| 摘要 |
PROBLEM TO BE SOLVED: To reduce warpage of a board that may occur when mounting a semiconductor element and after that.SOLUTION: A wiring board (a package) 10 has a structure in which a plurality of wiring layers 11, 13, 15, 17 and 21 are laminated with insulating layers 12, 14, 16, 18 and 20 interposed therebetween and in which interlayer connection is made thorough via holes 13a, 15a, 17a and 21a formed in each insulating layer. A sheet-like member 30 is buried in an outermost insulating layer 20 located on the opposite side of a side on which a semiconductor element 41 is mounted, or in the neighborhood thereof, in the wiring board 10. The sheet-like member 30 has a modulus of elasticity and a coefficient of thermal expansion which are similar to those of the semiconductor element 41. The sheet-like member 30 is made of a material having a modulus of elasticity and a coefficient of thermal expansion which are enough to bring respective distributions of a modulus of elasticity and a coefficient of thermal expansion into a substantially symmetric form in a direction orthogonal to a board surface after the semiconductor element 41 is mounted. |
