When soldering is done by hand there are lots of aspects that factor into how fast it can be done. Here are the largest factors for me when I am soldering:
- The pitch of the components. I have this cover both IC pitch and 2-pin size. The smaller they are the slower the human has to go to get it set properly.
- Through Hole components or SMD or both. Through-hole components will actually take a lot more time to solder in my experience.
- How closely spaced the components are. Humans will always make mistakes and the closer the parts are together the harder it will be to fix them. Also the closer they are together the more likely a slip of the hand will cause another component to get hit and have to be fixed.
- How organized the parts and documents of assembly are. This one is pretty clear, if it is hard to figure what to put where it is going to take longer.
In general though, I would say it takes me about 45 seconds per part to place the parts on the board. The board can then be baking while more boards are assembled.
#PCB Assembly
