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Is hand soldering a 48-VFQFN possible? I could not find any videos on this and I guess it must be quite hard.

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    \$\begingroup\$ I've met guys who with the right tools hand soldered BGA. YMMV. Is it possible? yes. \$\endgroup\$ – Hemal Chevli Jan 27 '18 at 10:29
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    \$\begingroup\$ From my perspective the most hard part of hand soldering will be ensuring exposed pad is soldered properly. \$\endgroup\$ – Anonymous Jan 27 '18 at 10:35
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    \$\begingroup\$ I've done it before. I have a soldering tip that I've ground a small cup on one side. This sops up excess solder when you run down the pins. Reflow is another way. Watch some videos. \$\endgroup\$ – lakeweb Jan 27 '18 at 17:12
  • \$\begingroup\$ Your best bet is to buy an affordable hot air rework tool. And maybe a hands-free magnifier that you can wear on your head so you can see (unless you have excellent close-up vision). It requires practice, but it can be done with hot air once you get the hang of it. \$\endgroup\$ – mkeith Jan 27 '18 at 17:39
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It 's possible by hand when you're very experienced with fine hand soldering, but for lesser souls it's also possible with solder paste and manual reflow with a hot air (rework) station.

With reflow, the part will align itself and solder will 'suck' towards the pins and pads.

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Yes, I have done it. I use a lot of flux for delicate solder jobs and to check the pad alignment I have a small USB microscope so I can check all sides without having to move the PCB.

I put a tiny bit of solder on one pad. Then a bit more flux and last the chip on top. Check with the USB camera and push the chip so all pads are aligned. Then I only have to heat the solder and not mess with a soldering iron AND solder wire.

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It's quite possible to reflow QFNs (even those with a big thermal pad) without any special tools or materials: Just a soldering iron, solder wire, flux, and a kitchen stove.

  • Tin the pads with a layer of solder of consistent thickness.
  • Apply flux and align the chip
  • Place the assembly on an old frying pan or directly on a hot plate, and crank up the heat until the solder melts and the surface tension pulls the chip into position.
  • Remove the board and let cool to room temp.

Obviously this only works with boards that only have components on one side. I wouldn't use this for any production boards, but IMO the results are still better than a hand soldering attempt.

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Hand soldering QFN chips is difficult, but can be done with fine solder and a small tipped iron. The standard footprint (intended for paste) needs the pads to be extended.

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