Eric Bastow: Indium is a very versatile metal. It readily alloys with other things like bismuth, tin, and lead and that gives us a large spectrum, a wide range of melting points, with all those different alloys that we can make. And a lot of those alloys are used as a solder, and indium-based solders are very compatible with thick gold metallizations. Unlike tin, where if you have a tin-based solder and you solder to a thick gold metallization it will become very brittle, indium solders remain soft. Indium is also versatile because it can be electroplated onto surfaces.
The most common electroplating bath is an indium soft-mate plating bath. It's very easy to use, very easy to operate, very easy to maintain, and part of the versatility of indium is that it can be electroplated like that. It does interact with copper. That can be a blessing or a curse, depending on which way you look at it. It does form indium-copper intermetallics, which are kind of stiff and brittle. The blessing part of that is that if you have copper, which as a metal is kind of soft, if you wanted to harden it up, you can actually electroplate some indium on there, let them inter-diffuse and react and form those intermetallics, and it will make that piece of copper stiffer. So, again, indium is a really versatile metal. If you're interested in it, please contact us at AskUs@indium.com.