I would highly recoomend buying a used Vision Engineering Mantis (generation 1) device if you can get one for a reasonable price. It's a stereo device in opposite to the USB camera microscopes. 4x and 8x lenses are a good choice for working on electronic devices. It has become quite rare in the meantime, so it is pricy. But usually you'll buy such a device once in your life. Be aware to buy one in good condition if you are looking for one because there are no spare parts from the manufacturer available any more. If you don't destroy it by dropping etc., it will survive many major updates of Microsoft Windows...
If you can afford, you will not regret buying it.
If you need further spare parts availablity, you may also buy a generation 2 or a generation 3 device - of course, they're much more expensive.
Because of the working distance, 4x lens is recommended for soldering, etc. and 8x lens is recommended for inspecting. There is also a 6x SWLD lens available, but this is very rare for the generation 1 devices and extremely expensive if you can get one. For the newer devices, the 6x SWLD is still available in new condition for over €1000 (just the lens).
e.g.:
Ebay