The main requirements for soldering with tin are time, space, calm, and good lighting, but it would be a grave mistake to ignore factors such as technique and tools. In fact, there are extraordinary resources that not only perform soldering that is nearly impossible for the human hand, but also reveal unique details that, normally, escape our eyes entirely. That brings us to the YouTube channel of Robert Feranec, who shared examples of BGA, TSSOP, QFN, and manual soldering under a Keyence VHX-7000N microscope.
Recently I discovered that my tin soldering sessions have become a miserable experience for a simple reason: I can't see anything up close. Belonging to the "40plus" generation and having spent more than a quarter of a century in front of a screen are details that start to take their toll, and there's nothing I can do beyond the obvious solutions.
Now, many online hobbyists have acquired microscopes to overcome these natural limitations, and at the same time, generate videos of their work. Personally, these devices are outside my budget, and I don't do soldering often enough to justify the investment (I already made that mistake before), but the professional space has access to truly magical tools, and one of them is the Keyence VHX-7000N microscope that Robert Feranec tested in recent days. Watch this:
Extreme close-up tin soldering, ft. Keyence VHX-7000N
The first example is based on BGA soldering, ball-grid-array. The microscope can change angle without losing focus at any moment, while also maintaining resolution and framerate. Robert also took the trouble to share an incorrect example, with a misaligned chip, no flux, and excess heat.
The next two cases are TSSOP (Thin Shrink Small Outline Package) and QFN (Quad-Flat No-Leads) packages. Both use solder paste, micro-spheres of tin suspended in flux, and one scene shows us a three-dimensional model of all the soldering. Excess paste can create unwanted bridges between pins, while in the QFN format, excess flux usually leaves the chip floating, without connection.
Obviously, soldering by hand with a microscope like this falls into the category of overkill, but it gives us an excellent opportunity to study the differences between traditional tin soldering and one using lead-free solder. Among the mistakes, we find two classic situations: too much tin, and too little tin.
To finish... I couldn't determine the official price of the Keyence VHX-7000N. Some sources mention 30,000 euros with a single lens, and as expected, on the manufacturer's page they only say "Contact us".
