Issue link: https://iconnect007.uberflip.com/i/1284035
114 SMT007 MAGAZINE I SEPTEMBER 2020 Edited by Happy Holden I-CONNECT007 On the first day of the IPC High-Reliability Forum, Denny Fritz gave a presentation on weak microvia interface and stacked microvia reliability. Denny Fritz was a 20-year direct employee of MacDermid Inc. and is a retired engineer after 12 years as a senior engineer at SAIC, supporting the Naval Surface Warfare Center in Crane, Indiana. He was elected to the IPC Hall of Fame in 2012 and is now the head of the Hall of Fame Council of Fellows. Denny has also been involved with the weak microvia team for a couple of years and has participated in many technology roadmaps, better compo- nent activities, and standards for board fabri- cation—particularly Pb-free Electronics Risk Management (PERM). Currently, he is presi- dent of Fritz Consulting, as well as an I-Con- nect007 columnist who writes "Defense Speak Interpreted" on military and defense industry topics and applications. Here, I have assembled the highlights of Denny's presentation, including the transcript, which has been slightly edited for clarity. Today's Purpose Tomorrow We certainly do not want to scare away any new designers. Microvias remain a reliable interconnection construction as long as you do things according to IPC test methods and observe practices that will come out in the pre- sentations. However, we do want to alert you to a reliability issue that has been around for a couple of years publicly and maybe as many as 10 years. From some of the stories we've heard, many people thought that they were the only ones who had this problem until they compared notes with other companies that fabricate and use microvias. We are trying to find the root causes of the phenomenon, and we would certainly like any data that you can contribute. If you are not willing to contribute data, please support the working effort of our IPC teams. Where we stand today is to mitigate this microvia problem through design parame- ters, etc. The Weak Microvia Team is not here to specify product acceptance test methods but to work on the problem itself, so you'll get plenty of information in the presentations on the test methods. Our objective is to give you a background on the problem, understand the causes, and help guide the efforts of individual companies and consortiums to find answers. This will give you an idea of the teams that are under the Weak Microvia Group, especially because this is on a test program that IPC is participating with IMEC and ESA. Certainly, the overview explains how to pre- vent escapes from the fabrication process by understanding the capacity and yield impacts Denny Fritz Unpacks Weak Interface and Stacked Microvia Reliability Denny Fritz