Soldering is a necessary skill for any electronics work. Soldering is the process of using a molten conductive alloy, usually a combination of lead and tin, to join two metal parts. It can be tricky at first, but with a little practice you can learn to solder quickly and efficiently. However, soldering needs to be done correctly or it won't work. Poorly soldered joints can fail to conduct properly, ruining your project. Practice soldering with a scrap printed circuit board so that you don't have to worry about making mistakes.
Instructions
1 Plug in the soldering iron and set on its stand while it heats up. Give it some time; don't solder with an iron that isn't fully heated.
2 Coat the tip completely in solder. Rotate the tip and apply solder until all of the tip is covered. This is called "tinning" the iron, and it will help the iron transfer heat.
3 Wipe the tip on a damp sponge to clean it, then set the iron back in its stand.
4 Bend down the component's wire leads and insert them into their holes in the circuit board (also called the "PCB.") The top of the board is usually marked with the name of the part and the orientation of the leads if the part is polarized. Fit the component so that it is flush to the board.
5 Bend the leads at about 45 degree angles so that the component stays in place. Flip the board over so that the side with the contact pads is facing up.
6 Apply a tiny bit of solder to the tip of the iron. This will help the iron transfer heat, and help the solder flow.
7 Touch the tip of the iron to both the lead and pad. The solder won't adhere properly unless both the pad and wire are hot when you apply it. Let the components heat up for a second or two before you apply the solder. Avoid heating components for too long, as you may destroy sensitive components like semiconductors or even strip the pad from the board.
8 Apply solder to the pad. The solder will melt and flow around the pad and wire. Stop adding solder when the pad is completely covered. Remove the iron as soon as you stop adding solder. When the solder melts it will smoke. Don't worry, this is normal. The smoke is the rosin flux burning off.
9 Let the joint sit for a few seconds while it cools. If you move the joint it won't cool correctly. A properly soldered joint should be shiny and smooth when it cools. If the joint is gray or grainy looking, it's "cold" and won't work properly. If the solder balls up rather than flows over the pad, the pad was too cool and the solder won't adhere to it.
10 Solder the other wire lead the same way, and then clip off the excess wire with a pair of wire clippers. Leave about a millimeter or two of wire above the joint to avoid damaging it.
