Tips on How to Choose a Lead-Free Solder Wire
Posted by Alphaassembly on January 27th, 2017
Solder used to consist of 60 percent tin and 40 percent lead. These days, it is possible to get a lead-free solder wire, which is favored by many who prefer safer and environmentally friendly products. It is also possible to get halide-free and rosin-free solders. Choosing a solder may sound simple, but there are certain factors you must consider to make sure that you can get the right product. Various types of solders are designed for different tasks, and during the selection process, you need to take note of the flux content, size, and the lead content. Here are a few tips to help you choose a lead-free solder wire:
• Check the flux content – Wetting behavior can be determined by looking into the flux content. Lead-free solders like SnCu and SAC, and SnSb (tin-antimony) wet a bit slower compared to 63/37 when compared to similar conditions during wetting balance tests. Look for a lead-free solder wire that contains at least two percent flux by weight.
• Determine the flux distribution in the solder wire – In a typical flux distribution, the flux’s density is near 1g/cc. This means that the volume is more evident in a cross-section. Some instances may require multiple cores, but the percentage is typically two or three percent for lead-free applications. Keep in mind that less flux results in a difficult soldering process.
• Make sure it is appropriate for lead-free applications - In case, wetting is sluggish at 3 percent, flux in a wire will produce more residue, which may not be aesthetically pleasing in a no-clean application. You may want to avoid flux that is dispensed in a squeeze bottle to prevent over-application. Moreover, make sure that it is designed specifically for lead-free applications. This means that the flux can withstand high soldering tip temperatures without decomposing, spattering, or charring. Some fluxes may emit smoke when exposed to a higher tip temperature.
• Take note of the flux IPC classification – No-clean applications should meet ROL0 classification, which means they are halide-free, low activity, and rosin-based. They are reliable, too, and they meet corrosiveness and SIR tests in the IPC specification.
About the Author:
Alpha Assembly Solutions Inc. is a premier company engaged in the development and manufacture of high quality electronics assembly materials. Since the year of its inception, way back in 1872, the company has played its role on the frontline of innovation, bringing many first-to-market products to the fore thereby, creating a premier niche for itself in the market.
