Take Care of Your Solder Tips when Lead-Free Soldering
In the mid-2000s, many electronics manufacturers were in a panic. The European Union had mandated that most electronic products be manufactured with lead-free solder by July 1, 2006, in large part because of concern about the effect of lead in discarded printed circuit boards (PCB) on the environment. This meant that anyone who wanted to do business in the EU had to "get the lead out." But what can be used instead of standard tin-lead solder, which was cheap and worked well? And what are the considerations to equipment lead-free solder presents? One of the most widely used lead-free solders has become SAC305 tin-silver-copper (Sn-Ag-Cu), in large part because of its reduced melting point. In general, however, lead-free solders are not as reliable for mission-critical applications such as military and aerospace. And one problem that's been reported with largely tin-based solders is the formation of tin "whiskers," which can cause shorts in electronics equipment. The generally higher melting temperatures of lead-free solders can cause soldering tip defects and premature wear when hand soldering. This, in turn, can lead to surface contamination and nonwettability. Using Sn-Ag-Cu solder, for example, can erode the iron plating on a solder tip four to five times faster than when using traditional tin-lead solder. To ensure longer life of your soldering tip when hand soldering, proper care of the tip is required. Tip temperature plays a big role in durability. Using a lower temperature, when possible, can mean increased solder tip longevity. Temperature modulation tools (Auto Turn Off) within the soldering station can help you keep the heat off as much as possible. It's also important to clean your solder tip regularly, especially when using rosin-based flux, which is highly corrosive. Cleaning should be done with a wet sponge or brass wire sponge to remove as much flux and oxides as possible after soldering. If conventional cleaning methods do not work, consider using a tip polisher like the Hakko FT700.