[ we make science jokes, periodically ]

Soldering: Tape of Electrical Engineering

Soldering is the tape of electrical engineering. You might use tape when you need to connect two pieces of paper, but you will use solder when you need to connect two electrical components.

You can solder two or more components in three basic steps:
1. Place your components together
2. Heat them with a soldering iron
3. Apply solder, allowing it to flow over the components

It seems easy enough, but there are many details.
Ready? Let's get into it.

The first step is easy; most components you would solder are made to be soldered, so they have holes or pads that are designed for the part to go through the hole or be placed on top of the pad.

Next is applying heat to the components. This can be more difficult since some things will need more heat, some less, some will melt (when they arenโ€™t supposed to), and some might burn. This will depend entirely on the component and will require some testing.

Last is the solder. Solder looks like itโ€™s just a string of metal and it is that. But it is also a very particular mix of different kinds of metal. This alloy is designed to melt at a relatively low temperature, flow, and be stable over time.

Thereโ€™s also an acid known as flux in solder. Flux is what makes the solder stick to metal, without it, you would end up with lumps of metal that won't stick anything to anything.

A lil blurb about lead.
Leaded solder was commonly used because it was ideal: it melted at a low temperature, flowed like honey, and was very stable. Although leaded solder has since been replaced with non-leaded solder, leaded solder can still be bought. Despite it being easier to work with, it is always best to avoid lead.


Soldering irons usually come with removable tips and it's important they are taken care of. Being exposed to high heat, different metals, flux, and solder take their toll. When a tip isnโ€™t cleaned, the solder will stick to it instead of flowing where you want it to go. So youโ€™ll need two things to keep it clean: a ball of metal mesh to clean the tip and tinner, which puts a coat of a particular kind of metal on the soldering iron.

While we're on the Take Care of Your Things train, consider working on a mat! You are working with molten metal, after all. It wouldn't take too much to burn surfaces. A small fan blowing away smoke and fumes is also a great idea!