| 摘要 |
PURPOSE:To improve a sensibility of a gas sensitive element and to prolong a life of the element by holding the gas sensitive element in a state sandwitched between upper and lower electrodes and by providing a catalyzer on the upper electrode. CONSTITUTION:A heater 25 is attached previously at the back surface of a base plate 21 of electrical insulation and an Au lower electrode 221 is provided on most of the front surface. The gas sensitive body 23 consisting of thin film of SnO2 is provided by a spattering method so that it covers the most of the lower electrode and furthermore a porous Au upper electrode 222 is provided so that it covers the most of the body 23. A porous alumina layer 24 containing 1wt% Pt is formed successively by thick film printing method so that it covers most of the upper electrode. In the gas sensitive element constituted in such a way, thickness of the body 23 is decreased, the sensibility is improved and diffusion of the catalyzer into the gas inductive body and the reaction therewith are prevented and the life is lengthened. |
