How to avoid common PCB soldering problems

In this article, we’re going to explain the most common PCB soldering problems you’re likely to face. More importantly, we’ll help you to steer clear of these obstacles so that you can complete your PCB assembly without any major issues.

Soldering is an important part of the Printed Circuit Board (PCB) assembly process. Unfortunately, soldering is a tricky task that can cause a number of problems. This can impact the quality of the PCB you are working on and leave you with substandard results.

Excess solder

This is a fairly common problem, particularly with inexperienced practitioners. When it comes to solder, applying more isn’t always good. Knowing how to use just the right amount of solder is an important skill that will contribute to the overall result of your work.

In the case that you apply too much solder, you can remove this in a process known as desoldering. Here are some of the ways you can remove excess solder:

  • Sucking it up with a solder pump
  • Removing it with a solder braid/wick
  • Reheating the solder with a soldering iron and loosening the components

We have produced a guide explaining the basics of desoldering that covers these techniques in more detail. If you’re new to this process, be sure to remember basic soldering health and safety while you work.

Solder balling

During the PCB soldering process, you may notice the appearance of small balls of solder sticking to conductor surfaces. These can be caused by poor reflow temperature or when you used oxidised components. Keeping your soldering iron tips in good condition will help you to avoid this problem.

Cold joint

If you have noticed that the joints on your PCB assembly look dull and lumpy, then you have a problem. This has probably been caused by cold joints, which means the PCB soldering temperature was too low for the joint to melt properly.

The most likely cause of this is that the soldering iron hasn’t been given sufficient time to heat up properly. Soldering irons are designed to reach temperatures of ​​200 to 480 °C, but this doesn’t happen immediately. Make sure you are using your soldering iron properly and giving it enough time to heat up. 

Whatever you do, don’t ignore cold joints. They need to be resolved as soon as you notice them, otherwise, the structural integrity of your components will be at risk.

Overheated joint

While you need to make sure your soldering iron is hot enough to melt the solder, you want to avoid overheating your solder at all costs. This can cause severe damage to your PCB, the other components and even your soldering iron tip

To avoid this, make sure the temperature of your soldering iron is configured to the right setting. JCB soldering irons can be set to reach an exact temperature so you can be certain that there’s no risk of underheating or overheating your solder.

Solder-starved joints

This problem can occur when an insufficient amount of solder is applied to form a reliable electrical connection. This PCB soldering problem can be hard to notice because the connection might work at first but then slowly become less reliable over time. Eventually, the connection will become faulty and you’ll need to fix it.

Luckily, this problem isn’t too difficult to resolve. You will need to reheat the joint while adding more solder. Make sure this time that you’ve added enough solder to form a strong electrical connection, or you’ll be back at square one. We stock a range of different types of solder wire.


Manufacturing environment 

If you feel like you’ve resolved all your other issues but you’re still not getting the results you want, then it might be because of your working conditions. Environmental conditions need to be controlled while soldering because factors like humidity can have a serious impact on the way solder and components act when assembled.

It’s also important to make sure that your workstation, equipment and clothing is clean and free of debris. Even small amounts of dirt or dust on an assembly board can cause problems during manual PCB assembly and therefore precautions need to be taken. 

Take your PCB soldering to the next level

Now that you’re aware of some of the common PCB soldering problems, you should be able to enjoy better results from your work. Avoiding these issues will help you to get into a good rhythm while soldering and minimise the time you spend rectifying little mistakes.

We understand the need for precise and reliable equipment, particularly for more complex and intricate PCB assemblies. In our experience, JCB is the stand-out manufacturer of soldering equipment.

From fully customisable soldering stations to high-technology handpieces and a range of accessories, JCB really has every base covered. To find out more about PCB soldering or any products we supply, get in touch with us today.