Brandon Judd and I have been working on a paper for this year’s SMTAI event, and I thought I would share a snip from it. Although people generally share the beginning of a paper, I’d like to share the conclusion, in
“With the miniaturization of today’s electronic devices and the increasing complexity of their features, the need for PoP components is significantly increasing. Although it may seem like a simple solution to just use the standard SMT paste that you have in-house for your upcoming PoP applications, these products will not be optimal for this type of process. As our testing has shown, modern PoP solder paste materials are much better suited to the dipping process used for PoP components. Formulation, particle size, and metal loading are all key factors in the design of a PoP specific paste. The time spent evaluating these new products is well worth saving yourself the headaches of getting electrical opens on your boards from using standard SMT materials or even outdated dipping pastes, causing costly and time consuming rework down the road. With the proper material and process, insufficient solder transfer and head-in-pillow defects should be a thing of the past. “