Filtration in photovoltaic industry (PV-Industry)

Recycling of process fluids and waste water treatment

Since 2006 Atec is involved in the solar wafer business with its solutions for treatment of process fluids. For example extending service life of wafer pre wash baths, recycling of cutting fluids / coolants, and the waste water treatment as well as removal of silicon particles.

Some of these tasks are elaborated in some details below. Please contact us in case of questions or for the discussion of new challenges.

Wafering using diamond wire technique

The former SiC-slurry based “sawing” process is replaced step by step by modern diamond wire wafer sawing processes using different kinds of cutting fluids. The latter requires also new solutions in respect to process fluid treatment equipment and the respective processes. In the recent years Atec is cooperating with leading manufactures in the field to be able to supply the necessary equipment.

Recycling of cutting fluids

To recycle water based cutting fluids silicon particles have to be removed while at the same time certain components must not be removed from the fluid. This has to be ensured by using membranes with suitable (molecular weight) cutoff. A high resulting cross flow and wherewith a minimal filter cake thickness is crucial for an economical operation of. This can be achieved using Atec Filtration units – even with high solids concentration.

Benefits of cutting fluid recycling

  • Optimal and constant production conditions
  • High product quality
  • Reduction of use of chemicals
  • Reduction of use of fresh water
  • Savings on disposal costs
  • Less economical damage

Reduction of COD in waste water of silicon wafer production

One has to face completely different challenges if it is the task to only use a cutting fluid once. Next to removing the silicon often the chemical oxygen demand (COD) of the waste water has to comply with local regulations. Special Atec filtration plants using nano filtration (NF) modules can help to reach this goal.

Atec offers central solutions as well as small standalone units

For the treatment of whole production units (wafering lines) often central solutions are preferred. For process development (e.g. test of new cutting fluids) Atec can also provide small standalone filtration units to be operated next to a diamond wire wafer saw.

Besides the filtration units Atec offers all necessary equipment like such for silicon particle removal as well as automation of the total system.

Benefits of Atec filtration units

  • Small footprint
  • High energy efficiency
  • High solid silicon concentrations are reached due to their high cross flow