I am nearing the stage after testing everything on a breadboard where I'm ready to fire up Eagle CAD and start developing my circuit board. This will be my first ever circuit board design. My question now is: Should I design for through-hole or just go straight to surface-mount?
I have a pretty good soldering station (Weller WSM-1), so I think if I use reasonably large SMD components I should be able to hand-solder things with no problem. On the other hand, with through-hole components it would be impossible to not be able to solder them. The board is very basic, with just one ATtiny85, three resistors, a bunch of LEDs, two ceramic capacitors and a 32.768 kHz crystal. The crystal is another point I'm unsure of: Every electronic device I've opened up has these as hand-soldered through-hole, even if the rest of the board is all surface-mount. Why is that? Are 32.768 kHz crystals not available in surface-mount packages?
I would really appreciate any input on helping select the best way to go on the board design (through-hole vs surface-mount). I'm thinking that in the unlikely even that my board becomes popular, having it as an SMD board would facilitate production at a plant that can do automated assembly. On the other hand, I have no idea if through-hole manufacturing would be a cheaper option for certain quantities.
Best Answer
There's no reason to go with through hole. There, I said it.
With a decent microscope, a pair of soldering irons (to lift double sided components), hot air, solder paste and some flux you can easily solder components and modify things. I do 0201 on a daily basis with this setup. 0402, 0603 are no big deal. Also TSSOP, QFNs can be soldered (QFN with flux and hot air is pretty easy).
Through hole forces a completely different architecture for the board layout and the results of using a through hole design could differ, especially as it concerns EMI (think FCC certification). You want your board to resemble as close as possible the final product. Through hole requires space on both sides of the board for the holes and so wastes precious PCB area. Smaller PCB usually means lower emissions too (as well as lower costs etc).
BTW, this doesn't mean the whole design has to be surface mount. 32kHz crystals do come in SMD. There are plenty of them at digikey.
I realize this is an opinion but the reality is SMD isn't the terrible thing that its been made out to be, even for hobbyists.