Indium Blog

High Purity Indium Ingot for the Compound Semiconductor Industry

  • Indium

  • The compound semiconductor market requires high purity indium. Today, we’re going to discuss what “high purity” actually means in terms of indium, and how that is verified.

    For most applications, indium is commonly purchased at 4N (99.99%) purity. As a solder interconnect, 4N purity is fine. 4N5 (99.995%) and 5N (99.999%) pure indium are most common for applications such as cryogenic sealing; applications that really utilize the most unique properties of the element – such as cold welding, malleability, and softness near absolute zero. Chemical reactions and physical deposition processes require even higher levels of purity: 6N (99.9999%) and 7N (99.99999).

    When you’re dealing with critical applications, you should demand verification of the purity of your raw materials. At Indium Corporation, this is standard documentation for high purity indium. A full Certificate of Analysis is included in each shipment, with a breakdown of elemental impurities. For more information on our material certification or help with material selection, contact us at


    Authored by previous Indium Application Manager Jim Hisert