[MechanicalTim]

Flexie circuit boards (commonly known as fpcs) have indeed been around for a long time. They are mostly used for interposer connctors and small components like LEDs, microphones, proximity sensors,small discretes etc. etc.

Based on the term "motherboard" used here I'm interpreting this to mean a bent/curved rigid circuit board which to my knowledge, is in fact novel. Obviously,the sections of the board containing the SoC and other chips will need to be flat, so I'm interested to see the utility here.

[justinclift]

> ... bent/curved rigid circuit board which to my knowledge, is in fact novel.

Yeah, it'll be interesting to see what they're actually doing.

Curved (in 3d space) circuit boards are certainly not novel in wearables though.

It's a very common design requirement to shape things to the human body area the device is being placed upon.

Thus people creating their own circuit boards using CNC on non-planar surfaces and similar. Saying that from having done it myself several years ago. There are also Youtube videos about this stuff as well.

[MechanicalTim]

I've never seen a curved rigid board and I'm having a hard time understanding how SMT would work. If you have examples I'd love to see them.

I've spent the last 15 years as a hardware design engineer in consumer electronics, 4 of those years were working on wrist worn wearables for one of the biggest players. Wearables utilize FPCs for curved sections. Sometimes sections the FPC will be stiffened with pieces of FR4 to support larger components, but the SoC, DDR, etc is always SMTd to flat rigid PCB. I've heard reports of rigid boards being bent if the stack up is only a few layers, but have never seen in a production product. Generally the traces and solder ball joints for the chips can't handle the strain.