You have seen the micro components on the latest electronic devices. They are hard to see with the naked eye let alone hand solder them. It is more like watch making than making electronics. I discuss my adventures in hand soldering and end with a William Blake quote at Solder Wicki. And no. That is not a misspelling.
My Adventures In Soldering
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11 responses to “My Adventures In Soldering”
Broke down and bought a SMD hot air soldering station to assemble intermittent quantities of R&D PCBs. $80 on Amazon, made in China. Applying solder paste using a small syringe with the appropriate applicator tip, I can build/rework surface mount boards all day long, and fast. What’s nice is that the components don’t have to be perfectly square to the pads; when the hot air flows the paste the components self-align. Very few solder bridges even on fine pitch leads.
I’m hoping to earn enough some day to be able to afford such a rig.
What brand was it?
Ditto on the hot-air station, though I bought a used Hakko at a swap meet. I’ve heard that cheap little hot-air guns sold for desoldering work OK for SMT soldering… and then there are the toaster-oven and skillet methods.
I goober the pads and vicinity with what looks like a suitable amount of solder paste, plunk on the components, and commence application of hot air… then, usually, come back with flux-soaked solder-wick to clean up assorted bridges.
This works reasonably well even for fiddly 0.5mm pitch QFN parts, though getting the footprint right is important, lest the part float out of alignment with the pads. On a recent gadget, I found that the published footprints for a couple of tiny filters were too wide, and really needed the outboard ends of the pads brought in for reliable surface-tension centering.
It is actually possible to hand-solder 0402 parts, with a really pointy iron (e.g., low-end Hakko and the pointiest available tip) and sharp tweezers. Haven’t had occasion to try that with 0201s yet, but the day is surely coming (and my eyes aren’t what they used to be).
Hot-air soldering gives a much nicer finished look than poking at SMT pads with an iron; this matters if I’m reworking a client’s board, or planning to use one of my prototypes for show & tell.
Eric,
Thanks for that. I may have to change my methods. BTW for clean up after soldering I just swipe the flux pen across the joints of interest and give them a touch with the iron.
I think the brand on the one I got on ebay is W.E.P. (model # 852D+) but the identical station sold on Amazon is branded Kendal. I’ve installed down to 0.65mm lead spacing, nothing smaller. Getting the right amount of paste on the pads seems to be the key for flowing small-pitch components without bridging. I use a 0.020″ ID tip on the syringe, and even that’s a bit large for finer pitched components.
All my attempts at soldering have ended in failure, and sometimes burns.
CR,
Thanks!
I’m with John S. – but I assure you that I didn’t even consider misspelling till you mentioned it. I DO know the difference between soldiering and soldering. (Though I suspect a soldering gun would make a decent close-up weapon – probably better than most knives…electric-on or some really hot coals in the area being assumed.)
I got a W.E.P. re-work station, as well, and it works a treat. However, I used an ancient electric skillet for the hot-plate method (from my mother-in-law, the new ones have hot spots), and that is much nicer if you can afford to have a solder stencil made. These guys worked out well for me:
http://pcbstencils.com/
I also shelled out for a binocular microscope off of ebay, which came in very handy. I debated that purchase until I realized that I’d never seen a good tech lab without one. If you don’t have one you’re liable to have insuperable problems with solder bridging, especially the first few times through the process.
Good luck, Simon.
Kathy,
The word I was referring to was “wicki”. The normal way to spell that is “wiki”.
It is a play on words if you know soldering.
Look up “solder wick” to get it.
Neil,
I’m fine with anything down to .65 pad spacing. Not too limiting for now. I have saved your comment for future reference.