초록 ▼

A device comprising a dielectric oxide film formed by anodization of a surface region of a valve metal body, a semiconductive metal oxide layer porously formed on the dielectric oxide film, and a gas permeable electrode layer formed on the semiconductive metal oxide layer with the interposal of a ga

A device comprising a dielectric oxide film formed by anodization of a surface region of a valve metal body, a semiconductive metal oxide layer porously formed on the dielectric oxide film, and a gas permeable electrode layer formed on the semiconductive metal oxide layer with the interposal of a gas permeable carbon layer therebetween. The semiconductive metal oxide layer is formed by pyrolysis of a metal salt solution so as to be, microscopically, only partially in contact with the dielectric oxide film. After forming of the electrode layer, the device is immersed in boiling water and/or kept in a high temperature high humidity atmosphere for an adequate amount of time to stabilize the semiconductive metal oxide layer, resulting in that the semiconductive metal oxide layer has a multiplicity of microscopic crevices and that the device becomes quite stable in the relation between humidity and electrostatic capacitance of the device.

대표청구항 ▼

A method of producing a humidity sensing element of a capacitance change type, the method comprising the steps of: (a) anodizing a valve metal body to form a dielectric oxide layer film on a surface of said metal body; (b) forming a semiconductive metal oxide layer which is gas-permeable on said die

A method of producing a humidity sensing element of a capacitance change type, the method comprising the steps of: (a) anodizing a valve metal body to form a dielectric oxide layer film on a surface of said metal body; (b) forming a semiconductive metal oxide layer which is gas-permeable on said dielectric film by thermal decomposition of an aqueous solution comprising a thermally decomposable metal salt applied to said dielectric oxide film; (c) forming a gas-permeable layer of carbon on at least a portion of the outer surface of said semiconductive metal oxide layer; (d) forming a gas-permeable and electronically conductive layer on said layer of carbon by applying a paint comprising a metal powder and a synthetic resin as a binder to the outer surface of said layer of carbon; and (e) subjecting the product of step (d) to a vapor phase treatment for a period not shorter than 30 hours at a relative humidity of not lower than 90% at a temperature not lower than 80°C.