| 摘要 |
PROBLEM TO BE SOLVED: To provide a core board with fine-pitch connection between upper and lower sides, its manufacturing method, and a multi-layer printed circuit board. SOLUTION: A resist 12 with an opening 12a is formed (step B), and a plating step is carried out for the opening 12a to form a conductive pole 14 as a through hole (step C). The conductive pole 14 is hardened with resin 16 (step E). Since the opening 12a formed in the resist 12 can be made smaller than a hole drilled in a through-hole formation step, the fine-pitch connection between the upper and lower sides can be formed by using the conductive pole 14 formed in the opening 12a with a small diameter. |
