Singulus develops new diamond wire multi wafer texturing process

Singulus Technologies, the German-headquartered machinery and tooling supplier to the solar industry, has developed a new process that integrates diamond wire sawing into the company’s LINEX inline system for the processing of multicrystalline wafers.

This process, the company says, can reduce manufacturing costs and improve the efficiency of solar cells made using multicrystalline wafers.

Singulus believes that the growth of the multi-wafer market witnessed in 2017 will continue into 2018, with a market potential in excess of 70 GW. By producing multi wafers using diamond wire saws, the costs per wafer can be reduced significantly, while the environmental impact is far less damaging than using the more conventional slurry process, which uses oil and silicon carbide.

The LINEX inline system developed by Singulus incorporates a texturing process that removes the saw marks made by the diamond wire on the wafers when cut. The innovation is a two-step process using new additives and ozone for post-cleaning to create a homogenous structure, said Singulus.

“The texturing of solar wafers is a manufacturing step that has a major influence on the efficiency of the solar cell,” said Singulus CEO Stefan Rinck. “We have equipped the innovative LINEX inline processing system for wet-chemical surface treatment with the new combined process, which means we can bring costs down significantly while also improving cell performance.”

Singulus has also developed a new conveyor system in the LINEX inline processing tool that the company says guarantees “extra-gentle” handling of the multi wafers, thereby delivering a marked reduction in breakages. Unlike mono wafers, multi wafers can become fragile when sawn, leading to problems with texturing.

By incorporating these added steps to the multi texturing process, Singulus joins fellow German production manufacturer Schmid in offering such a process for multicrystalline wafers.

The growth in the mono wafer market over the past 12-18 months can be traced to the earlier introduction of diamond wire sawing of monocrystalline wafers – with companies like Meyer Burger leading the way and China’s LONGi opting for mono-only module portfolios.