[SI-LIST] Help for PCB stackup!

Every body

I get a problem for PCB stackup, and I can't make the successful =
stackup.

The original PCB stack data follows as below

Layer   Material Type   Dielectric Thickness    Trace Width     Finished Cu
thickness       Dielectric Constant     Impedance (Ohm) Description=09
1       Conductive              7       1.60            50      Component
Side=09
        Dielectric      4.50
4.2             Core/Pre-preg=09
2       Conductive                      0.70                    GND
Plane=09
        Dielectric      8.40
4.2             Core/Pre-preg=09
3       Conductive              5       0.70            56 (Unpopulated)
Rambus Layer=09
        Dielectric      7.00
4.2             Core/Pre-preg=09
4       Conductive                      0.70                    Vcc
Plane=09
        Dielectric      5.00
4.2             Core/Pre-preg=09
5       Conductive              5       0.70            50      Signal
Layer=09
        Dielectric      4.00
4.2             Core/Pre-preg=09
6       Conductive              5       0.70            50      Signal
Layer=09
        Dielectric      5.00
4.2             Core/Pre-preg=09
7       Conductive                      0.70                    Vcc
Plane=09
        Dielectric      7.00
4.2             Core/Pre-preg=09
8       Conductive              5       0.70            56 (Unpopulated)
Rambus Layer=09
        Dielectric      8.40
4.2             Core/Pre-preg=09
9       Conductive                      0.70                    GND
Plane=09
        Dielectric      4.50
4.2             Core/Pre-preg=09
10      Conductive              7       1.60            50      Solder
Side=09

Dielectronic thickness, trace width and finished Cu thickness unit are =
mile.


Now I want to change the stackup to follow the conditions as below:

a)  Layer 3 and Layer 8 don't change, because RAMBUS signals in those
layers.
b)  The PCB's thickness doesn't modify. The total thickness is 1.6mm =
=A1=D310%
(62.4mil =A1=D310%).
c)  I have to rout traces impedance for 75 ohm in any layer except =
layer 3
and layer 8.

Does any one know the solution?



Best regards
Kent Wu

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