| 摘要 |
<p>PURPOSE:To adjust an atmosphere in a firing vessel optimally, and to obtain a voltage non-linear resistor having excellent stable electrical characteristics by setting the ratio of the internal volume of the firing vessel to the overall volume of fillers containing at least bismuth oxide and antimony oxide within a specific range in a baking process. CONSTITUTION:A calcined body on which an insulating coating layer is applied is put in an alumina, mullite or magnesia firing vessel 11, to which a lid is attached and an opening section is not formed. The bottom of the vessel 11 is covered with a planking 15 having approximately the same composition as a plurality of the calcined bodies, articles to be fired 13, and covered uniformly with laying power 17 having approximately the same composition as the calcined bodies 13. A fixed number of the calcined bodies, the articles to be fired 13, are placed on the layer powder 17 at regular intervals. The ratio V/A of the overall volume V of the plankings 15, the laying powder 17 and the articles to be fired 13 having the same composition to the internal volume A of the firing vessel 11 is set 0.07<=V/A<=0.55 at that time. the ratio is set within a range of 0.1<=V/A<=0.3 more preferably. Accordingly, an atmosphere in the firing vessel is optimized.</p> |
