Motherboard Stackup Recommendations - Intel 80331 Design Manual

Intel® 80331 I/O Processor Design Guide
Board Layout Guidelines
Table 5. Motherboard Stack Up, Stripline and Microstrip (Sheet 2 of 2)
Variable
Stripline
Microstrip
Trace Spacing (mil)
Stripline
Total Thickness (mil)
Microstrip
Trace Velocity (ps/in)
Stripline
Microstrip
Trace Impedance
(ohms)
Stripline
NOTE: Each interface sets the trace spacing based on its signal integrity of differential impedance
requirements. For the purposes of the building the transmission line models, it is assumed the artwork is
very accurate and therefore a constant. Thus, all the variability in the trace spacing is the result of the
tolerances of the trace width.
Figure 12.

Motherboard Stackup Recommendations

38
Nominal Minimum
Type
(mils) (mils)
4.0 2.5
15.0 -
12.0 -
FR4 62.0 56.0
- 135
167
50 42.5
50 45
M ic ro s tr ip
T r a c e S p a c in g
L 1
L 2 ( G N D )
L 3
L 4 ( V C C )
L 5 ( V C C )
L 6
T ra c e S p a c in g
Maximum
(mils)
5.5
- Each interface sets the trace spacing based on its
signal integrity of differential impedance
requirements. For the purposes of the building the
transmission line models, it is assumed the artwork
-
is very accurate and therefore a constant. Thus, all
the variability in the trace spacing is the result of the
tolerances of the trace width.
68.0
141
Velocity varies based on variation in Er. It cannot be
controlled during the fab process.
178
57.5
55
M ic ro s tr ip
M ic ro s tr ip T r a c e T h ic k n e s s
T r a c e W id th
L 1
L 3
L 6
L 7 (G N D )
L 8
S trip lin e
T ra c e W id th
S tr ip lin e
Notes
S o ld e r M a s k T h ic k n e s s
T ra c e H e ig h t 1
T ra c e H e ig h t 2
S tr ip lin e T ra c e T h ic k n e s s
T ra c e H e ig h t 3
C o re T h ic k n e s s
P la n e T h ic k n e s s
B 3 5 5 5 -0 1