Starting SMD fabrication - any pointers appreciated!

[BluffChill]

Hi all

I've got a moderately successful line of pedals which sell really well and I'm actually in a position to start producing them on a large scale, so I'm looking into SMD production for my next run as it's very difficult to keep up with orders.

I've been designing PCBs for a few years now so know my way around relatively complex (but still analog and through-hole) PCBs so it's not totally new to me. But I know there are a couple of different sizes when it comes to SMT, and wondered if there was one that is objectively used for pedal design? I think I have found a supplier I want to use too but am open to suggestions on anywhere to serves the UK/EU, too. And any resources or guides would be appreciated!

[merlinb]

If you want components that you can still handle easily with tweezers and a soldering iron, then you can't go wrong with ICs in the SOIC package, and resistors & ceramic capacitors in the 1206 package. The bread and butter of the SMD world. The 0603 package is also doable by hand, but more fiddly, obviously.
I've never bothered to try to handle SOP and BGA packages by hand. People do, but life's to short IMO. Same for 0402.

[cloudscapes]

0603-0805 is fine for pedals I think. small enough to be compact, and juuuust big enough to allow mods/fixes.

[Ripthorn]

I use 0805 and can solder them by hand just fine. I also use the SOIC packages, though TSSOP saves a little more space.

[BluffChill]

Thanks all for your advice on sizes - but I'm going to order these pre-populated so I don't have to do anything by hand!

[vigilante397]

If you're getting them suffed by a fabrication house instead of doing them by hand then definitely use whatever IC package is convenient and cost-effective, though for troubleshooting purposes (no fab house is perfect) I second what everyone else said about the hand-solderability of SOIC. For passives I would definitely recommend 0603 or larger (I solder all my boards in a reflow oven but stick with 0805 passives) again for debugging purposes, because 0603 is the smallest package that still usually has the resistor value printed on the package; 0402 and smaller are just blank, which can make finding a wrong value harder.

So hand-solderability isn't a huge deal from a fabrication perspective, but you should still keep debugging/repairability in mind.

[BluffChill]

Thanks - that's very helpful. I'll probably do a mix for some of the most tweaked values so I still have some degree of control for debugging.

[Ice-9]

Most fabrication houses will charge more for parts that are not on their standard component list, ie 1206 parts may cost more per value for a setup fee while 0805 or 0603 parts will be setup fee FREE. So I would advise submitting your design for cost and see what BOM pricing comes back with, for example I often use JLCPCB and if I design for 1206 passives it costs a heck of a lot more than if my PCB and BOM is submitted as 0805.

[BluffChill]

Thanks all for your help folks. Quick question though, for electrolytics, there doesn't seem to be an 0805 sort of option - KiCad just lists them in dimensions. Is there a preferred size?

[bartimaeus]

in smd you'll often see tantalum caps are used when small polar caps are needed, and you can find those in 0805 and 0605. i also personally prefer them to smd electrolytics because i find them easier to hand-solder.

[vigilante397]

I use 0805 caps for everything up to 10uF, 1206 for 22uF, and tantalums for 47uF and bigger. The only SMD electrolytics I use are 470uF.