Also, even after ironing the surface will not be fully flat and some paste can end up in the space between the lines and go wasted.
A cheap low-power laser cutter is about the same price as a very cheap printer, which may be a better option if you can dial in the accuracy needed.
My PCB project's population time is currently 11 hours the last time I did it, from blank to tested, for one unit. The largest amount of time spent is on the resistors and capacitors - over 200 of them.
Getting a PCB mostly factory assembled for you is likely the better choice if you live in a building, as dropping hundreds of 100nF MLCC on a project can be brutal.
I guess the answer is yes one can do prototypes by hand if you take design considerations for pad access (sloppy mechanical tolerance for pencil/air rework), but probably one should be spending their time on design for lab EMC/EMI. =3
Robert Feranec does quite a few EE interviews, factory tours, and is generally accurate 97% of the time.
On the other hand, it gave me a great idea. What if you could 3D print the solder paste right onto the PCB using a tool that swaps out the hot end?
Also for 3D printing solder paste, this technique is called solder jet printing. But it isn’t very popular in the industry (despite being less wasteful) due to it being slower than stencil solder printing.
Good for large slow chip placement options, but community < 0402 feeder designs are still hit and miss. ymmv =3
The thickness of the stencil matters, because that determines how much solder paste you are laying down. This approach is going to produce thick stencils.
There are CNC machines for laying down solder paste. Here's one.[1] It does a few more jobs, too. The various CNC desktop board-making machines are still too expensive for most hobbyists, though.