From Hackaday:
The USB-C standard with its smaller connector has so far mostly escaped this trend, though this might be about to change thanks to the work of [Sam Ettinger]. His own description of his USB-C connector using a flexible PCB and a BGA-packaged ATTiny84A microcontroller is “cursed”, but we can’t decide whether or not it should also be called “genius”.
Key to this inspired piece of connector fabrication is the realization that the thickness of BGA and flex PCB together comes to the required 0.7 mm. The BGA provides the necessary stiffness, and though it’s a one-sided connector it fits the space perfectly. There are several demo boards as proofs-of-concept, and the whole lot can be found in a GitHub repository.
OSH Park 