Indium Blog

Why is AuSn powder size important for solder paste application?

  • AuSn
  • Gold Solder
  • Solder Paste

  • Today’s electronics continue to get smaller and smaller, so the traditional type 3 (-200/+325) mesh size might be too large for new scale-ups. It is not uncommon for AuSn solder paste to be used in R&D applications for scale-up and then converted to AuSn solder preforms in production. Most AuSn solder preform applications for sealing and die-attach are 0.001” thick or less. The particles in type 3 are in a range of 0.001” -  0.0018” thick.

    We offer particle sizes down to type 7 (2-11µm particle size) for dispensing smaller deposits for smaller apertures. this can allow for thinner bondlines to mimic solder preform applications. Particle size is also important role when determining the size of the dispensing needle for solder paste.

    Here’s an overview particle sizes offered for 80Au20Sn powder for solder paste:

    If you are interested in learning more about Indium Corporation's AuSn solder paste, or want to discuss your application, please email me at