DIY Soldering and Desoldering

In this tutorial blog, you will learn basic soldering skills. It’s an essential skill to learn, and everyone should know it. All you need is a soldering iron and a Solder for basic soldering. If you disassemble any electronic gadget with a circuit board, you’ll notice that the components are connected using soldering procedures. So, If you want to repair or create any electronic device, this skill will always help you.

Components Required

• Soldering Iron
• Soldering Iron Stand
• Solder wire
• Flux Paste
• Wire Cutter/ Nipper
• Copper Mesh/ Sponge
• Desoldering Pump
• Desoldering Wick
• Fume Absorber
• Helping Hand
• Magnifier
• or Soldering Kit

Soldering is the process of melting Solder around a connector to join two or more electronics elements together. Solder is a soft metal compound that establishes a strong conductive link between the components as it cools. Do not use a plumber’s Solder; look for Solder with a rosin core 60/40 type (a mixture of 6% tin and 40% lead) which has a melting range of 183°C to 190°C or one of the lead-free solder that are designed for electronics soldering with a slightly higher melting point about 217°C(99.3% Tin and 0.7% copper). It is a wire-shaped Alloy sold coiled in the spool. Even though soldering can create a permanent connection, it can also be reversed using a desoldering tool. 

Flux Paste/ Liquid

Liquid flux is a chemical agent used to prepare your board for soldering. A flux bottle has a needle that allows for precise application of the flux. In soldering, flux is a compound that prepares a surface base metal so that it can be joined efficiently with Solder.

• It reduces oxides to prevent oxidation during the soldering process.
• Flux also assists in wetting which is the process of reducing the surface tension of the base metal so that the liquid Solder can make better contact with it.

Think of a bead of water on a newly waxed car to get a better sense of wetting. The water forms a bead because of the greater surface tension of the waxed surface. In other words, the water does not make good contact with the surface.

• The flux prevents the beading of Solder, enabling the Solder to adhere as a flat droplet instead of an angled bead.

Solder is often sold already combined with flux, in the form of rosin-cored or flux-cored Solder. This is often all the flux you need in a basic printed circuit board (PCB) Solder. If you are working with surface-mount soldering, you may also want to prepare the surface of the PCB and the component itself with additional liquid flux.

Rosin is a pine tree that has been used as a flux for many hundreds of years for its ability to reduce friction.

Soldering Iron and Tips

A soldering iron is a tool used to melt Solder to form joints. It has a plastic handle and a metal tip that heats up. The type of soldering iron we recommend has variable power but no temperature control. Generally, if you are just starting out in electronics, you should look for a relatively low power unit (25-50 W) that can accept a variety of tips and comes equipped with a stand. Our iron stand has a place for sponge for wiping off any solder residue after each use. All types of Soldering kits are available on our website for all types of users, from beginners to professionals. 

You will also want at least two different types of tips: one with a flat head much like a screwdriver (this is one that will come with your iron) and one with a fine point. Tips are usually made of a copper core because of copper’s conductivity. The tips are then covered with iron, chrome and nickel to provide hardness and better high-temperature performance.

• Conical Tip – Because of its pointed end, it is used in precision electronics soldering. It can distribute heat to tiny areas without impacting its surroundings.
• Chisel Tip – Because of its broad flat tip, this tip is ideal for soldering wires or other bigger components.

Preparing for Soldering
Before beginning a soldering project, you must first prepare your workspace and materials. Make sure you have adequate ventilation so the irritants in the flux and Solder are diluted by fresh air, or you can use fume absorber available on our website. You should have adequate room to work and to organize your equipment and components. Make sure components and the board you are using are clean. Use a brass Sponge (with no soap) or IPA to remove any wax or oily substance.

Cold Solder Joints Must Be Avoided!

Always make sure there’s enough heat on Both the pad and the pin. You might wind up with a chilly solder joint if you don’t.
At first inspection, a cold solder junction may appear to be in good condition. However, if you look closely, you’ll notice a small space between the Solder and the pin. This indicates that the pin isn’t linked to the pad properly.

1. Make sure your iron’s tip is clean and shiny. Know which part of the tip is the proper work area.
2. Prepare your sponge by dampening it (not soaking it wet until it is dripping wet).
3. Turn your iron on. Follow your manufacturer’s instructions for the proper settings for the Solder you are using.
4. Wipe the iron’s tip on the damp sponge and apply a bit of Solder to the tip to tin it. Tinning helps in the even and quick heat transfer from your iron to the Solder, so even your tip is pre-tinned, it’s a good idea to re-tin every time you wipe the tip with the sponge. You can also buy the tinner, which is a dip-in product that cleans and tins tips.

• Don’t touch a hot iron’s tip.
• Don’t leave a hot iron unattended.
• Don’t set a hot iron on anything but its stand.
• Please wait until the iron has cooled completely before storing it.
• Know where your fire extinguisher is. Be sure it is rated for electrical fires (Class C) and is up to date.
• Keep the iron’s power cord out of the way, so you don’t risk tripping over it.

Soldering technique

1. A Steady hand is always your best tool. Hold your iron with a comfortable, relaxed grip. Then follow these steps: If you are soldering a particularly heat-sensitive component (such as a transistor), attach a heat sink to the lead.
2. Before you start soldering, you should tin the tip of the soldering iron. Which just means to melt some new solder onto the tip. This makes the tip transfer heat faster and thereby making the soldering easier and faster.
3. If you end up with big droplets of tin on your tip, just clean it using a wet sponge, a copper Mesh, or something similar, as shown below.
4. Heat the connection you want to make, not the Solder. Hold the connection with the tip for a few seconds.
5. Apply a little solder and let it flow into a small volcano shape over the connection.
6. Remove the Solder, then slowly remove the iron, all while maintaining a steady hand so as not to disrupt the joint.
7. Keep everything still as you inspect the joint. It looks like it needs more Solder. Repeat steps 2 through 5.

Don’t worry if you make a mistake. You can always remove the Solder and reapply it.

Soldering Iron Tip Cleaning

Using a wet sponge help you in keeping the soldering iron tip clean by removing the oxidation that forms. Tips with oxidation will tend to turn black and not accept Solder as it did when it was new. You could use a conventional wet sponge, but this tends to shorten the lifespan of the tip due to expansion and contraction. Also, a wet sponge will drop the temperature of the tip temporarily when wiped. A better alternative is to use a copper mesh or brass mesh for tip cleaning. 

De-soldering
Desoldering Pump and solder wick is used to suck up excess Solder from your projects. A solder wick does the same sort of thing but is more precise. You typically use the sucker first to get the bulk of excess Solder off and then use the wick to remove what’s left.

1. Clean the area around the solder joint. Again, steel wool should do the job nicely.
2. Gather your tools: soldering iron, solder sucker and soldering wick.
3. Heat the joint to melt the Solder.
4. Depress the plunger on the solder sucker: when the Solder melts, use the solder sucker to take up the Solder. This may be the only step you need to take to remove all the Solder.
5. If there are bits of Solder left, heat a portion of solder wick (enough to hold the remaining Solder) and place it on the remaining Solder. It should suck up the remaining Solder.
6. Clean the area with steel wool to remove any remaining rosin or solder bits.