In this video I show you a few tecniques for soldering SMD components. We start easy with two pins components of size 1206, 0805, 0603 and 0402. Then some SOT23 and some SOP8 and SOP16. We also solder microcontroller, QFN chip with soldering stencil and solder paste and the hot air gun.

https://www.solder.net/hand-soldering-services/

It’s said that the electronic devices we use on a daily basis, particularly cell phones, could be so much smaller than they are if only the humans they’re designed for weren’t so darn big and clumsy. That’s only part of the story — battery technology has a lot to do with overall device size — but it’s true that chips can be made a whole lot smaller than they are currently, and are starting to bump into the limit of being able to handle them without mechanical assistance.

Or perhaps not, if [mitxela]’s hand-soldering of a tiny ball-grid array chip is any guide. While soldering wires directly to a chip is certainly a practical skill and an impressive one at that, this at least dips its toe into the “just showing off” category.

The chip is an ATtiny20 in a WLCSP (wafer-level chip-scale package) that’s a mere 1.5 mm by 1.4 mm. The underside of the chip has twelve tiny solder balls in a staggered 4×6 array with 0.4 mm pitch. [mitxela] tackled the job of soldering this chip to a 2.54-mm pitch breakout board using individual strands from #30 AWG stranded wire and a regular soldering iron, with a little Kapton tape to hold the chip down.

Hand soldering a WLCSP package
https://www.youtube.com/watch?time_continue=225&v=edERx4x5eY0

For a DIY reflow setup, most people seem to rely on the trusty thrift store toaster oven as a platform to hack. But there’s something to be said for heating the PCB directly rather than heating the surrounding air, and for that one can cruise the yard sales looking for a hot plate to convert. But an electric wok as a reflow hotplate? Sure, why not?

Reflow Soldering Hotplate
http://www.instructables.com/id/Reflow-Soldering-Hotplate/

SMD Soldering – Hand Soldering – Small Packages : 0805, 0603, 0402, 0201, 01005

By 2016, most people have got the hang of doing SMD soldering in the garage–at least for standard packaging. Ball Grid Array or BGA, however, remains one of the more difficult packages to work with [Colin O’Flynn] has an excellent video (almost 30-minutes, including some parts that are sped up) that shows exactly how he does a board with BGA.

[Colin] uses some spare boards to lock the target board down to his bench and then uses a custom stencil and solder paste to prep the board. Once he has the solder paste on, he places the components using a homebrew air tweezer and some regular tweezers.

For reflow, [Colin] uses the common T-962A with the open source firmware. Two other modifications to the oven: a custom vent hood with a carbon filter and a Jolly Wrencher sticker for decoration (we heartily approve).

Complete PCB Hand Assembly (FPGA in BGA Package + reflow)
https://www.youtube.com/watch?v=-DMYJmB4naA

Given the right tools — including a digital microscope — it’s possible for anyone who is reasonable adept to hand-solder electronic systems based on surface-mount technology (SMT).

According to this ifixit column: “Jessa taught herself how to microsolder, fell in love with repairing electronics, and started a repair business called iPad Rehab in Mendon, New York. Now she does board-level repairs for a living and teaches microsoldering to other repair techs.”