Delivery of the first TinPad systems is planned for September. Using the Schott patented technology it is now possible to produce completely silver-free backside contacts with a peel-off strength which is twice as high as required. By using tin instead of the conventional silver/aluminum paste, savings of US$0.06 cent per wafer are achieved, which makes amortization of the investment possible in seven to nine months.

Schmid says this new backside architecture increases the cell efficiency by approximately 0.2 percent, because openings of the aluminum backside are no longer required for the busbars. The all-over back surface field thus increases the open circuit voltage which in turn boosts efficiency.

The first version of the TinPad system realizes a throughput of up to 2,880 wafers with an uptime of over 95 percent as the company claims and is easy to integrate in existing cell production lines. Module manufacturers can also use this technology and thus increase their value chain.