How to Solder Electronics Components (PCB Rework Tutorial)

Have you ever wondered How to solder a circuit board with a soldering iron?

Hand Soldering is a process used to repair, Modify, or connect joints in a printed circuit board (PCB) assembly process. In hand, soldering hot soldering iron tip heats the solder, and it flows inside the metallic surfaces to form a solid joint.

In today’s world of rapid technological advancements, electronics have become an integral part of our everyday lives. From smartphones and laptops to smart home devices and wearable tech, we rely on these marvels of engineering to stay connected, entertained, and informed. But have you ever wondered how these intricate electronic devices are assembled?

Also: What is Flux Used for in Soldering Electronics (Explained)

This Tutorial’s main focus is to teach you how to solder properly and what tools are used in the hand-soldering process.

How to solder a circuit board with a soldering iron

Soldering electronic components is a crucial skill for anyone working with electronics, whether you’re building circuits, repairing devices, or engaging in DIY projects. It’s essential to develop good soldering techniques and take your time to ensure neat and reliable connections.

Before you start soldering, gather the following items:

Tools and Materials

Soldering is a process in which two or more metal items are joined together to make an electrically conductive strong bond between two surfaces by melting and flowing.
Here I will explain how to solder and the main soldering tools and accessories required to make a quality solder joint.
The quality of hand soldering mainly depends on soldering iron tip geometry, Selection of Flex, and instruction followed. Hand Holding is not as easy to work as normal people think.

Materials Needed:

  • Circuit board
  • Soldering iron
  • Solder wire (lead-free recommended)
  • Flux (optional but highly recommended)
  • Soldering iron stand
  • Safety glasses
  • Ventilated workspace (if using flux)

For more information, technical specs, and further details on soldering, check out the Wikipedia article.

Adopting some tools and techniques is required to get a minimum scrap rate, higher productivity, and better PCBA quality of rework consistency.

1. Soldering iron

To do soldering, you need a good quality soldering iron or a temperature-controlled soldering station. Soldering iron good heat source that heats up and cools down very quickly and maintains a constant temperature.

Some worldwide leaders in manufacturing and supply soldering tools like Hakko, Weller, etc., for more details and a buying guide for 7Best Soldering Station for Hobbyists

Soldering irons soldering components are recommended as wattage (15-40 watt) soldering irons, but more powerful circuit boards (60-140 watt) soldering irons can be considered.

2. Solder wire

Solder wire is the main consumable material used in hand soldering. it comes in various thicknesses with leaded and lead-free versions. You use thin solder wires for normal electronic component soldering and thick ones when needed to solder large solder surfaces.

For more information, technical specs, and further details on solder, check out the Wikipedia article. I normally solder around .025″ wire in daily soldering jobs.

4. Other material needed for Hand Soldering
Apart from the above soldering tools, a few other tools are also used to make solid-quality soldering joints.

A list of other tools is a Soldering iron holder, a cleaning sponge, an Exhaust fan, Tools to work with wires like wire cutters, needle nose pliers, a wire stripper, etc., and Safety Goggles.

Getting Ready for Soldering

Once you are ready with all the tools and soldering material, you can start soldering the iron and let it heat up while prepping your materials.

The first thing is to Use the lowest possible soldering temperature (when using tin/lead solder, not higher than 360°С and when using lead-free solder, from 400°С to 425°С).

How to solder a circuit board with a soldering iron – Step By Step Guide

Here is a step-by-step guide on how to solder electronic components:

Step 1: Gather the Necessary Tools and Materials

Before you start soldering, gather the following items:

Choose a soldering iron with an appropriate wattage for your project. Use high-quality solder with a suitable diameter (usually between 0.6mm and 1.2mm) and the right composition for electronics (e.g., lead-based or lead-free, depending on your requirements).

Use these to clean the soldering iron’s tip during the process. Wire cutters will help you trim component leads. Helping hands or a vise hold your workpiece steady while you solder. Flux aids in solder flow and helps remove oxidation from metal surfaces.

Step 2: Prepare the Components and Circuit Board

Place the circuit board on a stable surface and ensure it’s clean and free from debris. Identify the components you need to solder and insert them into their appropriate positions on the circuit board. Ensure they’re oriented correctly according to the circuit diagram or component markings.

