Indium Blog

Solder Redefined Part 4 – Baseplate to Heat-Sink

  • Indium
  • Solder

  • Seth Homer: At Indium Corporation, we're redefining how we use solder at the die-attach, DBC to baseplate, and baseplate to heat-sink levels so we can achieve a more reliable IGBT that can perform at increasingly higher standards. If you missed the first three videos in this series, get caught up at
    Today we're addressing the challenges present at the baseplate to heat-sink level. Removing the heat from a power module is important for ensuring interconnect reliability. Many thermal interface materials (TIMs) exhibit good performance at time zero. However, over time, thermal cycling takes its toll and many tin materials will either pump out or bake out under the active area, causing thermal runaway and failure. Some graphite-based materials may resist both pump and bake out, but they have poor thermal conductivity in the Z-direction, requiring larger X-Y geometry to help remove the heat.
    Indium Corporation offers a wide range of thermal interface materials that are pump-out, bake-out resistant and have superior Z direction thermal conductivity. For example, our Heat-Spring® is an interface that provides 86 watts per meter K of thermal conductivity using a pressure range of only 35 to 100 PSI. Heat-Spring® metallic thermal interface materials boast superior conductivity, ease of use, and improved performance over time as compared to thermal grease alternatives.
    In addition to metallic TIMs, Indium Corporations offers an HSMF compressible silicone-free material at thicknesses of 150 and 250 microns for heat-sinks with poor planarity. HSMF offers improved performance for a long-life reliability and, like Heat-Spring®, does not pump out or bake out over time.
    For more information on these and other materials for baseplate to heat sink, visit or, if you have any questions, feel free to contact me directly,