| 摘要 |
PROBLEM TO BE SOLVED: To provide a printed wiring board having improved rigidity by enabling connection between wiring layers via an insulating layer (or core material) containing a plurality of sheet-like reinforcing materials such as glass cloths. SOLUTION: The insulating plate-like first core material 1 having a first wiring layer 29 on one surface, and a second wiring layer 18 on the other surface is stuck on the plate-like second core material 1, having insulating performance and a third wiring layer 8 on one surface and a fourth wiring layer 27 on the other surface via the insulating layer 23, so that the second and third wiring layers face with each other. The first and second wiring layers are electrically connected to each other via a first via 14 piercing through the first core material, the second and third wiring layers are electrically connected to each other via bumps 21 piercing through the insulating layer and having conductivity, and the third and fourth wiring layers are electrically connected to each other via a second via 4 piercing through the second core material. COPYRIGHT: (C)2008,JPO&INPIT |
