ATW launches copper-printing equipment for solar cells

In Wuxi, China-based equipment maker Wuxi Autowell Technology (ATW) has launched a screen-printing solution for copper paste and silver-coated copper paste, targeting TOPCon, back-contact and next-generation solar cells.

The challenge is not simply swapping one metal for another. ATW says copper pastes have different sintering windows — the temperature conditions needed to form the contact — as well as different compatibility with glass frit and a greater need for oxidation prevention than silver pastes. Its equipment is built around three controls: precise printing, accurate alignment and controlled heating.

The line includes a cell printer, a base-metal print-on-print line for multilayer copper and silver-coated copper pastes, and a carrier-type curing furnace. ATW says the dual-track cell-printing line delivers a stable throughput of 10,400 wafers per hour and a cycle time of 0.68 seconds or less for 182 mm wafers. It supports wafer formats from 182 mm to 210 mm, including rectangular 210R wafers, and overlay accuracy within plus or minus 6 μm.

The furnace is the piece that addresses copper's vulnerability during curing. Its inert-gas atmosphere is designed to prevent oxidation, while its temperature-control system maintains uniformity within 5 C across four tracks. ATW says the transport system can work alongside its light-injection annealing furnaces and other supporting equipment.

So what changes in practice? The three-part offer combines cell printing, multilayer printing and controlled curing, rather than covering printing alone. That could make copper processes easier to move from material experiments toward mass-production lines, although ATW's throughput and accuracy figures are manufacturer claims.

ATW also plans a Solar Cell Metallization Laboratory with experimental lines and testing equipment for environmental reliability, electrical performance, material characterization and post-cell processing. The company says it will continue work on copper printing, print-on-print precision, furnace thermal optimization and handling ultra-thin wafers; its stated goal is to expand low-silver and silver-free process windows for customers.