Patent ID: 6489570
Filing Date: 2002-12-03
Classification: H05K

Abstract:
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 second ground wiring layer disposed between said third and fourth insulating substrates; a power wiring layer disposed between said fourth and fifth insulating substrates; a third signal wiring layer disposed between said fifth and sixth insulating substrates; a third ground wiring layer disposed between said sixth and seventh insulating substrates; and a fourth 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 7.5 mil; wherein each of said second and sixth insulating substrates has a thickness ranging from 3 to 13 mil; wherein each of said third and fifth insulating substrates has a thickness ranging from 3 to 15 mil; wherein said fourth insulating substrate has a thickness ranging from 2 to 6 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 and second ground wiring layers, said third signal wiring layer having a third resistance with respect to said third ground wiring layer and said power wiring layer, said fourth signal wiring layer having a fourth resistance with respect to said third ground wiring layer; and wherein said first, second, third and fourth resistances are within the range of 49.5 to 60.5 ohms.