Thick film getter paste compositions with pre-hydrated desiccant for use in atmosphere control

Abstract

The invention is directed to a process for making screen-printable getter composition comprising: (a) glass frit; and (b) pre-hydrated desiccant material; dispersed in (c) organic medium. The present invention further relates to a getter composition utilizing low-softening temperature glasses comprising, based on weight %, 1-50% SiO2, 0-80% B2O3, 0-90% Bi2O3, 0-90% PbO, 0-90% P2O5, 0-60% Li2O, 0-30% Al2O3, 0-10% K2O, 0-10% Na2O, and 0-30% MO where M is selected from Ba, Sr, Ca, Zn, Cu, Mg and mixtures thereof. The glasses described herein may contain several other oxide constituents that can substitute glass network-forming elements or modify glass structure. The desiccant material is pre-hydrated to reach its saturation level of moisture absorption. The process of pre-hydration can be done by exposing the desiccant in a normal temperature/humidity environment of for example, 25° C. and 50-60% RH. For 24 to 48 hours or up to the time when weight gain (due to moisture absorption) stops increasing. An accelerated hydration process in a chamber with higher than normal humidity level (i.e. 50% Relative Humidity) is also applicable to shorten the time of exposure to fully hydrate the desiccant material.

Dependencies are inferred from the claim text.