There's another way to do it. Here's a teardown of a classic Nokia "brick" phone.[1] That's designed for automated low-cost vertical assembly. The case provides the basic structure, and everything can be put into the case with a vertical push. There are no internal wires to connect. There are simple machines for that kind of assembly. Then everything gets squeezed together, and you have a hard block of an object that's hard to damage.
If you can design something which can be assembled in that simple way, high-volume manufacturing can be automated cheaply. Smartphones are not built from parts intended to be assembled in that way, but that's a decision based on cheap labor, not one that's inherent in smartphone design.
Design for assembly was more of a thing when manufacturing was in the US. The Macintosh IIci was designed for vertical assembly. Everything installed with a straight-down move. The power supply outputs were stakes that engaged clips on the motherboard. No internal wiring.
The trade-off of the current smartphone assembly process (many parts and many steps) is driven by numerous factors, including cheap labor. It also considers: incremental design improvement, testing, defects, supply chain, model differenciation, ...
"but that's a decision based on cheap labor, not one that's inherent in smartphone design"
This is the heart of the matter. The US has abandoned skills because cheap labor in Asia. An example from the story about dealing with touch screen tests: they're employing disposable workers to toy with pinch and zoom testing; something easily automated with a simple machine and image comparisons. How sad. This is an actual regression in technology.
If the US wants to get manufacturing back, the only areas that matter are electronics and, to a lesser extent, machinery. See this chart.[1] That's an achievable goal.
Here's a useful smartphone that could become big:
- Solid state battery that will last at least 5 years.
- 5 year full warranty.
- No connectors. Inductive charging only.
- Screen as unbreakable as possible.
- Sealed unit. No holes in case. Filled with inert gas at factory.
Then Tim Cook gave up on manufacturing. Which was how it saved Apple.
Steve Jobs always had a somewhat fantasise vision of dark factory. He wasn't able to accomplish that when Apple was still fighting for survival. But now Apple has more cash then it knows what to do with it.
a bit of the problem is that modern elements like display + touch screen require a lot more bandwidth than 3110 - for example the displays require ridiculous bandwidth in comparison to the nokia, like 10 gigabit/s for Samsung Galaxy S25 (basic model, not plus/ultra), plus connectors for the cameras.
At the very least you can't really make the screen soldered-on, and the simple connectors used in Nokia might not work out for such high bandwidth use case. Same with cameras.
Thin ribbon connectors are one of the hardest things to automate from what I remember regarding Sony's efforts to automate PS5 manufacture.
If you can design something which can be assembled in that simple way, high-volume manufacturing can be automated cheaply. Smartphones are not built from parts intended to be assembled in that way, but that's a decision based on cheap labor, not one that's inherent in smartphone design.
Design for assembly was more of a thing when manufacturing was in the US. The Macintosh IIci was designed for vertical assembly. Everything installed with a straight-down move. The power supply outputs were stakes that engaged clips on the motherboard. No internal wiring.
Then Apple gave up on US manufacturing.
[1] https://www.youtube.com/watch?v=7xglr0Zy8s8