Integrating Ionization into Fan Filters With Distance Restriction to the Wafer Plane Posted May 7, 2019 by TES Team & filed under Custom Fan Filters Blog, Products. Using the "Dual Zone" filter for FFU Ionization Since the ionizer in a front end is located right under the filter and in fact the airflow carries the ions to the wafer plane, it is natural to see the ionizer integratedread more