Indium Blog

Introducing the next generation of flux coatings for solder preforms

  • Flux
  • Solder Joints
  • Voiding

  • Solder joint voiding is tough to deal with. When attaching components, such as power amplifiers/transistors or QFNs, the larger the footprint the bigger the challenge. 

    For some time now I have been suggesting the use of a perform with flux coating as an approach to help reduce voiding.  Logically, if you introduce less flux you entrap less flux. Our NC-9 flux coating is a proven solution.  Many customers are already aware of its advantages, realizing a 50% drop in overall voiding in some cases.  However, given the increasing performance demand on assemblies, the need for even lower voiding is emphasized. Simply removing the paste and adding a preform is no longer enough.  In an effort to meet this requirement, The Indium Corporation has developed the next generation of flux coatings. Our LV-series flux coating is designed to address void reduction primarily, but has additional advantages as well. LV offers:

    • A uniform, repeatable coating as low as .5% by wieght
    • Halide-free without sacrificing strength
    • Low residue gloss coating does not clog pick & place nozzles

    The graphs below show void reduction improvement over our current NC-9 coating for SAC305 and SN63 assemblies.

    To receive the complete details of this report, or, if you would like assistance with void reduction in your application, contact me directly.


    Fig 1