Soldering can be described as a reliable way for joining copper pipes during plumbing works as well as for assembling electrical components inside a printed circuit board. This creates reliable and strong joints.
However, what will happen when you solder a wrong pipe or component? What if the soldered pipe or component has no use and you want it to serve a different purpose? This is simple; all you need to do is to take out the component by desoldering this solder joint or melting the solder. Whenever you are Desoldering, you must choose the appropriate tool and method for removing these components. By this, re-using the components will be possible.
Otherwise, these components will become damaged during the whole process and using them again will be impossible.
What are Desoldering Wires?
A desoldering wire, which is also called desolder wick, is made up of copper threads which are braided together. Normally, flux is added to aid the flowing of the solder from the jumper, where it isn’t meant to be, into the wick. Therefore solder wick is at times referred to as desolder braid. You can solder virtually everything, and the desoldering wire forms a huge part of the entire process.
This method of soldering wick is useful for taking out any unwanted solder after the soldering process. The making of the soldering wick is made through the intertwining and braiding together of the copper coils. Therefore, it is termed desoldering braid.
Furthermore, soldering wick is manufactured using copper wires because they are great heat conductors. As this solder gets attracted to heat, these copper coils suck the solder up from the surface of the metal.
There are soldering wicks that come with flux. This allows solder to be removed from its surface. Also, when the solder wick doesn’t have a flux, you may dip the wick’s end part into some of the flux so as to enhance the solder removal speed. Three types of desoldering wires are possible to serve different uses. These include:
- No-clean: These are low-residue halogen-free flux coated braids that are spooled on the ESD safe ribbons.
- Unfluxed: The copper braid left untreated and spooled on the ESD safe ribbons
- Regular: This is the rosin flux having treated copper braids
Things to Do To Desolder
Below are some of the things you must do to desolder
- Intertwine few inches of the copper wire and then create a braid
- Then apply some of the flux on this copper braid through the dipping of the end in flux
- Place some of this solder wick on those joints you wish to desolder
- Keep the hot soldering iron at the solder wick’s tick as well as the desired pin
- Wait for some seconds till this solder melts and the melted solder is sucked by the solder wick
- Take this solder wick and then take that part of the wick, which has been covered using solder
- Then, repeat this process until this unwanted solder has been removed.
When handling this solder wick, make sure that it isn’t touched with your bands because of its extreme hotness. Just use some pliers to hold as well as position it.
What are the Safety Tips to Take Note of During Desoldering?
Similar to soldering, there are some safety precautions that you must adhere to strictly during desoldering. If you fail to do this, you could have serious injuries.
Work with these safety tips in order to have a safe a great desoldering experience
- User well-ventilated areas during desoldering
- Avoid touching the element or tip of the soldering iron
- After use, ensure the soldering iron is placed on its stand
- When handling the components, use pliers during desoldering
- The solder must not be touched with your hands
- Make use of gloves, masks, and safety glasses
- Don’t put on loose-fitting clothes
- Have a fire extinguisher and first aid kit ready
When Should a Desoldering Wire be Used?
While the desoldering pump or solder sucker functions like the vacuum cleaner, the desoldering wick functions more like mops. The ability of the latter for absorbing solder ensures it is very useful in applications whereby solder splatter cannot be accepted.
This makes this desoldering wick better when cleaning off solder from the SMT pads as well as removing the solder bridge found on the BGA pads and fine-pitch SMT which are usually seen on modern PCBs that have been populated with the SMD components. Though the best way to desolder the SMD components are by making use of the hot air rework stations as well as special desoldering tweezers the desoldering wire or wick is also utilized for this task.
Also, the desoldering pump is clearly useless for all SMD reworks. This is due to the fact that the PCB’s conductive pads are just too flat to allow the sucking out of the solder effectively. It is similar to drinking of soup from your dinner plate using a straw.
Removing Solder Using Desoldering Wire
Using the desoldering wire wrongly might tear patters from the PCB as well as damage some discrete components. To prevent problems like these, ensure these [preventive measures highlighted below are taken.
- Apply flux to whatever joints you want to desolder
- Place your desoldering wire on the joints and place this soldering wire on a wire
- This soldering iron will melt the solder. This is pulled in the desoldering wire. Immediately this solder has been taken out, lift this wire and then iron the board off.
Tips for Proper Removal
Though using it seems easy, utilizing wrong techniques might lead to thermal damages to the printed circuit board and its components. Extending the soldering iron contact to the component or board might lead to thermal damage. Also, if this desoldering wick doesn’t remove the solder, try the steps highlighted below.
- Apply a little solder onto the joint
- Also, apply some solder to the soldering iron tip
- Apply little quantity of solder at the desoldering wire tip. This aids easy removal
- Cut the wire’s soldered tip at a 45 degree angle. This ensures that solder present at its tip isn’t cut off
When you apply some solder to the joint, the tip of the desoldering wire, this helps to cut surface tension as well as permit the easy absorption of the joint’s solder by the wires.
During the process of desoldering, if you need to cut the desoldering wire, cut it at an angle of 45 degrees with the solder still present, this also helps in trimming the wire whenever it is saturated with the solder and will not be able to absorb again.
Choosing the Right Desoldering Wire and Tip
Below are some things to consider when choosing the right desoldering wire and tip
Braid Width
You can find desoldering wick in different widths starting from 0.8 mm and can go above 5 mm. A general rule says that the width of the braid must be slightly larger or equal to the size of the pad. Braids that are smaller won’t wick off solder from the whole pad, whereas the oversized ones would affect the nearby pads that you didn’t plan to solder
Size of Soldering Tip
This same logic is applicable to the tip of the soldering iron. It has to match the width of the braid. When it is too small, the heating becomes slower. This causes the dwell time as well as the risk of damages to the components. Also, the oversized tips may knock the neighboring components off.
Flux Composition
Finally, the composition of the flux utilized for the desoldering wick is important as well. If the workflow is relying on no-clean solder due to the fact that you want to do skip cleaning, then you have to make use of a desoldering wick which has no-clean flux infused with it. Also, if you want to clean the post rework of your PCB assembly, desoldering wick that has been imbued with a rosin flux ill have the fastest wicking action.
Advantages and Disadvantages of Desoldering Wire
Advantages
- Simple, cheap, and easy method
- Great method for taking out solder from the flat surfaces
- Desoldered components can be reused
- Supplied on pre-cut or spool strands
- Soldering wick comes in different sizes; this depends on the quantity of solder that you wish to remove
- The soldering wick’s size can be modified. This depends on the quantity of solder that you wish to remove
Disadvantages
- The soldering wick cannot be reused. The portion that is covered in solder must be cut
- As this soldering wick become very hot, positioning it against its joint could be difficult
- With this method, removing solder out of pinholes could be difficult
Conclusion
In summary, the process of desoldering is utilized in melting the solder as well as removing the materials that have been soldered. By making use of the right methods and tools, you can take out the components without causing any damage and then reuse them.
