Trouble in Your Tank: Via Hole Filling and Plugging, Part 2
In my previous column, I presented several options with which to accomplish blind and through-hole via filling. In this edition of “Trouble in Your Tank,” I will discuss filling blind vias and through-holes with polymeric pastes.
Via Fill Paste
Often, the phrase “plugging paste” is used to describe the method and material of completely filling blind vias and through-holes. In general, paste filling material selection is at the request of the end user and indicated for a number of reasons. It has been my experience that major OEMs are driving the industry to migrate to the high-Tg/low-CTE plugging paste formulations for high-density applications. In addition, these formulations are of a non-conductive nature that provides a high-quality plugged via that is cost-effective. Limitations abound depending on PCB thickness, via diameter, and paste properties.
To read this entire column, which appeared in the October issue of PCB007 Magazine, click here.