It is important to choose the right kind of soldering iron and wire for soldering the through-hole components. You need to be attentive towards aspects including heat, placement of the tip of soldering iron, and others to ensure that soldering is done perfectly and is reliable for the long term.
The through hole soldering technology involves the soldering of components that are inserted through leads within the holes that a PCB (Printed Circuit Board) contain. Soldering is done on the opposite side of the board, and the assembly can be automated or manual. Choosing a good quality soldering iron kit may improve the quality of the work.
For through-hole soldering, it is important to choose a soldering tip having the optimal dimensions. If the tip of the soldering iron is too thin, it will heat the spot of soldering, but cannot be used to solder electronic components. If the tip is too large, it may apply greater heat than desired and may damage the components. Therefore, it is important to choose an optimal ion tip that can heat the components, and melt the solder while not damaging the components.
Soldering wires available today include the leaded soldering wire and the lead-free solder wire. The use of lead-free solder wire is good for the environment. Its use is also mandatory in certain markets, like the European market. It is always better to work with a soldering iron that has a temperature control feature or is microprocessor based. The optimum temperature for working with lead solder is 370° Centigrade to 380° Centigrade. For lead-free solder, the working temperature is around 20 degrees centigrade higher. Because the lead-free solder has additional metal alloys, it requires a higher temperature to be melted.
For through-hole soldering, you should use a soldering iron having a diameter of around 0.7 mm to 0.8 mm. There should be flux at the core of the wire so that you do not have to apply additional flux later on.
Soldering of the Components
Prepare the site of soldering by cleaning the PCB and the leads of the component by using isopropyl alcohol. Wipe the PCB and the component lead by using a kimwipe (particulate free), so that all dirt and dust is removed. Place the component on board by inserting the leads through the holes, so that component gets the requisite position on the PCB. You may be also required to cut the leads later.
To solder the components place, the tip of the soldering iron so that it touches the component and the soldering spot simultaneously. Now you will have to introduce the soldering wire to this area, which will start to melt automatically once it gets the heat. Once the connection has been made, we first remove the wire, and then immediately the tip of the soldering iron. The whole process will not take more than 3 seconds.
Remember that the soldering iron and its tip should only touch the spot, and there should be no force applied. Application of force and pressure will damage the components. If the soldering spot is not heating adequately, you may require a different iron tip, or need to work at a higher temperature. Upon application the solder, it will give the shape of a cone.
Improper soldering and use of low-quality soldering iron kit may result in malfunctioning devices. It is therefore important to follow the guidelines and tips to do the soldering job in a professional manner. Always solder in well-ventilated areas and wear safety glasses and gloves.