We evaluated and approved KESTER R520A for our default RoHS solder paste a couple years back. It's time to re-evaluate to see if this material is still the best choice. Please let me know your opinion on the solder paste you are using, and your average application.
Our facility builds mostly double sided low volume high mix. Usually significant qty of BGA, Micro BGA, 0402's. With the high mix we sometimes have prototype qty boards, post screen longer than we would like prior to reflow. I have no problem using a different paste in those situations vs our higher volume.