Fine Pitch Reliability Comparisons Between Components Assembled On Motherboards Containing Filled Or Unfilled Microvia-In-Pad
Authors: Michael Meilunas and Martin Anselm, Ph.D. Company: Universal Instruments Corporation Date Published: 10/13/2013
Abstract: Fine pitch surface mount devices typically require printed circuit boards containing microvia-in-pad for complete route-out. Frequently the microvias are left open: a design feature which reduces the solderable land area while possibly increasing solder joint voiding. This research was designed to evaluate the potential effects of the open microvia design on the relative reliability of 0.3mm to 0.5mm pitch devices subjected to drop testing and accelerated thermal cycling. The results were compared to similar test vehicles assembled on motherboards containing copper filled microvia-in-pad. The experiment suggests that the open via may have application specific advantages and disadvantages when compared to the copper filled via, and a knowledge of these benefits and detriments may prove useful during a product’s design phase.