SMD prototyping and soldering

Support Schematics & PCBs
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Hey all,

I’m looking to get into some PCB design for some random projects and would like some input.

I understand that there are a few ways to solder up SMD components such as a hotplate and super steady hand with soldering iron and a fine tip.
For a beginner what would you guys recommend? I hope to use the new RP2040 chip that Pi foundation has released for some bonnets for the Pi and other random things.

PS: the factory videos have been really helpful seeing how stuff is made!!

Liam.

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I switched from through hole components to SMD about 5 years ago, there’s a bit to learn.

As you’ve most likely seen there are many ways to go, frying pan, toaster oven, hot air and soldering iron.

I started out with a hot air rework gun and that’s what I’d recommend.

Have a look on eBay or Aliexpress for a kit that includes the gun, tweezers and optic style magnifier for $50 or less. Mine is 75W, I see units rated at 800W but I’m sure that’s just BS.

I stick with 0805 (2012) size Rs and Cs and 50 mil SOICs where possible, 0.8mm pin spacing on big chips is the smallest I’ve used. These sizes are easy to handle and I’ve not had any problems.

The RP2040 chip has 0.40 mm pin spacing which might be a bit of a challenge for a first go. Not saying it can’t be done but I suspect it’s beyond the limit (or my limit) for manual placement.

I bought a couple of SMD practice kits to get some hands on experience before laying out my own boards.

Good luck, Ken.

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Hey Ken,

Thanks heaps for the response!!

Yeah 800 sounds like quite an exaggeration. I’ll definitely take a look around the net for some cheapers stuff.
If you don’t mind would you be able to share a bit about your project?

0805 will definitely be the starting point and I would say the first couple PCB’s will be through hole at least… before jumping into the deep end.
Many thanks!!

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I’ve got to agree with the hot air gun recommendation. I recently started using one for my pcb work and barely even touch my iron anymore. Get yourself some good flux and soldering paste and if you plan to do anything tiny, get a stencil made with your pcbs to make application of the solder paste as accurate as possible. Smallest I’ve done so far is some TQFN packages but I also use lots of 0603 passives and have no trouble doing them by hand (albeit with the air flow rate turned right down low on the hot air gun). I know there are people out there even doing some BGA style chips with a heat gun, although I imagine positioning on that would have to be much more critical. I’ve done 0.5mm spacing connectors by hand with an iron, so I’m certain a 0.4mm chip should be no trouble with a hot air gun.

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Hey all,

Excellent discussion!!

This is definitely a good pointer for those looking to get into SMD and getting into fixing parts (watch out for capacitors though!!)

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