HOW TO SOLDER CORRECTLY?

SOLDERING

Soldering is one of the essential skills in all aspects of electronic component design - from creating pins for circuit board assembly to commercial operations, including students and DIYers.

Soldering is a skill that is essential for anyone interested in the design of electronic projects and circuits. Knowledge of the soldering process and proper methods is essential not only for quality solder joints, but also for an aesthetic project appearance that you can be justly proud of.

Although soldering has been known as a method of joining pin components for many years, it is still used as a standard method in electronic assemblies. It is a simple and effective method that, when done correctly, produces quality and reliable electrical connections.

Surfaces and tools for soldering

Before starting soldering, everything necessary must be provided, in particular a suitable working environment, workplace equipment and the necessary tools.

Tools: the most important thing is a good quality soldering iron. In addition to this, you need a pair of small pliers, perhaps round nose pliers, wire cutters and other tools depending on the nature of the work to be done. For most modern work, where parts are getting smaller, the tools should not be too large.

Work area: A suitable work area - well lit and adequately ventilated - is needed for the work. A side spot light with the ability to focus on the object is ideal. Often a small fan is sufficient to remove fumes from the flux.

Anti-static protection: Static electricity can cause problems, especially with integrated circuits and semiconductor components. It is therefore advisable to work in an electrostatic discharge (ESD) protected environment and with an antistatic soldering iron. The work surface should be provided with an antistatic pad.

Preparation for work

Cleanliness is essential when soldering. Dirt and grease on component pins, wires or solder pads on the PCB make soldering difficult and prevent a quality joint. Oxidized surfaces also hinder wetting and solder adhesion.

A few points for a quality solder joint:

Check surface cleanliness: Before starting soldering, check that the soldering surfaces are clean and free of oxidation. If necessary, wipe them with a solvent to remove contaminants. After cleaning, do not touch these surfaces.

Clean oxidised surfaces: the pins of components often oxidise, so these oxides must be removed. Grasp the pin in the pliers and gently pull it between the jaws.

Clean the connector housings. For some of the cheaper connectors, a gentle roughening with sandpaper will help.

Clean the soldering tip: The soldering tip quickly becomes contaminated with flux residue, which must be removed. Most soldering iron stands have a bowl with dry wire that you wipe the tip against regularly.

Tinning

Proper tinning is crucial for a quality solder joint. After tinning the tip, the solder adheres better.

Solder tip tinning. If it is not, wipe the tip with a wire brush and repeat the process.

Tinning wires and soldering surfaces: components should be tinned before soldering. Apply a small amount of solder to the desired area and spread it over the entire surface.

Once all parts are tinned and ready, you can proceed to the actual soldering.

Making solder joints

Placing the part/wire: Place the part where it is to be soldered. For wire connections, thread the pins through the holes in the PCB.

Cleaning the soldering tip: Wipe the tip with a wire cloth and apply a small amount of solder to it, which will improve heat transfer to the joint.

Soldering the joint: Apply the soldering iron and solder at the same time to ensure that the solder evenly wets the entire joint. Be careful not to overflow solder around the joint. The soldering itself should not take more than a few seconds.

Remove the soldering iron and allow the joint to cool: After soldering, remove the soldering iron and allow the joint to cool, it is still hot to the touch for a while.

Checking the soldered joint

Visually inspect the joint using a magnifying glass, microscope or endoscope.

The amount of solder: the joint should be slightly concave. If there is too much solder, the curvature has a convex shape.

Cold joint: The joint should be shiny. If it is dull, a grainy texture indicates a cold joint, which may be the result of too much heat or shifting on cooling.

The golden rules of soldering

Safety first: Soldering irons are very hot, always use a stand and do not allow children to be present.

Correct choice of tip shape: Tip shape is important for the efficiency and quality of soldering.

Keep the tip clean: Wipe the tip frequently with a dry wire.

Use the soldering iron and solder at the same time.

Do not use too much solder.

Lead-free soldering: Lead-free solder has a modified lead-free formulation, but requires procedures to be followed.

The art of soldering well is an essential skill for anyone who assembles electronic circuits. A good joint will ensure the long-term functionality of the circuit.

Solder joints

Good joints: a good joint has a shiny surface and a slightly concave shape.

Cold joint: These joints can cause problems - they are dull, grey and grainy. If you discover a cold joint, remove the solder and make the joint again.

These rules are the foundation of quality soldering, whether it's for commercial practice or DIY projects.