Indium Blog

Cooling and Performance Optimized by 80Au20Sn Solder Bond

  • AuSn
  • Gold Solder
  • Thermal Management

  • We’re seeing semiconductor lasers being used in a number of new products from medical to high-speed fiber optic communications. Traditionally, these lasers were used in CD players and laser printers. The advantages of semiconductor laser are their high power capabilities and compact size. With improvements to manufacturing, the cost of these lasers has come down, making them viable options for lower cost devices.

    One of the biggest challenges for semiconductor lasers is thermal management. As operational temperatures increase at the laser diode (active zone), it impacts laser performance and long term reliability. 

    Here are some advantages of the alloy:

    • Strong bond (shear strength 40kpsi) that has good thermal (.57 W/-°C) and electrical resistivity (16 µʊ.cm)
    • With the 80Au20Sn preform you can create a thin bond interface to help with heat transfer to heat sink. Indium Corporation offers preforms .0005” thick and thinner if needed.
    • 80Au20Sn can also be reflowed in a flux-less process and with the right equipment and profile, you can make a void-free bond. Voids in the bond line create hot spots within the solder joint causing premature failures.
    • Gold alloys are creep resistant and don’t wet out of the solder joint.
    • With correct reflow profile we can reduce stresses in the 80Au20Sn solder bond. Please feel free to contact us for any help in setting up right profile. We have experienced tech support engineers to help walk you through the process.

    If you want to know more about more about our gold solder preforms, please send an email to and check out our website: