There are times when you want to clean your circuit board thoroughly; you might need to remove old solder. But to remove solder, you will need a desoldering tool to work with a soldering iron. But what are those tools?
Now, if you don’t know the different tools for desoldering, then you have come to the right place! If you go through this article, you will learn about different techniques and tools you can use to desolder.
Then you can decide on which method or tool you will be using. And once you are done with deciding, you can start removing solder from different components and boards.
However, before learning about different types of desoldering, you must know what desoldering exactly is. So, let’s begin!
What is Desoldering?
Desoldering is the method of removing solder and components that are mounted on a circuit board. This process is mainly used to remove solder joints. The application of heat is required here.
What Are the Tools Required for Desoldering?
These here are the set of tools that you’ll be needing to get rid of that unnecessary solder.
- Desoldering pump
- Desoldering bulb
- Heated soldering tweezers
- Desoldering braid or wick
- Removal fluxes
- Removal alloys
- Heat guns or hot air guns
- Rework stations or a soldering station
- Vacuum and pressure pumps
- Various picks and tweezers and many more.
Ways to Remove Solder
Braid Method of Desoldering
In this method, when you heat the solder, the copper braid soaks it up. You must keep in mind that a quality solder braid always has flux in it. Also, clean the soldering iron before these steps.
The process follows the following steps:
Choose the Size of the Braid
Firstly, you have to choose the size of the desoldering braid wisely. Use a braid that is the same width or a bit wider than the solder joint you will be removing.
Use a soldering iron
To use the braid, make a hole in the solder joint which you want to remove and lay the braid on it. Then hold a soldering iron up to it so that the solder wick can absorb the heat and transfer it to the joint.
Always select a quality solder braid
Now, in this process, having a quality solder braid is essential. Or else, it will not be able to soak the heat.
However, if you have a weak quality solder, then don’t get disheartened. You can fix it by adding some flux. You just have to add flux to the part of the braid which you will be using. And you must do it before you put it on the joint.
Moreover, if you feel like the joint does not have enough solder, you can add fresh solder to the joint beforehand.
You will observe a change in color
When the solder joint gets melted, you will observe that the molten metal soaks into the braid and turns it to a tin color.
Spool out more of the braid and move to the next section and continue the process until the joint is completely absorbed and removed.
Remove the soldering iron and braid together
Once the molten solder is removed, lift both the soldering iron and braid together in one movement. When you remove the iron before the braid, the solder-filled braid might cool off rapidly and solidify back to the project.
Pump Method of Desoldering
The desoldering pump, also known as a solder sucker or solder vacuum, is used to vacuum small quantities of melted solder when you melt the joints. The manual type is the most trusted version of this tool. It has a reliable suction power and can rapidly remove melted solder. This is the most popular method among the ways to remove solder without a soldering iron.
Set the spring
At first, you have to set the spring of the solder pump.
Heat the soldering iron to a certain temperature.
Heat a soldering iron for about 3 minutes. Make a gentle contact between the soldering iron and the solder joint you want to remove. Use the tip of the iron. Keep heating the solder until it melts.
Use the solder sucker.
Now, touch the tip of the solder sucker to the melted solder and solder pad. Try not to apply any pressure.
Push the release button
After you push the release button, the piston will shoot back quickly. This will create a quick suction that will pull the melted solder into the pump.
Cool off the melted solder
Give the melted solder sometime to cool off and then empty the suction device into the trash.
Iron Method of Desoldering
This method is quite similar to the methods above. It requires a one-piece desoldering iron. The iron comes with a built-in suction component that vacuums away the melted solder.
Apply the tip of the preheated iron to the solder joint you want to remove. As soon as the solder liquefies, the running solder pump will take away the melted solder.
Heat Gun Desoldering Method
- First, remove the PCB from the casings.
- Now, you have to heat the area with your heat gun. Here, you have to keep in mind that you must place the item on something inflammable; also the area around it must be inflammable.
- When you are heating, you will observe the solder turning shiny; that means it’s getting melted. Then, you can remove the solder using tweezers or similar tools.
- You can now place it in a safe place to cool off.
Hot-Air Rework Station Desoldering Method
A hot-air rework station is an excellent tool for small jobs that you need to do quickly. It is a useful tool for removing solder parts from an old circuit board.
The method follows the following steps:
Choose your nozzle
The smaller ones are good for working on smaller components, while the bigger ones are great for significant areas of the board.
Switch on the device
Once you turn the device on, it will start heating up. Aim the nozzle. Always warm up the hot air station before using it.
You might notice little puffs of white smoke emitting from the nozzle. Well, these are normal phenomena, you don’t have to worry about it.
Adjust the airflow and temperature
There are two different knobs for each. Set the airflow and temperature higher than the melting point of the solder.
Apply flux to the solder joint you want to remove.
