One of the critical performance parameters of photovoltaic (PV) cells is the cell efficiency. Testing cell efficiency is not only important for control of the manufacturing process, but it is also required in the following steps to assemble the cells into panels. The client, a startup solar PV manufacturer, had developed a unique, low cost method of manufacturing PV cells. The efficiency test was conducted with a flash tester that generates an I-V performance curve. The client needed a solution that made the necessary measurement and met their throughput and reliability requirements.
In developing a solution for the client, it was critical that the measurement performance of the test not be compromised. The efficiency measurement is an industry standard with exacting requirements for spectrum, intensity, and uniformity. The automation needed to accommodate multiple cell form factors with multiple output lanes for sorting. The ideal solution would be to integrate a flash test head from a known manufacturer with custom, high throughput automation that met the needs of their factory.
Working closely with the client, Owens Design was able to develop a system that integrated an industry standard I-V flash test head with custom automation that met the high throughput and reliability the client needed. Two input lanes and multiple output lanes were used to handle and sort the cell carriers. Custom handling automation was developed to expose the cell to the I-V test head, make electrical contact to the cell, and off load to the sorting mechanisms. System software was developed to test, qualify, and sort the measurement results.