The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 13, 1993
Filed:
Aug. 13, 1990
Toshitaka Matsuura, Aichi, JP;
Keizo Furusaki, Aichi, JP;
Mineji Nasu, Aichi, JP;
Akio Takami, Aichi, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
The invention relates to a method of producing a gas sensor element having a porous film formed by a thick-film technique on a ceramic substrate surface so as to cover selected portions of electrode films precedingly formed on the substrate surface. The electrode material is a noble metal such as platinum. Both the electrode films and the gas sensitive porous thick-film are formed by known methods. To improve the contact between the gas sensitive porous thick-film and the electrode films both mechanically and electrically and stabilize the internal resistance of the sensor element by depositing a noble metal such as platinum at the interface between the porous thick-film and each electrode film, the porous thick-film is impregnated with a solution of a noble metal compound such as chloroplatinic acid and thereafter maintained in a reducing gas atmosphere having a controlled humidity in the range from 5 to 90% (relative humidity) at a temperature in the range from 10.degree. C. to 135.degree. C.