| 摘要 |
PROBLEM TO BE SOLVED: To provide a means of improving signal output from a semiconductor chip to a printed wiring board in a flip chip/ball grid array assembly by repositioning signals passing through upper signal layers of a carrier from the chip. SOLUTION: This improvement achieved by signal repositioning involves fanning out, via a chip carrier, circuit lines from the top surface which communicates with a chip through the core to the bottom surface, where signals exit from the carrier to a printed wiring board. This fanning out is achieved by making better use of the surface area of the signal planes between the core and the chip. Signals are fanned out on each of the upper signal planes so that much more signals are transmitted through vias in the core to the bottom signal planes, where the signals can be taken out of the footprint area of the chip, thereby increasing the circuit density taken out of the footprint area. COPYRIGHT: (C)2005,JPO&NCIPI |
