks, extensive data logging and realtime reporting has been added when requested, tailor-made to Scanwafer's exact requirements, showing the flexibility of Scorpion without programming, upgrading only with configuration changes.

The results

Tordivel has in good cooperation with the customer been able to comply with the rapid growth and demand to the inspection systems during start up of new production facilities.

Øivind Gjerstad, Technical Director of ScanWafer says : "Tordivel has been a valuable supplier and partner bringing solutions to a challenging production task. The Scorpion inspection system has brought us forward in the challenging task of automatic product inspection. The flexibility of Scorpion Vision Software has proven to be important to cope with the increasing demand for reporting and the application of statistical methods in process improvement."

"It is important to have suppliers with standard tools, but also with competence to support the operation during the difficult start-up phase for a plant with new and demanding technology" concludes Gjerstad.

The systems are running 365 days a year, 24 hours a day in the plants in Glomfjord and Herøya in Norway with frequent follow up by Tordivel via a remote tcp/ip connection. This makes the support efficient and cost effective for the customer.

 

Sawmark detection

 

Solar cell wafer inspection data sheet - 403 kByte pdf

 

Wafer Measurement

The scope is to check wafers for defects and providing measurement and sorting data. This with the highest reliability and accuracy, low maintenance cost and the best total cost of ownership.

3D Wafer Block and Ingot Measurement

The Scorpion 3D Scanner, makes accurate 3D models of wafer blocks and Ingots, measuring the size and detecting defects with a resolution down to 0.01 mm.