| 摘要 |
PURPOSE:To readily match the impedance of upward and downward wirings of high speed signal line wired to the side by forming a coplanar type transmission line with the high speed signal line, and grounding surfaces formed at the prescribed intervals on both sides of the signal line. CONSTITUTION:High speed signal lines for connecting an IC chip 7 provided above an IC package 1 with external terminals 211, 311 provided under the package 1 are wired at 212, 222 along the side of the package, grounding surfaces 412, 422, 433 are formed at the prescribed intervals on both sides of the wirings 212, 222, and the impedances of the upward and downward wirings of the signal lies are matched by the signal lines wired at the sides and the grounding surfaces formed on both sides of the signal lines, i.e., side wirings 412, 212, 422 and 422, 222, 432. |
