Moisture getting composition for hermetic microelectronic devices
First Claim
1. A composition of matter useful as a desiccant in a hermetic electronic device, comprising a powder dispersed in a binder, whereinsaid powder is selected from the group consisting of zeolite molecular sieves, activated alumina, silica gel, alkaline earth oxide, and alkali metal carbonate;
- said binder is a continuous matrix of porous glass or porous ceramic; and
said powder to binder volume ratio is 0.001-2.
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Accused Products
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° 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° 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.
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Citations
7 Claims
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1. A composition of matter useful as a desiccant in a hermetic electronic device, comprising a powder dispersed in a binder, wherein
said powder is selected from the group consisting of zeolite molecular sieves, activated alumina, silica gel, alkaline earth oxide, and alkali metal carbonate; -
said binder is a continuous matrix of porous glass or porous ceramic; and said powder to binder volume ratio is 0.001-2. - View Dependent Claims (2, 3, 4)
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5. A composition of matter useful as a desiccant and particle getter in a hermetic electronic device, comprising a powder dispersed in a binder, wherein
said powder is selected from the group consisting of zeolite molecular sieves, activated alumina, silica gel, alkaline earth oxide, and alkali metal carbonate; -
said binder is a polysiloxane or polyurethane gel which is effective as a particle getter, and said powder to binder volume is 0.001-2. - View Dependent Claims (6, 7)
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Specification