Last week we had our first soldering workshop where two of our young members got to solder their own LED christmas tree decorations. The project took about an hour to complete. There were enough solder joints to complete to turn even a complete beginner into an experienced solderer!
We learned how much solder to apply to make the solder joints just right. Applying too much solder can short-circuit leads on the components whose solder pads are close together. Removing excess solder can be tricky unless you have the right equipment. Solder wick makes it easy to soak up the melted solder and fix short circuited solder pads.
We also learned that if we don’t heat up the solder long enough with the soldering iron then there is a risk that we get a so-called “cold joint” where the component is soldered to the printed circuit board (pcb). A cold joint might not conduct electricity as well as a properly soldered joint, it is unpredictable, and it might not last as well.
While avoiding cold joints by making sure we heat the solder up properly, it is also important to be careful not to apply too much heat to the component that we are soldering as if we do the components might break. This is especially true for some semiconductor components and transistors.
Holding the tip of the soldering iron so it meets the lead or pin of the component while also touching the solder pad for a couple of seconds, and then applying some solder to the area makes just the right solder joint. The whole process normally takes two to three seconds or so per solder joint.
Making these christmas LED decorations was a fun and rewarding way to learn a new skill. In the break we had fun stress testing our Pi Wars robot prototype and enjoying some early festive mini-cupcakes.
