A Sample Of 12 Layers PCB Layout

Layer Stackup:                  Impeadance controll : 50 ohm (ADD, CRTL, DATA Bus, Clock, Antenna)

Layer   1 – Signal                                                  100 ohm (Ethernet TX/RX Differential Pair)

Layer   2 – Ground            Delay time tune : ADD_CTRL_CLK Group/ DATA (DRAM ByteLane)

Layer   3 – Signal                                                                                Max length wiring : 2500 mils

Layer   4 – Signal

Layer   5 – Ground

Layer   6 – Power

Layer   7 – Power

Layer   8 – Ground

Layer   9 – Signal

Layer 10 – Signal

Layer 11 – Ground

Layer 12 – Signal

LAYER 1 : TOP COMPONENT SIDE

LAYER 2/ 5/ 8/ 11: GROUND PLANE

LAYER 3: SIGNAL

LAYER 4: SIGNAL

LAYER 6 : POWER PLANE

LAYER 7: POWER PLANE

LAYER 9: SIGNAL

LAYER 10: SIGNAL

LAYER 12: BOTTOM COMPONENT SIDE

LAYER TOP + BOTTOM: COMPONENT SIDE

ALL POSITIVE LAYER:

SILK TOP:

SILK BOTTOM:

ASSY TOP (ASSEMBLY TOP):

ASSY B (ASSEMBLY BOTTOM)

DIFFERENTIAL PAIR 100OHM ANALYSIS OVERVIEW