| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring board which is equipped with a buildup layer laminated on the surface (one side) of its core board, capable of shortening a distance between a semiconductor element mounted on the front surface and an electronic part mounted on the rear surface or built in the core board, improving a conducting path between the semiconductor element and the electronic part in electrical properties, improved in mechanical strength as a whole, and hardly deflected or warped. SOLUTION: A wiring board 1 comprises a first core board 2 which is comparatively thin-walled and provided with a front surface 3 and a rear surface 4, a second core board 6 which is comparatively thick-walled and provided with through-holes 9 that form recessed parts 9 together with the first core board 2, and a buildup layer BU which is formed above the surface 3 of the first core board 2 comprising wiring layers 16 and 25 and insulating layers 23 and 26. |
