| 摘要 |
PURPOSE:To improve electric and thermal characteristics by mounting a wiring substrate, which has polyimide multilayer wiring, on a ceramic substrate where wiring is formed and I/O leads are attached to four sides, and connecting a plurality of ceramic packages of cavity-down methods to the wiring board with solder bumps. CONSTITUTION:A wiring board 3 is placed on a ceramic board 1 where leads 9 are attached to the four sides, and electrode wiring on the wiring board 3 and electrode wiring on the ceramic board 1 are connected by bonding wires 10. A heat-conductive block 5 for heat radiation is attached onto the ceramic board 1, and the heat-conductive block 5 is hollow for the part wherein a ceramic package 4 is mounted, and is arranged so that a copper piston 6 may slide. This piston 6 presses the ceramic package 4 against a copper tungsten plate 15 by means of a spring 12. Hereby, wiring length becomes short, and also needless floating capacity and inductance become small, so signal transmission delay time becomes small, and it can exhibit high speed performance. |
