Everything You Need to Know About Solder Wire

The Latin word solidare means "to make solid," this is where the term solder gets its start. For joining two metal parts, this alloy is used because of its low melting point. Solder is a substance that is used to attach items, basically we can say wires and leads components together. Soldering is considered a skill in electronics for assembly of components onto a bare board PCB. The solder wire used has a significant impact on how well a soldering project turns out.

It consists of alloys, mostly based on tin and lead. Under the ROHS act/ lead free systems, lead-free solder is now readily available nowadays in the market. This article discusses the aspects to consider when selecting solder wire for various purposes, whether you're a hobbyist or a professional.

What Is Solder Wire?

By melting this alloy a suitable joint can be made between the two wires. Although it is not proper welding. We can heat again to separate them properly. The electrical components are securely attached to the PCB substrate by use of solder. It is a form of connective tissue like thing. It is available in a wide range of flux types, diameters, and compositions, all of which are optimized for particular uses. Various thicknesses of solder wire are available, here is how to choose:

• 0.3-0.5mm: For fine pitch components and SMD soldering with hand.
• 0.6-0.8mm: For general Purpose soldering applications
• 1mm and above: For large connectors, especially in power electronics.

How to Choose the Perfect Solder Wire:

Among the many types of solder available to consumers, solder wire is among the most common. It is used in many of the industries in which solder is used. A variety of solder wires are available to accommodate a wide range of temperatures and uses. The solder wire can also vary drastically depending on the type of solder you are interested in purchasing, many different types of soldering wires are available.

Leaded and Lead-Free Solder:

Lead solder wire: It has an alloy combination of lead and tin in it. To keep the melting point as low as possible, we mix tin with lead. What this implies is that when the temperature changes, the solder wire goes from being solid to liquid very quickly. Which decreases the soldering errors basically cold joints and dry joints, which occur due to movement when soldering is curing. Lead solder used to be the standard in the business, but many were wary of using it because of the health risks it posed. It has an alloy ratio of 63/37 and 60/40 these two are the mainly used in leaded one. But while working with circuits the 63/37 ratio is the best suited one.

Lead-free solder wire: Lead-free solder wire includes three components

1- copper, 2- tin the third one silver. Lead-free wires are not as commonly used as lead alloy solder wire just because of their high melting point, which means temperature issues. They necessitate a larger temperature flux because of this. Lead-free solder has a much higher melting point of about 220–230°C in comparison to 180-190°C of leaded one.

Other Type of Lead Free Solder Materials:

Tin-antimony Solder: It is a type of lead free solder and contains 95% tin and 5% antimony. It is used to solder electronics and is specifically designed for plumbing applications. The parts which experience regular high temperature fluctuations and vibrations, such as heat ducts and cooling equipment.

Copper-tin Solder: It is again a second type of lead free solder, which contains 97% tin and 3% copper. It is used for plumbing and water applications because drinking water should not contain any lead contaminants.

Silver-bearing Solder: it is the 3rd type of lead free solder which contains silver, copper, bismuth, and tin. It is used in high precision RF applications and maybe some time in standard electronics.

Solder Types by Core:

Rosin-Core Solder: In this the metal alloy is filled with rosin. A natural pine tree resin and the original flux used in soldering. Solder flows easily and forms a strong link when flux, which is like a weak acid. It removes any minor tarnish from the metals that are joining. By removing impurities it provides a smooth and glossy surface. It is perfect for circuits and electronics because it contains both solder and flux in one.

Acid-Core Solder: Acid-core solder is specifically used in plumbing applications. It contains a strong acid flux, usually zinc chloride or ammonium chloride, Which is used to forcefully remove oxide layers from copper surfaces, in contrast to rosin-core. This facilitates the solder's flow, making a strong and clean bond. To successfully solder copper in plumbing, the strong acidic action is essential for removing oxidation. On the other hand due to its aggressive nature, it has become unsuitable for use in electronics.

Flux-Core Solder: The term "flux-core solder" refers to a more generalized type of solder that has flux filled into internal channels to facilitate the formation of neat and efficient joints. Flux can change in different ways:

• Natural Rosin: Although it is hardly utilized in its purest form nowadays, rosin is sometimes mixed with other cleaning chemicals and isopropyl alcohol to create a solution.

• Organic Flux: This type of flux is suitable for electronics and circuit type work. This flux is moderate enough not to hurt sensitive components. Also it is not strong enough for severely oxidized copper surfaces.

• Inorganic-Acid Flux: It is more powerful than organic flux. The inorganic acid flux removes even the most stubborn oxidized copper, but it also leaves behind residues. Which is harmful to electrical components if not cleaned.

Conclusion

Selecting the right solder wire is important? Definitely, this is exactly what the article tells you. Lead-based solders are best understood, highly dependable, and favored in mission sensitive applications such as aerospace or medical electronics. In order to satisfy health and environmental regulations, electronics can be assembled using solders that do not contain lead. In addition, flux solders have a rosin reducing agent in their center, which is released when the soldering process is underway, thus eliminating oxidation at the bonding site.

By knowing the main elements such as composition, flux type and diameter we can make a decision to use the solder wire. In this blog we have covered all the aspects of solder wire. Using the correct solder wire will ease the soldering process and improve the quality of your work.