Getting started with SMT soldering

[stern0m1]

I played around a bit, doesn't sound so complicated as it sounds.

Im wondering if there is a profile that could be used to use  reflow soldering to solder in plastic headers? I played around a bit with partial success, meaning the headers melted a bit but still usable. Im using a toaster on broil, so the heat is coming from on top. Im wondering if the plastic takes longer to melt, so If  the right speed and temp is figured maybe it can be done. My toaster takes a long time to heat up even though I wrapped it in insulation.

[jra]

Headers I would solder by hand.  Maybe a heat gun would work on headers if you want to use paste, I've never tried that particular technique but now you've got me curious.  The Hakko FX-888D perkey referred to is very nice and reasonable for $100.  I bought a Aoyue 968A hot air rework station specifically for the heat gun, believe it was around $175 at the time.  It is not as good as the Hakko but the least expensive Hakko heat gun I could find (FR810B-05) is currently going for $850 on Amazon and that was a bit much to justify on a hobby that I seem to have less and less time for.  I reflow using the hot plate/frying pan technique, very low tech but it's working for me.

[TomWS]

I also have another video that shows how I currently make stencils on my laser cutter, they don't last but they are great for prototypes:

Felix, I tried your Laser Engraving technique and, while I have some minor tweaking to do, the resulting stencil is certainly usable for 0.65mm pitch devices.  Thanks for the tip!

Tom

[Felix]

Great first try!
It takes me a few minutes to tweak the laser settings every time I etch stencils.
I have a ballpark of the speed, power and other settings like step size etc. Then I usually play with speed and power depending on the detail of the apertures.
Once I etch some sample pads to the quality I want I submit the complete job.
It can take a good 30 minutes for instance to etch a large panel stencil. I usually do this when I get a new design which I consider alpha stage and for a few application this will work just fine. Then I make stainless stencils when I feel the panels require no other changes.
So if I can do that, anyone can easily etch small stencils to very fine pitch/detail, just a little patience and practice is required.

[stern0m1]

For manual soldering standard headers what size solder should I be using?

Thanks

[TomWS]

For manual soldering standard headers what size solder should I be using?

Thanks

031 is a good all around solder.  Kester is a good brand.

[stern0m1]

Does this solder look good for general purpose solder for a newbie?
https://www.amazon.com/gp/product/B00068IJOU/ref=od_aui_detailpages00?ie=UTF8&psc=1

Thanks

[TomWS]

Does this solder look good for general purpose solder for a newbie?
https://www.amazon.com/gp/product/B00068IJOU/ref=od_aui_detailpages00?ie=UTF8&psc=1

Thanks

PERFECT!

[stern0m1]

Didn't realize originally, but that solder is leaded. I  rather not use leaded solder (due to health risks). I looked again and I cant find kester lead free solder reasonably priced. I found this solder on amazonhttps://www.amazon.com/gp/product/B01LSJ7FWW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 Mudder is the brand name. Have you ever heard of that name?

What other brands are "brand names"?

Thanks

[perky]

With reasonable ventilation in a room the risks of a hobbyist using leaded solder are very small IMO. The main danger doesn't actually appear to come from the lead either, it's the vapourized rosin. So rosin free, no-clean leaded solder is pretty safe. Remember lead free also melts at a higher temperature than leaded, which ironically can make things worse for rosin especially in a more confined space and will certainly make soldering more difficult.

https://diamondenv.wordpress.com/2011/01/06/lead-exposure-during-soldering/

Mark.

[stern0m1]

With reasonable ventilation in a room the risks of a hobbyist using leaded solder are very small IMO. The main danger doesn't actually appear to come from the lead either, it's the vapourized rosin. So rosin free, no-clean leaded solder is pretty safe. Remember lead free also melts at a higher temperature than leaded, which ironically can make things worse for rosin especially in a more confined space and will certainly make soldering more difficult.

https://diamondenv.wordpress.com/2011/01/06/lead-exposure-during-soldering/

Mark.

Very interesting!

[stern0m1]

I tried my first SMT reflow soldering... The solder came out  grayish dull, doing the reflow is was shiny metal. What does that mean?

Thanks

[stern0m1]

Looking at at a bare PCB how can one identify quality manufacturing vs poor? What are things to look for in regards to quality?

Thanks

[perky]

Several things I look for:

1 ) Drill registration. Look for the via holes being central to the via pad and hole.
2 ) Hole sizes are finished holes sizes, what you expect and accurately aligned.
2 ) Consistent etching. Look for good clean etch edges on traces and accurate widths.
3 ) Over-etching on corners. Check there are no over-etched corners or angles.
4 ) Uniform thickness of PCB and within expected tolerance.
5 ) Silk screen alignment. Check no silk screen on pads due to mis-alignment and is readable.
6 ) Reworking. Try removing and replacing components a few times to see if the heat reduces the glue strength for pads.
7 ) ATE tested PCBs. Order pre-tested PCBs, usually they use flying probes to check connectivity against the gerbers.
8 ) Wetting. Make sure the pads can accept solder easily.

Finally do a power-ground short test with a multimeter. Check each power supply signal on the PCB is not shorted to any other power supply signal or ground, the last thing you need after fully assembling a PCB is a power short because you'll have no idea whether it's a component or the PCB at fault.

Mark.