How to Solder in Ten Easy Steps featured image
How to Solder in Ten Easy Steps - Kitronik University Soldering is an essential skill in electronics, fortunately it is easy to get started. Just follow our 10 step guide and you'll be soldering in no time!

Step by Step guide to soldering

1. Start with the smallest components working up to the taller components, soldering any interconnecting wires last. 2. Place the component into the board, making sure it goes in the right way around and the part sits flush against the board. 3. Bend the legs slightly to secure the part. Place the board so you can access the pads with a soldering iron. step-2-place-component-870 4. Make sure the soldering iron has warmed up. If necessary use a brass soldering iron cleaner or damp sponge to clean the tip. wipe-870 5. Pick up the Soldering Iron in one hand, and the solder in the other hand. step-5-soldering-iron-and-solder-870 6. Place soldering iron tip on the pad. step-6-place-soldering-iron-870 7. Feed a small amount of solder into the joint. The solder should melt on the pad and flow around the component leg. step-7-feed-solder-870 8. Remove the solder, then remove the soldering iron. step-8-remove-solder-then-iron-870 9. Leave the joint to cool for a few seconds, then using a pair of cutters trim the excess component lead. step-9-trim-excess-870 step-9-trimmed-excess-870 10. Some connections are made with stranded wire. It is usual to ‘tin’ wire to make it easier to place through the holes in the PCB, and to help it solder successfully. To tin wire firstly strip a small length of the insulation off. The twist the strands together to form a single neat core. With the soldering iron in one hand, and solder in the other place the soldering iron tip at the end of the twisted core. This will heat the wire. 'Wipe' the end of the solder down the twists. This will melt when the wire is hot enough and apply a small amount of solder. step-10-tin-wire-870 A well tinned wire only has a small amount of solder on it, just enough to hold the twist together. It should be possible to see the twisted strands through the solder. step-10-tinned-wire-870

Examples of Solder Joints

The appearance of a solder joint tells a lot about how good it is. A good solder joint is shiny. This means that the solder has not been overheated and exhausted the flux. There is enough solder to form a nice fillet, without excessive solder bulging out. The component leg is ideally in the centre of the joint. This photo shows an ideal solder joint. ideal-solder-joint-870 The following illustrates an acceptable solder joint. The solder is shiny, but there is slightly more solder than required, and the component leg is off centre. acceptable-solder-joint-870 It can be tricky to add just the correct amount of solder when learning. The following photo shows a typical joint with not enough solder. The component hole is not covered. It is possible this joint will work, but it will probably fail quickly. not-enough-solder-870 Slightly too much solder causes a bulge, as illustrated in the following photo. slightly-too-much-solder-870 The PCB tracks are covered in a special paint called solder resist. This helps prevent the solder from flowing away from the joint. As more solder is added it builds into a blob, as shown in the next 2 photos. solder-blob-2-870 solder-blob-870 Too much solder on a joint can cause bridging to adjacent components, leading to a short circuit. Solder contains flux to ensure the joints are sounds and not oxidised. The flux works by reacting with the oxides that are present, and converting them back to metals. Overheating the joint, or taking too long can use all the available flux. This leads to the solder oxidising and what is known as a dry joint. The following joints are also 'Dry'. Note that a dry joint does not necessarily mean that it does not have enough solder, but refers to the solder not 'wetting' the component and the pad correctly to flow. dry-solder-joint-870 Notice the 'Orange Peel; roughness of the solder. This is caused by the metal in the solder turning to oxides. Compare this dry joint with too little solder to the earlier one with too little solder – notice the comparatively dull appearance of the solder on the dry joint. not-enough-solder-870 This joint, with too much solder, is also showing the symptoms of dry joints – notice the dull grey colour, and orange peel texture. solder-blob-870 Overheating a solder pad on a PCB can also cause the copper layer to come away from the fibre glass that the board is made from. This can cause circuit failure when the track on the circuit board breaks, leading to an open circuit. copper-layer-coming-away-870 copper-layer-coming-away-2-870
Lesson No#. Lesson Name. Description.
Introduction. If you're new to soldering our Soldering School will have you up and running in no time.
1 Soldering Equipment Explained. A quick guide to the basic tools you'll need before you start. Includes a video explanation of some tools.
2 How to Clean your Soldering Iron (Tinning). An explanation of why we need to clean the tips and a step by step guide. Includes a video guide to tinning.
3 How to Solder in Ten Easy Steps. A practical guide to getting started soldering. Includes a troubleshooting guide and examples of good and bad solder joints.
4 De-Soldering Demystified. A guide to removing solder. Includes a video demonstration.
5 Simple circuit board repair. Sometimes a pad might get damaged on your board. We show you how to fix it in this simple to follow guide.

11 comments

Kenneth ifechukwude

Kenneth ifechukwude

I love this information i got here a big thanks to the hand on deck here. The Kitronik

Mark Donnison

Mark Donnison

Hi Drew, by all means. We hope the CPD is a success!!

Drew Burrett

Drew Burrett

Hi, I'm running a hands-on CPD session on Practical Electronics with some Scottish Physics teachers in October and would like to use these instructions as the basis for a PowerPoint for the session. I will, of course, give credit for all of the content to Kitronik and link to this page. I'd also be more than happy to share the presentation with you. I'd use the website as is, but cannot guarantee that I will have a reliable internet connection on the night. I intend to use the PowerPoint as an introduction before allowing attendees to practice their skills on the set of 'Learn to solder' LED boards I have purchased for the session. @PhysicsDrew

Mark Donnison

Mark Donnison

Hi Betty, This resource may be of use as it shows how to repair damaged pads: https://www.kitronik.co.uk/blog/simple-printed-circuit-board-repair

BETTY HUNT

BETTY HUNT

Thanks, you describe very detailed tips for soldering on PCB. Really very helpful steps to follow. Please explain what if copper layer come away from PCB, how can we continue to solder on the same spot?

Mark Donnison

Mark Donnison

Hi Anthony, The Iron you have seems to be a decent choice. Maybe get a new tip rather than a new Iron?

gameplayer95

gameplayer95

Any recommendations on soldering irons? I'm currently looking to upgrade my Velleman VTSS4NU (https://www.vellemanstore.com/en/velleman-vtss4nu-adjustable-soldering-station).

Mark Donnison

Mark Donnison

Hi. We sell safety goggles, which you will find here: https://www.kitronik.co.uk/2627-safety-glasses.html and we also have a guide to cleaning your soldering iron: https://www.kitronik.co.uk/blog/clean-maintain-soldering-iron/ I hope this helps.

Wisdom Everson

Wisdom Everson

THANKS..but where can i get soldering mask..and my soldering iron is dull.What can i do

Rob Haywood

Rob Haywood

Thanks Tom!

tom burr

tom burr

keep up the work this is the best site lad

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