Semiconductor package with integral hermeticity detector
AssigneePlessey Incorporated
InventorsLawrence E. Frazee, Anthony V. Fraioli
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Abstract
The operation of relative humidity sensors made from cobalt oxide on a non-conductive ceramic substrate is improved by heating the sensor for a short period to a high temperature in a reducing atmosphere. This reduces the specific resistance of the device. With a lower resistivity, it is possible to reduce the size of the sensor to the point where it can be included along with a semiconductive device in standard hermetic packages. This makes possible the continuous, one-line monitoring of hermeticity for the life of the circuit without the necessity fo applying a load to the circuit.
Claims4
A hermetically-sealable package for a semiconductive device including an integral hermeticity detector comprising:
- means forming a cavity adapted to retain said semiconductive device and including a dielectric substrate;
- a plurality of metallic leads extending from within said cavity to the outside of said package;
- a humidity sensor within said cavity, said sensor comprising a double-fired layer of cobalt oxide, said layer having a lower than normal resistivity as a result of a second firing in a reducing atmosphere at about 1500.degree.C. for a brief period;
- a pair of electrodes on said double-fired layer connected to a pair of said leads;
- and
- seal means for hermetically sealing said cavity.
Dependencies are inferred from the claim text.