Soldering

This page will go over the basics of soldering, such as safety and technique.

Safety

Before beginning soldering, you need to understand the basic safety to ensure you do not hurt yourself or others as you work:

1. Make sure you have a clear work space. Components or tools in your space that you do not intend on using could pose as hindrances or risks while soldering if they get in your way. Move all un-needed materials to their designated areas, or to areas out of your way, before you begin working.

2. Wear eye protection. Solder can 'spit' out whlie you are working, and you do not want this hot metal to get into your eyes.

3. Unplug any circuits you intend on soldering to make sure there is no current running through while you work.

4. Do not touch any metal components on the soldering iron once it is plugged in. These iron run extremely hot and can cause serious burns.

5. Always have the fans on to avoid inhaling soldering fumes

How to Solder

Step 1: Prepare the Soldering Iron

1. Turn on the soldering iron and let it heat up to the appropriate temperature (about 350°C for most electronics soldering).

2. Clean the tip using a damp sponge or brass wire cleaner. A clean tip improves heat transfer and solder flow.

Step 2: Prepare the Components

1. If you are soldering wires, strip the wire using wire strippers, removing about 1/8” to 1/4” of insulation.

2. Position your components (e.g., insert the leads of a component into the PCB).

3. Use helping hands or a PCB holder to hold the components in place if needed.

Step 3: Apply Soldering Flux (Optional)

• Apply a small amount of flux to the joint area. Flux helps clean the surfaces and allows solder to flow better.

Step 4: Tin the Soldering Iron Tip

1. Add a small amount of solder to the hot tip of the iron before soldering. This process is called "tinning" and ensures good heat transfer.

Step 5: Heat the Joint

1. Place the tip of the soldering iron on both the component lead and the PCB pad (or wire ends) at the same time. Hold it there for 2-3 seconds to heat the joint evenly.

Step 6: Apply the Solder

1. After heating the joint, apply solder to the joint (not directly to the iron tip).

2. The solder should flow into the joint and form a shiny, concave shape.

3. Use enough solder to form a good electrical connection but avoid excessive amounts.

Step 7: Remove the Soldering Iron

1. Remove the solder iron once enough solder has flowed into the joint.

2. Let the joint cool naturally for a few seconds. Do not move the components during this time to avoid a "cold solder joint," which results in poor electrical conductivity.

Step 8: Inspect the Joint

• The solder joint should look smooth, shiny, and have a concave shape.

• If it’s dull or uneven, it could be a cold solder joint. You can reheat and add more solder if needed.

Step 9: Clean the Soldering Iron Tip

1. After completing the soldering, clean the tip again on a damp sponge or brass cleaner to remove excess solder and residue.

2. Place the soldering iron back in its stand.

Step 10: Test the Joint

• Check the electrical connection using a multimeter to ensure proper conductivity.

• If the joint is faulty, you can use a desoldering pump or desoldering wick to remove the solder and try again.