| 摘要 |
PROBLEM TO BE SOLVED: To reduce the warp of a printed wiring board having a cavity for housing an electronic component.SOLUTION: Since the thickness t1 of a first conductor layer 34S on the side of a first surface S is made thick, while the thicknesses t2, t3, t4, t5 of a second conductor layer 34F, conductor layers 58F, 159F, 258F on the side of a second surface F are made thin, the volume difference between the conductor layer (first conductor layer 34S) on the side of a first surface and the conductor layer (the second conductor layer 34F, and conductor layers 58F, 159F, 258F) is made small. As a result, the difference of coefficient of thermal expansion (CTE) between the conductor layer on the side of a first surface and the conductor layer on the side of a second surface is made small, thus suppressing warp of a printed wiring board.SELECTED DRAWING: Figure 1 |
