Patent ID: RE40068

Claim:
A multi-layer circuit board comprising: first, second, third, fourth, fifth, sixth and seventh insulating substrates disposed sequentially one above the other; a first signal wiring layer disposed on one side of said first insulating substrate opposite to said second insulating substrate; a first ground wiring layer disposed between said first and second insulating substrates; a second signal wiring layer disposed between said second and third insulating substrates; a third signal wiring layer disposed between said third and fourth insulating substrates; a power wiring layer disposed between said fourth and fifth insulating substrates; a fourth signal wiring layer disposed between said fifth and sixth insulating substrates; a second ground wiring layer disposed between said sixth and seventh insulating substrates; and a fifth signal wiring layer disposed on one side of said seventh insulating substrate opposite to said sixth insulating substrate; wherein each of said first and seventh insulating substrates has a thickness ranging from 2.5 to 6.5 mil; wherein each of said second, fourth and sixth insulating substrates has a thickness ranging from 3 to 9 mil; wherein each of said third and fifth insulating substrates has a thickness ranging from 3 to 23 mil; wherein said first signal wiring layer has a first resistance with respect to said first ground wiring layer, said second signal wiring layer having a second resistance with respect to said first ground wiring layer and said power wiring layer, said third signal wiring layer having a third resistance with respect to said first ground wiring layer and said power wiring layer, said fourth signal wiring layer having a fourth resistance with respect to said second ground wiring layer and said power wiring layer, said fifth signal wiring layer having a fifth resistance with respect to said second ground wiring layer; and wherein said first, second, third, fourth and fifth resistances are within the range of 49.5 to 60.5 ohms.