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Interview: Properties and Application of Indium Metal (Part 3)

Back in 2013, Carol Gowans was interviewed by Kalwinder Kaur for an article which appeared on AZO Materials’ website. The full article can be found here. I thought they brought up many good points – let’s take a closer look:

Question: How do I know when to consider indium as a solution for bonding or soldering?

Answer: Indium-bearing alloys work very well in the following applications:

  • Soldering two metals that expand at different coefficient of thermal expansion rates (CTE mismatch). With most solders, different expansion rates can result in a cracked solder joint. Indium accommodates the differing expansion rates, cushioning the joint.
  • Assembling devices that see regular heating and cooling cycles when in service. Thermal cycling can compromise a standard solder joint. Indium reduces thermal fatigue-related joint failures, reducing field failures and assuring product quality.
  • Multiple soldering steps or step soldering. Several indium-containing alloys reflow at temperatures below 183°C. This allows for a subsequent reflow step that does not disturb the initial solder joint.
  • Bonding non-metallic surfaces like glass, ceramic, or quartz. Indium metal wets very well to these materials.
  • Using components that cannot withstand the reflow temperatures needed for conventional soldering. Many indium-contained solders reflow at less than 175°C.”

If you want to explore indium or other alloys for your application, why not contact the friendly engineers at [email protected]?