Aim the nozzle
Now that you did the preparation; it’s time to aim the nozzle at the part you will be working on. Keep moving the nozzle to and fro until the solder starts to melt.
Now carefully remove the part that you need to rework with tweezers. Be careful of the hot air.
Let the device cool off.
Switch off the device to let it cool. Wash the board in case there is any water-soluble flux left. If left, this can cause corrosion.
Compressed Air Desoldering Method
For this method, you only need a soldering iron and compressed air. You must wear protection glasses. This technique is slightly messy but straightforward.
At first, you have to heat the soldering iron. Gently touch the solder joint that you want to remove. Then heat the solder joint and use the compressed air to blow away the solder. And the process is done.
Desoldering with Tweezers
People mainly use desoldering tweezers to melt solder in the right place. The tweezers come in two ways—either controlled by a soldering station or free standing.
Mainly the two tips of the tool are used in desoldering; you should apply the tips to the two terminals of the component. So what is the method of desoldering? Let’s go through that!
Turn the tweezers on
At first, you need to turn the tweezers on and set the temperature. You can check the manual for detailed advice.
To create a good contact between the tweezers and the component, you can use flux or extra solder.
Melt the solder away
For this, place the tip of the tweezers on the area and wait until the solder melts.
Grab the component using tweezers
Now that the solder is molten grab the component by gently squeezing the tweezers.
Lift the part and move it to a new place to release the tweezers.
You can use this tool in case of components with two terminals like resistors, diodes, or capacitors. The plus point of using tweezers is they don’t heat other (surrounding) parts.
Desoldering With A Hot Plate
People generally use an electric hot plate to heat the board to soldering temperature. You will need a flat metal, soldering iron, and soldering wick. The metal is to place your board on the hot plate.
Hot plates are widely used for removing solder bridges off the board. Let’s see the process.
Add solder paste to your board.
You need to add solder paste to your board. You can use a syringe of solder paste for it. This way, you can directly apply solder to the desired pads. And it’s cheap too.
Make sure to place the solder paste between each set of pins. You don’t have to worry about putting too much on it because you can easily remove the extra later.
Place a chip to solder paste.
Now, you need to place the chip to the solder paste and check if it is placed correctly.
Use a metal
Use the metal to place the board on it. Then place it on the hot plate and turn the device on.
Determine the right temperature for the process
You don’t want your board to get too hot that it starts to damage the chips and the epoxy that binds the circuit board. You have to make it warm enough to make the solder flow.
In this case, you must have an idea of the capacity of your hot plate beforehand. Then, put the dial to the right temperature and wait. After some time, the solder will start to melt. You will see the solder turning all shiny.
You will observe some solder bridges.
Fully melted solder now leaves solder bridges. Once the solder is done moving, turn the device off, take the metal with the board off and let it cool down.
Use a desoldering braid and iron.
Now, you can use a desoldering braid and iron for removing the solder bridges. You can follow the process of desoldering braids mentioned earlier.
Desoldering Bulb Method
For this process, you will need a desoldering bulb and a soldering iron. The desoldering bulb uses a vacuum action to remove the solder quickly and easily.
How do you use a desoldering bulb?
Heat the soldering iron and use it to melt the solder you want to remove. Compress the bulb with one hand and touch the melted solder with the tip of the bulb. Release it. This way, the solder will be sucked up into the bulb.
Wait till the solder cools down, then you can remove the tip and release the contents of the bulb.
Although this tool doesn’t allow much suction power, you don’t have a risk of any damage from the suction. You might use this method in case you want to remove a specific amount of solder.
Desoldering With Drills
You can use a small hand drill in this process. Also, you can use a pin vise with a tiny drill bit. Purchase drills depending on the hole size that you need to unclog.
Many people prefer to use drills after using a desoldering bulb. After you suck out the solder with the bulb, you can drill out the remaining solder if there is any.
You should use the cobalt, carbon, or high-speed steel drill bits; but never use the carbide one. And be careful while working with an oversized drill.
Desoldering With Chip Quick
The chip quick removal alloy lowers the temperature of the solder by mixing it with the existing solder. This helps the desoldering process to speed up. It keeps the solder molten for a longer time.
If you intend to remove significant surface mount components like ICs, you can use the Chip Quik. You can remove the SMD components with soldering iron rather than using a hot air rework station.
Once you are familiar with the method of desoldering, it will be a fun task to do! However, you must decide on the methods carefully. You must know which technique is best suited for your job. Understanding the above methods will help greatly.
However, there are so many other ways to remove solder. Like, if you want to remove solder from the circuit board, you can follow the basic desoldering technique which is grinding and scraping.
Milling out the solder is another technique, although it needs high levels of experience and skill. In case you want to remove solder from copper plates, you can do chemical stripping. Moreover, sometimes, you might need to micro blast your PCB while removing solder from a large surface area.
The methods mentioned in this article offer an excellent start to learn how to desolder.