High-porosity thick-film getters

A new getter family is presented based on highly porous getter coatings that have a thickness range of 50-150 mu m. They are obtainable on almost any metallic surface (even device parts) and are suitable as a solution to meet special geometry and high sorption speed requirements. In order to become active, the getter material must be heated in vacuum at a suitable temperature and for a time that can be selected to be compatible with the various application constraints. Two different getter compositions are presented: one that can be activated at relatively high temperatures and another useful for application where activation can only be performed at relatively low temperatures. The pumping performances of these getters for various gases (CO, H₂, CH₄) at different working temperatures (25 and 150 degrees C) have been studied. The influence of coating thickness on the getter sorption characteristics was also investigated. The good mechanical stability of this family of getters, mainly due to the sintering process they undergo, is also discussed.