Germany’s need for solar power is growing and soon conventional production processes will not be able to meet demand. Currently, solar cell sheets are fabricated using a partly manual flatbed screen printing process, which can cause bottlenecks. The Fraunhofer Institute for Solar Energy Systems (ISE) has therefore joined with industry partners to develop a faster rotary printing process that will dramatically improve throughput.

In the Rock-Star and Rock-IT research projects, the Fraunhofer ISE, ASYS Automatisierungssysteme GmbH and partners have developed a demonstrator machine for the metallization of silicon solar cells and other electronic components. The innovative roller printer is capable of increasing throughput by a factor of 1.5. “The machine has the technical potential to double the throughput compared to screen printing machines,” explains Dr Andreas Lorenz, project manager at Fraunhofer ISE in a press release.

The new machine features a high-throughput transport system: the flexible units and components for printing are transported on autonomous shuttles at high speed and with precision through various rotary printing stages. Depending on requirements, either a flexographic printing unit or a rotary printing unit can be used for metallization. In a proof-of-concept demonstration, the team achieved a cycle-time of just 0.6 seconds per solar cell, compared to 0.9 seconds per cell using flatbed screen printing.

The potential uses are not limited to solar cells: the machine can also be used for functional printing in the fields of fuel cell technology, sensor technology and power electronics including circuit boards, chip cards and other components.

The projects were funded by the Federal Ministry of Education and Research (BMBF) and the Federal Ministry for Economic Affairs and Climate Action (BMWK, formerly BMWi).