DS320PR410: DELL/Foxconn WKS valencia MB DS320PR410 x2

Hi Robin,

Here is our feedback on the layout file:

• The devices are installed on the top layer of the PCB, however in the "past_top" layer I did not see the squares of solder paste under the device thermal pads that are recommended by the datasheet:
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  • See my E2E FAQ for more details: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1419809/faq-ds320pr810-how-should-redriver-thermal-vias-and-solder-paste-patterns-be-designed
  • If there is no solder paste underneath the device thermal pads, it is possible that the heat dissipation and GND connection could be suboptimal.
• This design has many PCIe signal transitions from the top layer to inner layers through vias. It is important to backdrill these vias, but I did not see them marked in the backdrill information:
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    • In this example picture (there are many other occurrences in the design), the transitions circled in red are from the top layer to L8, I did not see any backdrill marks at these vias in the "backdrill_bottom_l4" layer.
  • It is very important to backdrill all vias that transition from surface layers to inner layers, because otherwise there will be stubs that cause strong impedance mismatches, and therefore cause problems for signal quality.

Best,

Evan Su