Important Industrial Solder Alloys and Their Uses

Knowing the right solder alloy to use for your application is critical to the success of any project. If the proper solder alloy isn’t chosen and correct plating requirements aren’t defined or flowed, it could result in rework and excessive scrap, or worse the failure of your application. There are many different types of solder alloys and concentrations used for all kinds of applications, but it is important to first have a general understanding of solder and how it works.

Solder is basically a metal wire that has a low melting point (or low enough for melting using a soldering iron). For electronics, solder is usually made from a combination of lead and tin. Tin has a much lower melting point than Lead, which means that higher tin concentrations means a lower solder melting point. Typically, you would find 60Sn/40Pb lead-based solders at gadget stores, although other minor variations are also sold. For industrial purposes, however, you would typically find two major categories of solder alloys, namely, flux cores, and lead-free.

Flux cores further comes in two common forms, such as Acid and Rosin. Acid flux core solder alloys are ideal for plumbing use and cannot/should not be used in electronics as it will likely erode your boards and components. For electronics purposes, choose rosin core. Lead-free alloys are what industry regulations and standards are leaning more towards. Because the EU is now requiring pretty much every commercially available electronics to use lead-free parts and components, this also means more demand for lead-free solders. Lead-free solders pretty much work exactly like lead-based solders, only they are more environmentally friendly. Lead is believed to be a very toxic material, which is why safer metals are now being used in its place. Lead-free solders, however are a lot harder to work with, as replacement metal alloys behave differently and don’t flow as well as lead.

The Secret to Perfect Solder Lines

Soldering is a valuable and critical skill to learn in many electronics and assembly applications. Achieving professional quality soldering requires clean, smooth, and uniform solder lines. Perfect solder lines are not only a sign of quality and craftsmanship, but also of durability and value, which is why perfecting soldering techniques is a must, especially for professionals who want to improve the quality of their work. While there are no hard and fast rules for perfecting solder lines, these guidelines will help you enhance your skills, build your confidence, and increase your precision in soldering:

• The perfect soldering lines start with the right tools. Choose high quality soldering equipment and supplies to help you avoid common mistakes and difficulties in soldering perfect and precise lines. Soldering irons with ceramic heating element and temperature controller (built in or separate) are ideal along with solder with a 60-40 mixture of alloys. Non-smoking, odorless liquid flux is also preferred.

• To perfect your lines and increase your precision takes a lot of practice and requires an understanding of how your own equipment works. Spend time practicing your lines and discovering the perfect temperatures or temperature ranges that create more refined lines as you work. It helps using a wet sponge or an abrasive pad to wipe off your iron’s tip periodically to keep gunk and residue from building up. Slow, constant strokes are ideal for creating perfect soldering lines. It is also better to keep your solder at a manageable length to help you keep your strokes consistent.

• Avoiding common problems will also help with perfecting your technique. Pits or bubbles, for instance, are typically caused by too much flux, while too little flux results in uneven and uncovered portions. Lumpy lines could mean that your iron isn’t hot enough, while spits and sputters may likewise be caused by excessive flux. Flat lines mean that your iron is moving too quickly or that you are using insufficient amounts of solder. Bulges on the other hand, mean slow movements and excessive use of solder.