Really helpful PCB assembly methods overview from the talented Zach Hoeken Smith at Haxlr8r who has spent a few years in Shenzhen, China observing how the various factory machines work — taking videos such as the one above to document some of the more striking examples of what is possible. From his PCB Assembly 101:
Electronics are inside nearly every consumer hardware device you buy today. They are the brains and guts that make our devices interesting. If you’re building a hardware startup, chances are good that you’ll need to design and produce your own custom electronics. If you have an electrical engineer on your team, chances are they know how this process works. If not, then this guide is for you.
The home of Haxlr8r, Shenzhen, is sometimes called the Factory of the World, and for good reason. You can’t throw a rock without hitting an electronics factory. The goal of electronics assembly is simple: connect all of your components together using molten metal, copper foil, and some fiberglass+epoxy to hold it all together. Then it starts to get hard.