Printed wiring board and method for manufacturing the same

摘要

A wiring board having a penetrating hole formed by forming holes with different shapes from both surfaces of a substrate. In such a penetrating hole, the depth of a first opening portion formed in the first-surface side of the substrate is shallower than the depth of a second opening portion formed in the second-surface side, and the diameter of a first opening is greater than the diameter of a second opening. Even if the gravity line of the first opening portion and the gravity line of the second opening portion are shifted from each other, the region of the second opening portion inserted into the inner space of the first opening portion may be made larger.