| 摘要 |
PURPOSE:To realize the back wiring board with an excellent mount efficiency able to branch the bus at an optional point respect to the back wiring board having a branch bus branched without deteriorating the characteristic at a high frequency band. CONSTITUTION:In the back wiring board 10 comprising a shelf 30 accommodating a printed circuit board package 20 and a bus 11 made of a microstrip line arranged at the rear side of the shelf 30 and interconnecting the printed circuit board package 20, an impedance transformer 12 is provided to a branch point of the bus 11. |
