| 摘要 |
A wiring board (20) is provided with a second wiring part (15) integrated with a first wiring part (10) in a thickness direction, in addition to the first wiring part provided with a plurality of wiring layers (1) and a plurality of external connecting bumps (5). The thermal expansion coefficient of the second wiring part is permitted to be smaller than that of the first wiring part but equivalent to that of a semiconductor chip (30) mounted on the wiring board. Thus, inner stress due to the difference between the thermal expansion coefficient of the semiconductor chip and that of the wiring board can be suppressed, and reliability of a semiconductor device (50) wherein the semiconductor chip is mounted on the wiring board can be improved. In the wiring board, sizes of facing surfaces of the first wiring part and the second wiring part are permitted to be same. Thus, even when a plurality of the semiconductor chips are mounted on the wiring board to improve the performance of the semiconductor device, only the one second wiring part is required to be formed, and high performance can be attained at a low cost. |
