| 摘要 |
PURPOSE:To improve the holding strength of the sintered body of a metal oxide semiconductor, by selecting the thickness and the clearance of a flame coating film. CONSTITUTION:A sintered body 8 of a gas sensitive metal oxide semiconductor is contained in a cavity 6, which is provided in a heat resisting insulating substrate 2, with a gap being provided. The sintered body 8 is fixed to the cavity 6 with a ceramic flame coating film 24. For the flame coating film 24, any of fine or porous material can be used. In order to prevent the decrease in response characteristic of a sensor due to the flame coating film 24, it is desirable that flame coating is performed only on a part of the surface of the metal oxide semiconductor. When the sintered body 8 is contained in the cavity 6, the gap having a certain size is required in consideration of errors in sizes of the sintered body 8 and the cavity 6, difference in thermal expansion coefficients of both parts and the like. The radio between the width of the gap, i.e., the clearance and the thickness of the flame coating film 24 is important. When the ratio is made to be 0.6 or more, cracks are not yielded in the flame coating film 24, and the sintered body 8 can be sufficiently held in the cavity 6.
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