Durafuse® LT graphic showing the low temperature (blue) solder alloy fusing around and with the high melting (red) alloy to form a continuous solder joint
Being a recent addition to the PCBA (printed circuit board assembly) solder team at Indium Corporation, it has been eye opening to see how much change is possible in a field that from the outside might not seem to have as much going on.
One of the most exciting areas, which I am getting to see unfold before my very eyes is low temperature alloy development. Many of my coworker's blog posts are amazing resources for all the cool applications for low temperature technologies:
- Gallium - see Jim Hisert's blogs on cutting edge liquid metal technology
- Bismuth alloys - see Eric Bastow's video on neat bismuth properties
- Indium alloys! - see article helping with low temp solder selection
However, something really new that is coming out of Indium Corporation's R&D group is called Durafuse® LT - a method of combining the low melting temperature of indium-based alloys with the high reliability of a SAC alloy! Solder alloy development is a balancing act between desireable and undesireable properties for each application - and our research team does a great job of that. What our researchers discovered is that when the indium alloy starts melting well before the SAC alloy and fuses with the SAC alloy powder, it form a continuous metal joint that is both strong and durable.
Also for a bit of linguistic fun: The name Durafuse® LT is derived from Dura or Durable (Definition: able to withstand wear, pressure, or damage) and Fuse (Definition: to join or blend to form a single entity). This perfectly explains the alloy system in that it is fusing 2 different alloys together to form a durable and reliable low temperature solder joint that can withstand drop shock forces. It is also fusing the components to the circuit board in a lasting (or "durable") way, which is essentially the purpose of solder!