| 摘要 |
PURPOSE:To obtain in high productivity the title substrate sheet free from warpage by calcination of a combination of ceramic green sheets with the warpage direction opposite to each other in the calcination. CONSTITUTION:Ceramic green sheets 12, 14, 16, 18 are formed, e.g., by doctor blade technique, with their forming directions of arrows 12a, 14a, 16a, 18a, respectively. Film sheets 20, 22 used in the above forming are directly applied on the upper and lower surfaces of the sheets 12, 18, respectively, and the sheets 12, 14, 16, 18 are arranged as shown in the figure so that their forming directions are made alternately rectangular and laminated under pressure followed by integral calcination. At this time, because of the vertical difference in the packing density of ceramic granules in the direction of the thickness, the sheets 12, 14 and the sheets 16, 18 tend to bend upward and downward, respectively. Thereby the warpage in the calcination will be canceled or suppressed, thus obtaining the objective ceramic substrate free from warpage and good in surface smoothness. |
