| 摘要 |
PROBLEM TO BE SOLVED: To provide a printed wiring board which makes it easy to position a via hole and can prevent a conductive material in the via hole from flowing out. SOLUTION: The printed wiring board has a via hole formed by laminating and joining insulating substrates 71 to 73 together, so that 1st buried via holes 61 and 63 and a 2nd buried via hole 62 are put one over the other. Further, the board has the 1st and 2nd buried via holes 61 to 63 formed by embedding a conductive material 56 in the via hole 57. On the sides of the surfaces of the 1st buried via holes 61 and 63 which face the 2nd buried via hole 61, an end of a conductive material 56 projects from the board surface and on the side of the surface of the 2nd buried via hole 61 which faces the 1st buried via holes 61 and 63, the end part of the conductive material 56 is hollowed below the substrate surface, and the diameter of the 1st buried via holes 61 and 63 is smaller than that of the 2nd buried via 62. |
