I will be designing an Arduino shield in KiCAD.
This will be my first project in KiCAD.
Considering I am a newbie in PCB design and I will be performing the soldering, what is the correct package size to pick?
The ones offered by the website I will be buying from are:
These package names are based on dimensions; 0402 is 0.04 by 0.02 inches, for instance. As a general rule of thumb, 1206 and bigger are easy to hand-solder, 0805 takes a steady hand but a bit of practice will have you doing them easily, and 0603 takes some real precision. anything smaller, I'd just give up trying.
The extra cost of 1206 is probably insignificant if you’re only using a few devices at a few cents each. Have a look at one and see how you feel about soldering it. 0805 is fine for hand soldering, 0603 requires a bit of skill. 0402 is awkward even if you’re quite expert. So I’d suggest using larger parts unless you’re desperately poor or very short on space. But certainly make the pads big enough that you can put the component where you want it and still touch the pad with your soldering iron.
My suggestion? Buy some of each size and some prototyping adaptors to practice on. This will give you a feel for the skills involved.
You may find that 0402 (1005 metric) isn’t too bad if your hands are steady and you have decent equipment. Or, you may find that you will need to make the investment in good soldering irons (get two - makes it easier to unsolder a part) and tips.
As it is, most boards are made with 0402 now as the go-to size, with larger sizes used for bigger / higher power values as needed. 0201 (0603 metric) and 01005 are almost beyond what can be done by hand for most people, but show up in compact boards like mobile handsets and other small electronics.
For less-skilled beginners and folks with poor vision or shaky hands, 1206 (3216 metric) and 805 (2012 metric) are a bit easier.
But... bear in mind also that if you’re considering SMT passives, you’ll probably be dealing with SMT ICs as well. There’s different types to consider.
0805 is a balance between size and cost. I use 0603 because considerably cheaper than 0805 but still manageable. 1206 is good and visible but expensive. 0402 is not advised.
It depends on your soldering technique...
If you're using solder wire (I recommend 0.25mm) it's easy to solder 1206, 0805 takes several solder attempts to get handy with, 0603 is still possible, but for most cases it's best to have microscope, 0402 is doable, but insanely hard.
If you're using paste, then I'd go for 0603 as default, because it's quite easy to solder it using pan/sand or oven technique.
So in general: buy one of those SMD kits that are used to learn soldering and try to do it. Most of it will have various size components. Like this one.
And I recommend to swap to paste as soon as possible, it's way easier (if you have proper tools). Benefit of paste is that you can solder whole board at once :)
