| 摘要 |
PURPOSE:To enhance the density of mounting by increasing the thickness of a package of lower stage larger than that of a package of upper stage, eliminating improper electric characteristics by the thermal impact of a solder dip and reducing the entire semiconductor device. CONSTITUTION:The thickness t2 of a vessel of a semiconductor device 22 disposed at the lower stage of a semiconductor device in which a plurality of semiconductor devices are superposed in an elevational direction is formed larger than that t2 of a vessel of a semiconductor device 21 disposed at the upper stage. The relationship of the thickness between the upper stage and the lower stage is not limited to two, but similar in the structure that more than two are superposed. The lower stage is formed in the thickness durable against the heat, and that at the upper stage is reduced by that much. |
