Moisture getting composition for hermetic microelectronic devices

Abstract

This invention describes a composition of matter having moisture gettering properties and applicable as coating or adhesive in a hermetic microelectronic device. The composition is applied to the interior surface of the packaging at a thickness of 0.1-25 mil and comprises a desiccant finely dispersed in a binder which is a water vapor permeable solid material. This may be a polymer, porous ceramic or glass. The desiccant is a particulate solid with 0.2-100 micrometer average particle size. It ought to be able to absorb from a one atmosphere pressure gas containing one volume percent water vapor at least four parts by weight of water vapor per 100 parts by weight of desiccant at 25.degree. C., and for high reliability devices, it should also be able to absorb at least two parts by weight of water vapor per 100 parts by weight of desiccant at 100.degree. C. The desiccant to binder volume ratio ought to be between 0.002 and 2. Molecular sieves are especially useful as the desiccant component of the composition of this invention.

Dependencies are inferred from the claim text.