@mmu_man @gsuberland
Wow! It seems that it could help developements for USB4 supports on FreeBSD (not by me).
https://wiki.freebsd.org/MohammadNoureldin/FreeBSDUSB4TBT3Support

This page was introduced at freebsd-hackers ML.
https://lists.freebsd.org/archives/freebsd-hackers/2024-December/004102.html

And a developer told me that insufficient supports for USB-PD controller could cause non-working Titan Ridge TB3 controller (my guess is that TB3 is now incorporated into USB4 spec) with the codes below off-list (so not disclosing his name here).
https://github.com/hselasky/usb4

The hardware design is now released at https://gitlab.com/dos1/debubo

Took me 3 days of soldering, but it works!

I can connect it to a Librem 5 and it automatically does all the needed PD stuff to expose its UART over USB-C It's also capable of a lot of other PD magic as a USB PD analyzer / injector / filter.

However, while these solder joints made a good job lasting till I got the firmware PoC working, it doesn't seem like they're going to last much longer... More soldering ahead

After a final test of the electronics, everything can be put together.
@techbeard drilled and countersunk the necessary holes in the aluminum extrusion and fabricated some corner pieces, so the back plate can be screwed to the extrusion.
We mounted the rails, backplane and #usbPD module array inside the extrusion. Now the PSUs can be slotted in, which is quite satisfying.

The housing of the #PDBrick is a piece of rectangular aluminum extrusion.
For mounting the server PSUs I decided to design and 3D-print some plastic rails, so the PSUs can be slotted in.
The DIY PSU backplane will get fixed to the front rails too, so the alignment and mechanical forces of the PSUs being slotted in will be manageable.

During final assembly of the array, the 100W module group suddenly showed a short circuit on the input.
I was puzzled at first, but had a hunch.
And sure enough, the 1mm thermal pad was slightly too thin and the main input ceramic capacitor punched through the thermal pad and shorted out against the aluminum strip.
Luckily it didn't crack ^^"
I fixed it by simply putting another layer of thermal pad on top :D

The 65W modules got tested too.
They stay surprisingly cool. After some time at full load it only reached around 50°C.

And it looks like the thermal solutions works exactly like intended.
As you can see in the thermal video, the modules beside the loaded one heat up noticably too (in comparison to the rows below, which you basically can't see at all, thermally)

After mounting the 100W modules to an aluminum strip, it was time to test the array.
We didn't have enough 100W capable loads to do a long full-load test, but close enough :D
The thermals look promising. The aluminum strip spreads the heat pretty well and got to around 60°C itself.
The hottest spot on the modules is now the USB port interlock P-FET at 90°C. And that will improve with airflow too.

During soldering of the 65W modules, I noticed that our heat sink concept worked almost too well xD
It was _really_ hard to solder to the power pads of the modules. Even if you heated it with a good soldering iron for over a minute, the other side of the solder joint was barely liquid.
As soon as you took the iron away, the solder solidified instantly.
And the enamel of the copper wire had to burn off too under those conditions, making it even more difficult.

Next, the modules are mechanically assembled into an array.
Four rows of five 65W modules are screwed onto aluminum strips with thermal pads in between.
These strips are then inserted into two 3D-printed side rails, which are then screwed to the front panel.

This is also the thermal solution. Because it should almost never happen that all modules of a row are fully utilized, the heat should spread and thus get carried away by the airflow better.

@techbeard milled the two front plates from copper clad FR-4 PCB material.
They feature a bunch of vent slits, so the server PSUs draw in air through/over the PD modules and cool them.

I ordered a handful of either module and tested them thoroughly.
Both support all relevant #usbPD profiles including PPS and a bunch of other fast charge protocols.
Thermally they behave pretty good aswell. Both #thermal pictures were taken after about 15min of 24V input and 60/95W load in open air.
The hottest component of the 100W module is the 5A SMD fuse with over 100°C :D
But our planned thermal solution should improve things a lot ^^