User:Rob Kam/sandbox1/Talk:SMT hand soldering

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Sn60 vs. Sn63: When is the use of one of these two alloys more appropriate than the other? The Sn60Pb40 has a plastic range and puts down a slightly thicker coating of solder. Sn60 is often preferred for lead tinning and other solder coating applications. Sn63Pb37 is eutectic and as such has no plastic range. Generally it flows better than the Sn60 and is the preferred alloy for wave soldering and surface mount applications.[1]

Which solder paste

There are all kinds of solder paste, where my experience led me: the ones in the jar are for stencils only, the balls are twice bigger and the paste is to thick to go through ( maybe very big ones). And you have the paste in a syringe which is more expensive but also has smaller balls so it is good for manual application with a syringe. Since these pastes need to be held cool and have limited shelf life of half a year i would not recommend ordering them from ebay but go to a local shop or webshop in your country. Btw the shelf life is for guaranteed production quality, for hobbyist i have it for over a year and still works fine[2]

The paste from a tub is for stencil use, not for syringe use. The lead balls are much bigger and stiffer then paste from a syringe (look under the microscope). [3]

  • Chip Quik No-Clean Sn63/Pb37
  • ArmackAmasan BF 32-3 Sn95Ag4Cu
  • loctite gc-10
  • Koki S3X58-M5O0C-7-500
  • Kester EP256 Solder Paste, No-Clean 63/37 - I have "pasted boards that sat around for three, four or five days before components got placed on them – no problem". I've had jars of the solder paste sitting around for months unrefrigerated that performs the same as brand new product. It has almost no residue, parts reflow and center perfectly on pads, I never have issues with tombstoning, and it has a great consistency that is great for either silkscreening or syringe dispensing.[4]
  • Loctite HF-2W

also


  • Practical Electronics - Components and Techniques by J. M. Hughes, O'Reilly, 2015, ISBN 9781449373078
  • [11]

preheat the PCB on a hotplate and reflow with hot air

what I do for 0603/0805 and SOT/SO parts:

1) apply solder (0.35 mm, lead free Felder ISOCORE, 3.5% flux, no clean) to one pad, or diagonal pads if a larger IC

2) pick part with tweezers, reheat the pad with the solder and place the part

3) solder the other pad(s)

4) done.

for smaller ICs like TSSOP I add some Edsyn FL22 flux to the pads, then solder them with the same 0.35 mm solder and tip as above, using a $200 stereo microscope (Amscope SE 400-Z, 10X) [12]

Tristana Twopointoh Thing is, I've never soldered SMD components before. Are the 0805 components involved reasonably large enough to attempt with a standard soldering iron? Alternatively, any suggestions for a hobbyist hot air gun? https://www.facebook.com/groups/174583056349286/permalink/356462168161373/ Facebook, 19 Dec 2017

-- Roger Salzgeber 0805 are huge. Just put a bit of solder on one pad, then place the resistor there, hold it down with a small screwdriver and heat the pad. repeat until it sits perfectly, then solder the other side. --

Ken Howard If you have never used one before it’s not a great idea to go the hot air way. Get a fine tip for your iron, or buy a new one that will take a fine tip, get some magnifying glasses, and use either the thinnest solder you can get or use solder paste from a syringe. The other absolute essential is a good pair of tweezers to place the parts and hold them in position while soldering. Take care and you won’t have too many problems with 0805 – you may even come to enjoy SMD more than through-hole assembly – I do

Tristana Twopointoh Luckily I already have an iron that has a very fine-tip to swap in, and some nice tweezers for picking and placing things. Is solder paste still a better idea for SMD over standard solder even when using an iron?

Ken Howard I very much prefer it. Place a dot of paste on each pad with a syringe. Place the part, hold in position with tweezers and apply iron to pads. I place all similar parts at the same time – if you don’t disturb them the paste sticks them down adequately for -- Mark Thomson A fine tip and 0.45 mm solder, some magnification and you are good! You can buy cheap SMD practice kits on eBay / Amazon which are ideal for getting used to it.....IMO SMD is easier than TH once you get used to it.

Tristana Twopointoh Where do I purchase the third hand to hold a magnifying glass in addition to the iron and tweezers?

Ken Howard Magnifying visor (eBay) is a good option. With 0805 you won’t need much magnification – even a pair of cheap +3 reading glasses will do a decent job

-- Jeff House The NLC modules were my first SMD experience and I've had no real problem using my standard iron. Go with the very fine solder, use a flux pen -- get a magnifying lamp if you can -- that made a huge difference for me. But the iron itself was just fine. Oh yeah, tweezers...definitely tweezers, and get used to using them in your off hand while soldering with your dominant hand, because you don't want to solder with your off hand.

Jamie Ferguson The worst bit (for me) about SMD resistor is getting the little fuckers out of the strips then having to try to flip them the right way over. Other than that, easier than through hold (though less fun for some reason).

Ken Howard The most important piece of advice is that if you accidentally drop a SMD resistor or capacitor on the floor, don’t pick it up! You will probably get the one you dropped yesterday instead

Jeff House Actually this is a really good point. At least resistors you can check (with a magnifying glass/loupe), but caps seem to be unmarked. I keep a 'clean area' on my work surface, if anything jumps out of the tweezers, or falls away, I just pick it up and throw it in the bin. These parts are cheap, better to remain 'sanitary' than risk infection

Phil McMillan Little chance of this – dropped 0603 caps disappear forever into the ether ...

Velleman VTLAMP10U Desk Lamp With Magnifying Glass – 12W – White Jeff House The magnification is perfect for me at least. It has a small lens-in-lens that's more like a 10x magnifier which is really good for reading the numbers on the back of SMD resistor packages. Some people find it annoying in their vision like that, but I'm used to it now. Sturdy enough, certainly, no issues for me (though I've only had it a couple months now). The only real complaint I have is that I work standing up and the angle it's at is a little weird for my use, so I end up putting it on a box. But that's not much of a complaint.

https://www.facebook.com/groups/synthdiy/permalink/10155297766846313/

  • It all comes down to what you Personally like. Using a hot iron is the most straightforward method. Ppl who wish to make a big batch would preffer making a stencil for the paste and use a hot plate. others will swear for the heatgun method. Anyway, Its best to start with the straightforward method and evolve from there. Just make sure youre using good solder and iron. https://www.facebook.com/groups/974453899290904/permalink/1773899876012965/

Solder balling

Reflist

  1. ^ FAQ | Kester
  2. ^ Solder paste, EEVBlog forum, October 2013
  3. ^ using solder paste out of a tub, EEVBlog forum, April 2014
  4. ^ Most appropriate solder paste for home/hobby use, EEVBlog forum, Jan 2018
  5. ^ Some solder paste to avoid, EEVBlog forum, January 2012
  6. ^ Solder Paste, EEVBlog forum, September 2012
  7. ^ good solder paste and flux pen, EEVBlog forum, October 2012
  8. ^ UK source of solder paste?, EEVBlog forum, December 2013
  9. ^ preferred Solder paste?, EEVBlog forum, January 2014
  10. ^ Solder paste recommendation, EEVBlog forum, January 2015
  11. ^ Solder Paste Recommendations., EEVBlog forum, September 2018
  12. ^ SMD soldering technique, Synth-DIY email list, March 2017
  13. ^ Are these balls because of soak or did I squirt too much paste? (reflow help)

Ref's

Images

Various links

  • Nuts And Volts 2009-01 p. 60
  • EPE 2019 02 p. 60 , 03 p. 60,
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