Since the NanoBond® process is almost instantaneous, fluxes are not used. (They just don’t have enough time to heat up to their activation temperature and remove oxides.)
So, because this is a fluxless soldering application, surface choice and preparation become very important. We no longer have the chemical power of a flux to break down surface oxides, instead we must make sure our surfaces are ready to be joined.
The first choice to make is: will you have solder on the parts to be bonded, or will you use solder-coated NanoFoil®?
If you decide to use bare NanoFoil®, the parts must have a solder finish such as pure indium, SAC 305, or tin. If you choose to use a solder-coated NanoFoil®, you can bond gold and silver metallized parts.
Need help figuring out what to do? Ask us: AskUs@indium.com
*This post is part of the NanoBond® Process series