Hand soldering is done during PCB rework in a production unit when a PCB gets rejected or fails the quality pass test. Hand soldering is also done for repairing and servicing printed circuit boards by service centers.
The main focus of this article is to make you learn how to solder properly using the best hand soldering methods and techniques. People who are beginners to hand soldering and want to learn the basics of how to solder properly will find this article useful and helpful. Hand soldering is also useful when designing PCB prototype.
Soldering Tools and Materials Needed for Hand Soldering
- Soldering iron or soldering station: You need a good quality soldering iron or temperature controlled soldering station that run on electricity. If you are dealing with ESD-sensitive PCB and electronic components, then you need an ESD-safe soldering station. If you are doing lead-free soldering, you will probably need a temperature controlled soldering iron or soldering station with higher wattage because the melting point of lead-free solder is higher than tin-lead solder. Weller and Hakko are worldwide leaders in manufacturing and supply of soldering tools and equipments including soldering irons, soldering and desoldering stations, hot air SMD rework systems and all other PCB assembly tools and equipments.
- Solder wire: For a good solder joint, you need good quality of solder wire. Solder wires are available in tin-lead and Pb-Free compositions in different diameters. Until few years back, 63/37 tin-lead solder was most common form of solder. But with the electronics industry going green and lead-free, Pb-Free solder have gained popularity. Tin-Silver-Copper is the most common and widely used combination of lead-free solder wire. Kester is a worldwide leader in manufacturing and supply of soldering materials.
- Other soldering materials: Apart from soldering tools and solder wire, you may also need few other consumables like solder flux, solder paste, braid etc. Chemtronics is a worldwide leader in manufacturer and supply of PCB rework material.
Getting Ready for Hand Soldering
Once you are ready with all the tools and equipments needed for hand soldering, you are ready to start the job. Start by making sure the PCB and the leads of the electronic components are clean and free from any contamination such as dust or grease. PCB or electronic components which are not clean may have deposited oxides that can lead to bad solder joint.
Apply a good quality solder flux on the area of the PCB to be soldered and on to the leads of the components. Flux will help to remove any deposited oxides from the surface of the metals thus leading to better solder joints. You can use a flux pen to dispense flux.
Doing Hand Soldering
Now is the time to solder. Make sure the soldering iron is hot. Do not touch it. Hold the soldering iron properly in one hand and solder wire in the other hand. Maintain proper angle between the two. Try to use a solder wire reel stand that holds the reed of the wire so that you can pull the wire properly. Place the solder wire at the point where the lead of the electronic components meet the copper track on the PCB. Apply heat at the point where solder wire touches the lead of the component.
Once done, remove the soldering iron.
Cut extra leads of the electronic components.
A good solder joint should look shiny. Dull solder joint suggests something is wrong. If you are doing lead-free soldering, the joint will look dull in any case.
Soldering Tutorial
The above mentioned soldering tutorial was meant for hand soldering of thru-hole electronic components only. The quality of soldering tools used, solder wire, flux and soldering technique determines the quality of a solder joint.
A good solder joint is the heart of a printed circuit board. The better the quality of solder and solder joints, the better will be the life and performance of the equipment.
Santosh Das - Hi ! I am Santosh Das, an electronics engineer and a professional blogger. Having worked as area manager for an electronics company ...
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