Step 3: Heat Up the Soldering Iron

Plug in your soldering iron and allow it to heat up. The optimal temperature will depend on the solder and components you’re using. As a general guideline, temperatures between 300°C and 400°C (572°F and 752°F) are common for lead-based solder.

Step 4: Clean and Tin the Soldering Iron Tip

Clean the soldering iron tip using a wet sponge or brass tip cleaner to remove any debris or oxidation. Apply a small amount of solder to the iron’s tip (tinning) to enhance heat transfer and prevent oxidation.

Step 5: Apply Flux (If Required)

If you’re using flux, apply a small amount to the joint area or directly to the component leads. Flux helps the solder flow and promotes a reliable connection.

Step 6: Heat the Joint

Position the soldering iron tip so it contacts both the component lead and the circuit board pad simultaneously.

Hold the tip against the joint for a few seconds to allow the heat to transfer and warm up the metal surfaces.

Step 7: Apply Solder

With the joint heated, touch the solder wire to the joint where the component lead and circuit board pad meet. Avoid touching the solder directly to the iron’s tip.

Once the joint reaches the appropriate temperature, the solder should melt and flow smoothly onto the joint. Apply enough solder to form a small, concave fillet around the joint. Avoid applying excessive solder or creating solder bridges between adjacent pads.

Step 8: Remove the Heat and Inspect the Joint

Remove the solder wire first, followed by the soldering iron. Maintain the joint’s position until the solder solidifies. Inspect the joint for a shiny appearance and a smooth, cone-shaped fillet. A dull or grainy joint may indicate a cold solder joint, requiring rework.

Step 9: Repeat the Process

Continue soldering the remaining components, following the same procedure for each joint. Take breaks if necessary to prevent overheating the circuit board or components.

Step 10: Clean the Circuit Board (Optional)

Once you’ve completed soldering, you can clean the circuit board using an electronics-specific cleaning solution or isopropyl alcohol to remove any flux residue. This step is particularly important if you’ve used a flux that requires cleaning.

How To Solder Wires Like A Pro Video Tutorial

Defects Due to incorrect use of soldering iron tips

Metal plating tips of soldering iron wear out over time. Plating life of soldering iron tip on a type of soldering application, types of flux and solder paste used, and the soldering skills of the operator.
Generally, the manufacturer does not give any guarantee of soldering iron tips. Usage of defective soldering Iron tips results in soldering defects.

How to SolderHow to Solder

Cracks: – Excessive pressure is applied with a tip to a contact area resulting in a tip bend. it will cause cracks in the tip coating. To avoid this problem, select the tip that best suits your work.

Non-wetting: – Oxidation of tip coating causes heat conductivity reduction due to formed oxides that will not allow proper wetting of molten solder paste. The best remedy to avoid such consequences is to frequently clean the solder tip with a damp sponge; use the lowest possible temperature, not recommend using active solder flux.

Corrosion: –Usage of Active solder paste at high temperature (>450 °C), the coating of the tip can possibly damage partially or completely. For remedy, use less active flux, use clean and damp sponges, and use solder that has an RMA flux type.

Conclusion

By mastering this essential skill, you’ve taken a significant step towards becoming a proficient electronics enthusiast or professional. Let’s recap the key points we’ve covered:

Throughout this blog post, we’ve covered the necessary tools and materials, the importance of proper preparation, and the step-by-step soldering process. Remember to gather high-quality soldering equipment, clean and tin your soldering iron, and apply flux when needed. Heat the joint, apply solder, and ensure a clean, well-formed solder joint with a shiny appearance.

Additionally, always prioritize safety when soldering. Work in a well-ventilated area, wear appropriate safety gear, and take precautions to prevent burns and accidents. Following safety guidelines ensures a productive and enjoyable soldering experience.

So, gather your tools, choose your project, and let your soldering journey begin. With each successful joint, you’re one step closer to becoming a proficient soldering master. Enjoy the process, embrace the challenges, and watch as your soldered creations come to life.

About Author

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  • Manoj Kumar Raghav

    Hello, this is Manoj, A Soldering and DIY Tool expert. Writing is one of my hobbies. With more than 20 years of broad experience. I love researching, discovering, and sharing new products with others, I hope you’ll enjoy the greatest featured products to make life easier, more fun, and more productive.

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