Indium is an ingredient in many low-melting point solder alloys, helping reduce the energy required to assembly numerous products.
I recently received an inquiry from an area high school sophomore who was doing a paper for her chemistry class on the environmental impact of indium.
Often, questions on environmental impact are inward looking and ask how Indium Corporation obtains and processes indium. But, here was a chance to look at how our customers use indium to benefit the environment.
I provided her this partial list of some fairly common uses of indium that make a beneficial impact on our environment and our lives. Indium serves as a(n):
- replacement for mercury in batteries.
- photovoltaic cell coating and as an assembly solder alloy in solar panels which are used to supplement energy from fossil fuels.
- thermal interface management material for high-end device cooling, reducing operating temperatures by up to 10°C.
- compound semiconductor material ingredient, such as InAs, InGaAs, and InGaN, to manufacture LEDs which use less energy than traditional lighting sources.
- ITO coating, enabling the replacement of the cathode ray tube displays (CRT) with flat panel displays (FPD) resulting in monitors and television screens that are much thinner and easier to recycle and dispose of.
- architectural glass coating - used on buildings to help reduce the infrared (heat) energy transfer in and out of the buildings, reducing HVAC costs. It also keeps out ultra-violet energy, reducing the fading of fabrics like upholstery, carpeting, and curtains.
- gasket used in hermetic, cryogenic, and other mechanical seals. The indium can be easily removed and replaced during the maintenance process. The removed indium can be recycled and reclaimed and used again.
- lower temperature solder that requires less energy input for the reflow process. Several alloys are available.
You probably know that indium is popular for solving a lot of standard soldering and sealing challenges, like coefficient of thermal expansion (CTE) mismatch, thermal fatigue issues, vacuum soldering, drop shock performance, cryogenic sealing, hermetic sealing and low-temperature solder, and thermal management. Now you know it also has the advantage of being environmentally friendly.