I had a call with a few engineers today who wanted me to answer a question, “Which solder paste do I pick for my application.” Sure there were a few application-specific details that I feel were too specific to discuss with a general audience, but I think I can answer the question for any of you that are out there wondering the same question while reading this.
It’s an easy answer really; start with SR-8 unless:
1) You are using laser reflow equipment.
2) You have noticed solder spatter issues related to your design.
3) Your company or end customers require you to use only halogen-free materials
4) The residue must be clear and almost non-existent (ultra-low residue levels)
If you said “yes” to any of the above, you’ll want to try SR-7 (as long as you have nitrogen reflow capability). If you said yes to answer 3 (halogen-free) but you do not have nitrogen reflow capability, try SR-089.
Jim’s note: This post was written in August 2010 – but it will be available to anyone searching for the info for quite some time. For updated information on newer solder pastes, send an email to Solar@Indium.com. Thanks! ~Jim