wonkothesane

It is not about: can it be done. Rather, it is about: can it be done such that it is sufficiently reliable and at the same time cost effective. 

It’s simply a difference between tightening 10 screws or ten million ones. 

We don’t talk about pick and place machines, or dispensing flux:solder paste. 

We talk very specific processes that imply specific challenges. 

Now, specifically tightening  on that scale and in this dimensions is this a challenge. Drilling “not so tiny screws” is a very standard process in Industry. And usually the correct amount of tightening is measured through monitoring of torque and/or angle. This works well when the inner resistance of the screwing part in that robot is significantly smaller than what you want to measure -and- the inevitable variation in geometry of the threads as well do not matter compared to what you need to observe in order to monitor your process. With tiny screws as used in the assembly of iPhones etc. this is not state of the art, meaning you can’t buy it off the shelf. 

There are similar challenges when dispensing glue in that tiny amount as required here. Stuff you do easily when doing this - some skill provided - by hand (such as compensating for change of viscosity based on small variations in ambient temperature, or material age, are sometimes surprisingly hard to implement automatically. 

It is also no big deal to drill a hole. Drilling 10 thousands in an airplane section, however, is. 

An experienced machine operator will easily tell you whether the cutting process is running well by simply listening to it. Decades of research have gone into automating this. So far, with very limited success. 

I am even not surprised about the issues with the ja fling of parts. While it sounds ridiculously easy to move a part from one station to another , the devil is again in the details. Takt time variations can be one, for example, reliably scanning parts, controlled acceleration and deceleration. All depending on the masses you want to move, and of course the required speed. If you go to major companies in automotive or aerospace you will find that handling is very often reduced to the max, or completely eliminated - due to cost and reliability. 

In all this one has also to consider that one big difference in the consumer electronic industry is that products are in do parison manufactured for a quite short time before a new model comes. This means, that there is simply also much less time for straitening out and issues before the new model arrives. 

All in all, I am sure that the major subassembly steps, such as making a PCB, are fully automated. It is the more “manual” processes that mount the sub assemblies together (such as screwing or glueing, welding...) are a challenge on that dimensional and production volume scale.