| 摘要 |
PROBLEM TO BE SOLVED: To provide a printed circuit board in which the electrical connections are reliable between interlayer connections such as through hole and via hole. SOLUTION: Among various via holes for interlayer connections, a solder alloy is used to fill in a through hole (a first via hole) electrically connecting between the surface and the backside of a base board. In this structure, as the solder alloy filled in the first via hole is unitized with that of the conductive layer overhead, an interfacial delamination becomes difficult to occur even under harsh conditions with high temperature and high humidity as in a pressure cooker test. Thereby, a second via hole for another interlayer connection can be directly connected on the conducive layer with high reliability. |
