User's Manual

Intel
®
820 Chipset Design Guide 5-5
System Manufacturing
5.3.9 Board Impedance/Stackup Summary
1. 7628 Cloth, 1 ply 0.007” when cured with 40% resin is the most popular and highest volume
PCB in production today. This stackup will make routing impossible.
•
Fab Construction (4 Layers)
•
Z
o
= 70 Ω ± 15%
2. 2116 Cloth, 1 ply 0.0045” when cured with 53% resin is the second largest volume in
production today. Due to the impedance & layout requirement of traces for Direct RDRAM,
AGP 2.0, and hub interface, this stackup is recommended for Intel
®
820 chipset platform
design.
•
Fab Construction (4 Layers)
•
Z
o
= 60 ohms ± 10%
Figure 5-3. 7 mil Stackup (Not Routable)
Total Thickness = 62 mils
Not Routable
Component Side Layer: 1/2 oz Cu
Ground Layer 2: 1 oz Cu
7 Mil Prepreg
Ground Layer 3: 1 oz Cu
Solder Side Layer 4: 1/2 oz Cu
7 Mil Prepreg
Figure 5-4. 4.5 mil Stackup
45iltk d
Total Thickness = 62 mils
~48 Mil Core
Component Side Layer: 1/2 oz Cu
Ground Layer 2: 1 oz Cu
4.5 Mil Prepreg
Ground Layer 3: 1 oz Cu
Solder Side Layer 4: 1/2 oz Cu
4.5 Mil Prepreg