An example PCB breakout design based on the C4072 package is provided to demonstrate good practices regarding BGA breakout optimization for crosstalk mitigation.
The PCB stackup and via construction used for the analysis are summarized as follows:
- 28-layer stackup with a total thickness of 131.9 mil
- Eight inner signal layers L3, L5, L7, L9, L20, L22, L24, and L26
- Via-in-pad
- EM890K PCB material (1035 × 1035) with HVLP copper foil for signal layers
Figure 1. 28-Layer Reference Stackup
Figure 2. Via Construction
