In one of the recent live video broadcasts from Adafruit, Limor shows off some incredibly close views of the RGB LED packages they use, commonly called neopixels. Most of us vaguely recognize the pattern on the “pixel” but haven’t had the opportunity for this close of a view. One thing that stands out are the tiny wires that connect the individual parts of the neopixel. These itty bitty things are used inside of many parts that we never get to see and the process of putting them in place is called wire bonding.
Limor wondered out loud how wire bonding is actually, well, bonded and mentions off-hand that she’d like to see the process. Since I was merely watching and not having to continue hosting a live broadcast like Limor, I immediately started looking for videos.
It turns out that wire bonding is pretty cool to watch. I was quick to assume that these machines cost tens of thousands of dollars to start, but a quick search turns out that you can get your hands on one for between $200-$10,000 on eBay right now.
The bond itself isn’t just a simple solder. The principle they use is thermosonic bonding, which involves heat, high frequency vibration, and pressure.
One thing that stands out to me is the ability of the machine to form the wires as well as attach them. In the video below you can see the nozzle being pulled in a couple directions to form the perfect bends before it is bonded on the end.