Patent ID: 6384340
Filing Date: 2002-05-07
Classification: H05K

Abstract:
A multi-layer circuit board comprising:first, second, third, fourth and fifth 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 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; and a fourth signal wiring layer disposed on one side of said fifth insulating substrate opposite to said fourth insulating substrate; wherein said first, second, third, fourth and fifth insulating substrates, said first, second, third and fourth signal wiring layers, said ground wiring layer and said power wiring layer are press-bonded to each other to form said circuit board with a thickness of about 1.2 mm; wherein each of said first and fifth insulating substrates has a thickness ranging from 4.175 to 4.725 mil; wherein each of said second and fourth insulating substrates has a thickness ranging from 5.7 to 6.3 mil; wherein said third insulating substrate has a thickness ranging from 15.2 to 16.8 mil; wherein said first signal wiring layer has a first resistance with respect to said ground wiring layer, said second signal wiring layer having a second resistance with respect to said ground wiring layer and said power wiring layer, said third signal wiring layer having a third resistance with respect to said ground wiring layer and said power wiring layer, said fourth signal wiring layer having a fourth resistance with respect to said power wiring layer; and wherein said first, second, third and fourth resistances are within the range of 49.5 to 60.5 ohms.