Common Soldering Mistakes & How to Avoid Them 

Introduction 

Soldering is an intricate science and skill that requires trained professionals to achieve a perfect result. Along the way, there will be mistakes, which are not uncommon. CE3S is here to help you learn from these common missteps and better prepare for how to fix them when they happen. 

Mistake #1: Overheating 

If your solder joint is too hot, it can damage components and cause issues like lifted pads or burned flux residue, leaving your solder joint ineffective. This could happen if your soldering iron is too hot or there is excessive dwell time. 

You can avoid this mistake by using a temperature-controlled iron and minimizing the time the iron is left on the board. Another tip is to make sure you are using the right tip size for your joint. If the tip is too large, there could be too much heat on the joint at once. 

For advice on the latest soldering stations and tip options, please feel free to reach out to us.  Our team can help support you through even your toughest soldering goals.  

Mistake #2: Underheating 

On the other hand, mistakes can be made if you have cold joints. Underheating results in poor solder flow and dull, grainy cold joints. This could happen if you are using too low of a temperature setting, not preheating the iron well, or the tips are insufficient. 

Using temperature-controlled irons can help prevent this from happening. Also, make sure that you are allowing enough time for the heat to transfer through the lead/pad before removing the iron. Lastly, check your tips and soldering tools to ensure that there are no excess grease or contaminants. 

To better understand your alloy melting temperature, we recommend checking with your solder manufacturer’s website.  If CE3S is your current solder wire supplier, we can easily help you with this type of information.   

Mistake #3: Disturbed Joints 

Another common mistake is moving a joint during the cooling process. This can happen if anything disturbs the board, or components are moved prematurely. 

Avoid this mistake by ensuring components are in place before soldering, allowing cooling to be fully complete, and stabilizing the work area to prevent movement.  

Our selection of PCB holders can help you stabilize your boards while hand-soldering.  For a full list of options, feel free to contact us.  

Mistake #4: Lack of Prep & Cleanup 

You might be so focused on the soldering process that the preparation and cleaning process slips your mind. By not properly cleaning your soldering area, you could be leaving oxidation, which will prevent bonding. Depending on your flux chemistry, residues may need to be cleaned to prevent corrosion or electrical leakage. 

Avoid these mistakes by having a preparation and cleaning process that is mandatory for soldering. Cleaning the pads before soldering can prevent buildup. Also be sure to wipe the tip of your iron off as well as the joint to remove excess solder and flux. 

Having the correct chemicals and wipes/swabs for prep and cleaning are essential.  Feel free to check out our product offerings here.  

Mistake #5: Not allowing enough time for your solder paste to acclimate 

When solder paste isn’t given enough time to warm up after being taken out of refrigerated storage, it can dramatically impact the quality of your PCB or SMT assembly. Cold paste tends to thicken and separate, causing inconsistent stencil printing, clogged apertures, and uneven deposition. This leads to defects such as insufficient solder, poor wetting, slumping, or misaligned components once the board enters reflow. In extreme cases, moisture trapped from rapid temperature changes can even create voiding or solder balling. Simply allowing solder paste to reach room temperature as recommended by the manufacturer helps maintain its rheology, ensures predictable print performance, and protects the reliability of the final assembly. 

You can think of it in this way- according to Lauren Porto of AIM Solder, “When the material is cooler than the room around it, it’s like putting your iced  coffee on your desk and seeing the ice melted after an hour, so you pick it up to toss it out, but there’s still a ton of condensation on the cup and on your desk. Water solubles in particular, will attract moisture and do so at an even higher rate when they’re cooler than the ambient temperature of the room around them.  

The best thing to do is bring paste out of the fridge the night before and let it come to room temperature for use the next day. Linked here are AIM Solder’s recommended solder paste handling guidelines to help you achieve your goals.”  

Mistake #6: Incorrect Solder Type 

You could do everything correctly, but without the right solder alloy or combination, you won’t be able to achieve the desired results. Here are some recommended products from our industry partners: 

• AIM Solder: https://ce3s.productionsupplystore.com/l/aim/ 

• Temperature controlled soldering stations, fume extraction and tips:  Link 

Conclusion

Proper soldering technique is hard to achieve, and there will be setbacks throughout the process. By building better habits and learning how to avoid common mistakes, you can improve your soldering process to reduce costly mistakes and increase efficiency.  

If you would like to learn more about soldering and find the right tools for your needs, contact sales@ce3s.com. Our experts at CE3s are happy to help you get started or improve your current tools.