What is material to be use for PCIe Gen 6.0/7.0?

Manufacturing Flex and rigid-flex
1

Hi Team,

what is material to be use for PCIe Gen6.0/7.0. ? Magtron, Rogers RO4835T, Isola Astra® MT77 will support in this case?

2 Likes
2

Hi,

For PCIe 6.0/7.0, choosing a very low-loss material is a necessity due to its very high speed requirements.

Out of the materials listed, Astra MT77 has the lowest Df (0.0017), then comes Rogers RO4835T(0.003-0.0035), and Df of megtron 6 is highest at 0.004.
So Astra MT77 is the best option among the three specified; you can also look at other Rogers materials like RO3003.

1 Like
3

can you walk through the calculation of how to determine what Df value you need, what other loss mechanisms are at play and how you work through the loss budget calculation based on the total loss allowed for a PCIE6/7 interface

1 Like
4

Hi,
To understand the loss mechanisms and a loss budget of the PCIe6/7 interface, one needs to read and understand that protocol. We are not experts in that protocol, so we cannot comment specifically about PCIe6/7.
However, typically speaking, two major loss factors are conductor loss and dielectric loss. Conductor loss depends on the profile of the copper that is used, and dielectric loss on the Df of the material used low Df means lower dielectric loss.

1 Like
5

Hi Pranav,

Thanks for your reply. can you update any stack up related to PCI 6/7
?

1 Like
6

We don’t have any stackups specific to PCIe6/7.
However, for the standard stackups, you can check out our stackup designer tool. It has many library stackups.
Based on different via requirements, we have HDI options as well which you can check out.

In that tool, just select the Material required, the number of layers, and you will get bunch of options. You can add impedances also in the stackup report.

1 Like