| 摘要 |
PROBLEM TO BE SOLVED: To enable simple and effectively connection of semiconductor devices of intermediate or high performance with each other to a board, by separately forming one or more semicircular vias on the edges of the board, and using fine pitch ball grid array. SOLUTION: Individual units are formed, e.g. by separating a printed circuit board. A semicircular, i.e., half via 62 has an aperture 64 as a cylindrical section of an almost semicircular shape. In the semicircular via 62, a circular via 48 is separated into almost halves, and conductive material is arranged along a cylindrical section of a semicircular shape which is generated by cutting the circular via 48 in the longitudinal direction. The semicircular via 62 does not occupy usable space in a signal path forming region of the board. As a result, the space can be used for a chip and for signal path formation. Hence the amount of electrical connection between the top and the bottom of a board 42 is increased. |
