| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring board where a conductor layer is embedded in an insulating layer, with only the top surface of the conductor layer being exposed outside, and to provide its manufacturing method. SOLUTION: A three-layered pasted single-sided board composed of a resin layer 11, a very thin Cu layer 12, an Ni-release layer 13, and a 35μm thick Cu layer 14 of which are adjacent to each other is prepared. The outermost Cu layer 14 of the three-layered pasted single-sided board 1 is processed into a patterned conductor layer 14. Then, conductive bumps 21 are formed on the conductor layer 14, and furthermore, a prepreg 22 is superposed on the bumps 21 for the formation of an insulation layer 22 pierced by the bumps 21. Then, a wiring board 3 equipped with conductor layers each being located on its surfaces is arranged on the insulating layer 22, so that a four-layered wiring board 4 where interlayer connection is made through the bumps 21 can be formed. Then, the outermost resin layer 11 of the four-layered wiring board 4 and the very thin Cu layer 12 adjacent to the resin layer 11 are separated and removed from the four-layered wiring board 4. Lastly, the outermost Ni- release layer 13 of the four-layered wiring board 6 is removed. |
