When you soldering components on PCB with hot air and microscope you have one big problem - its an angle of hot air gun. If hot air gun is not of 90 degrees angle to PCB, you will blow component, because of air pressure is on an angle to it.
All microscope lights I've seen on the market have a large outer diameter, so with those lights, you can't position hot air gun near 90 degrees angle to PCB. With my solution you may)
I used for this project parts from the inexpensive(1.5$) Chinese DC-DC converter, and 32 pcs 5050 LEDs.
It works from 2A PSU with micro-USB connector.
I use it with a NIKON SMZ-1 ESD stereo microscope.
Details
You can find the schematic, BOM ang GERBERs in the attachment.