What does solder actually do in electronics?

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I understand that part of it is for structural support, but what else is it for?

In: Technology

It is basically just conductive glue. It holds electrical components in place and allows them to conduct electricity along a path between them and the next components in the circuit.

It’s a means of connecting wires to wires, or wires to circuit board, which means energy/data needs to be passed through it. It is structural – but also conductive; meaning any electronic signals can still pass through solder and into whatever the solder is connected to.

Conducting electricity between the boards and/components you want connected to a board or circuit.

Eg. Printed circuit board (PCB) had circuits built into it when they fabricated it. There are bare metal pads or metal plated through holes for surface mount or through hole components.

In the most basic method, you place the component you want connected to the board on the pads or on the metal plated through hole. Then heat the metal pad and the component with a soldering iron and then melt solder onto the two, creating a structural and electrical connection.

It’s a metal alloy that is easy to melt at relatively low temperatures but solidifies very quickly. It is loosely similar in concept to welding, but doesn’t require extreme conditions to actually melt. The key difference between soldering and welding is that welding is intended to be very strong whereas solder is meant to conduct electricity, join electronic circuits, and not much else. It’s easy to work with and can fill very small gaps.

Solder connects everything together and completes a circuit.

We need a way to reliably connect the legs of a component to those of another component, or two the trace on a circuit board. This has to both physically holy the two together and stop them wiggling apart, and it also has to provide a conductive bridge so that the electricity can flow from one into another.

Solder is a metal that has a fairly low melting point, so we can melt it into a liquid and let it flow between two components, when it then cold down and hardens it will both physically hold the parts together (like mortar holding bricks), and also electrically, so electricity can flow from one to the other.

If you experiment with electronics, you can use things like protoboard to ‘wire’ components together, connect things together with crocodile clips, leads and many other solutions, but these solutions are all generally pretty temporary – they will work, but are fairly unrealities and won’t stand up to getting knocked or shaken about.