| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact, thin, and highly reliable wiring board of a which can correspond to mounting of a semiconductor element of extremely high integration degree. SOLUTION: A via land 11a of a wiring layer 11 arranged in a first surface of a rigid first insulation layer 21, and a via land 14a of a wiring layer 14 arranged in a second surface of a flexible second insulation layer 22, are electrically and mechanically connected by a a third insulation layer 23 held between the first insulation layer 21 and the second insulation layer 22, and a conductive pillar which is arranged to connect the via land 11a and the via land 14a through the third insulation layer 23. |
