| 摘要 |
PURPOSE:To reduce the warpage of a multilayered ceramic substrate without preparing a dummy pattern and pressing products during a sintering process by constituting the upper layer of the substrate provided with a sealing pattern of green sheets having smaller coefficients of contraction and the lower layer of green sheets having coefficients of contraction larger than those of the green sheets for the upper layer. CONSTITUTION:Since the upper layer provided with a sealing pattern 1 of this multilayered ceramic substrate generally contracts more than the lower layer does, warpage takes place in the ceramic substrate after sintering due the difference in coefficient of contraction between the upper and lower layers. Therefore, the upper layer is constituted of green sheets 5-7 having smaller coefficients of contraction and the lower layer is constituted of green sheets 8-10 having coefficients of contraction which are smaller than those of the green sheets 5-7 by, for example, 0.2-0.6%. As a result, the conventional difference in coefficient of contraction between the upper and lower layers is eliminated and the warpage of this multilayer ceramic substrate is reduced. Therefore, the reliability of joining ceramic substrates with each other and a ceramic substrate with an LSI can be improved. |
