Waste gas treatment for the TFT industry
Manufacturing TFT/LCD displays requires waste gas treatment as well. Processes that produce large scale Thinfilm Transistors (TFT) on glass substrates, for instance, use Chemical Vapour Deposition – CVD – to separate the thin films onto the material. The process requires cleaning the process chamber periodically and usually employs etching with NF3. Etching of the separated thin films typically utilises CF4, SF6 and chlorinated gases, which release large amounts of waste gas mixtures.
In addition to the etching gases mentioned above, waste gases accrued in production processes of the TFT/LCD industry contain residuals of process gases silane SiH4, ammonium NH3 and nitrogen oxide N2O. Some of these substances are highly caustic, are toxic or highly flammable. The perfluorinated hydrocarbons, moreover, are considered greenhouse gases that have an extremely high global warming potential.
These waste gases therefore pose a significant risk to the environment, but also to the safety of the production facilities. Merging different waste gases in the factory’s central waste gas system often creates highly flammable or highly explosive gaseous mixtures, which pose a serious safety hazard and hence must to be avoided at all times. Aggressive gases also contribute to the accelerated corrosion of pumps, valves and pipes to further compromise the facility’s safety. And small particles contained in the waste gas stream can deposit inside pipes and clog them, causing increased maintenance or even a complete production shutdown.
Systems designed by DAS Environmental Expert clean the process waste gases directly at their point of origin (Point of Use) and abate the hazardous substances reliably. DAS has developed solutions specifically for the TFT/LCD industry to safely handle large volumes with exhaust gases meeting the standards of the TA-Luft (German Clean Air Regulations).
DAS waste gas abatement technology is based on a flexible, integrated system concept. Our smallest equipment fits into a closet of less than 1 square metre footprint. DAS technology is fully automated and sensor-controlled and meets the highest certified safety standards. DAS Environmental Expert has more than 14 registered patents in the field of waste gas abatement and owns additional usage rights for important technologies and technical solutions.