| 摘要 |
PURPOSE:To calcine a ceramic substrate without generating difference of characteristics between a front and rear surface of the substrate by calcining the substrate in a calcination furnace in a state of floating the substrate from a hearth plate. CONSTITUTION:A ceramic substrate 8 is mounted on a hearth plate 6 of a calcination furnace 1 constituted of an upper furnace 2 for calcination and a lower furnace 3 for heating gas such as air. The gas such as air is introduced in a direction of an arrow mark A from a gas introducing port 9, reaches the upper furnace 2 via gas passing holes 7, and discharged in a direction B from a gas discharging port 10. Since the amt. of the gas introduced through a gas introducing port 9 is little in the calcination stage, the ceramic substrate 8 is not floated up or hardly floated up from a hearth plate 6. When the calcination is proceeded to a final calcination stage and the amt. of introduced gas is increased, the ceramic substrate 8 is floated up completely and the calcining gas is distributed uniformly on both sides of the substrate. Thus, an org. binder is removed completely, satisfactory impregnation and diffusion of O2 are attained. |
