Frankfurt-based Maker and Twitter user timonsku decided to create his own carrier board for the Raspberry Pi Compute Module 4. He milled the PCB as a single copper layer with no vias or solder mask. He soldered it up, attached the CM4, provided power over USB-C and lo and behold, the screen sprang to life and displayed the OS he had loaded via a microSD card.
As he says on the Twitter thread, this wouldn’t pass any sort of certification, but the HDMI does work:
Here’s another pic showing just the carrier board:
This was just a proof-of-concept without any bells and whistles such as GPIO breakouts, but he did it just to show how relatively easy it is to do a simple carrier board for the CM4.
Thanks to Albert Hickey for spotting this!