I will show you how to bonding a LED diode manually, soldering an LED directly.
Step 1: Get the LED
In this case I used a white LED SMD. Inside it has a blue LED diode covered with a yellow resin, It contains elements that make the blue light to appear white.
Step 2: Getting the LED (part 1)
For this work we need a microscope, also we will fix the LED on a PCB. Then we cut off the encapsulated.
Step 3: Getting the LED (part 2)
With a sharp object we remove the resin being careful not to damage the LED diode (the gold wire is not necesary, only the pads on the LED).
Step 4: Tinning the LED Pads
For tinning the pads we need small particles of welding wire. We get them scraping with a cutter. Then, we place a particle on the pad and approached the tip of the soldering iron. The heat will melt the particle on the pad. We do the same on the other pad.
Step 5: Bonding the Wires
We get the microwire from some coil, I get the coil of an old analog clock. We weld the microwire with the tip of the soldering iron. And we weld the microwire on the pads approaching the tip of the soldering iron. Finally we remove the LED from the PCB pressing carefully with a cutter.
Step 6: Using Your New LED
Now, because the LED and wires are very small, it is necessary to weld it on some base. This way you can manipulate easily.
Step 7: In a Joule Thief Circuit
I had the idea to set my LED on joule thief circuit. I used a 1.5v battery, a push button and the lens of a laser to see the LED. This is the result.