Issue link: https://iconnect007.uberflip.com/i/1307491
12 DESIGN007 MAGAZINE I NOVEMBER 2020 Feature Interview by the I-Connect007 Editorial Team Andy Shaughnessy and Happy Holden speak with Stephen Chavez, a staff engineer with an aerospace company and chairman of the Printed Circuit Engineering Association (PCEA), about designing vias for greater reli- ability. They also address several areas where they can look to improve reliability, a variety of steps that designers should take to help ensure more robust vias, and some testing and educa- tional resources that PCB designers and design engineers should be aware of. Andy Shaughnessy: Welcome, gentlemen. Com- panies keep having problems with vias. Some OEMs will send out a dozen test boards with different-sized vias to a dozen different fabri- cators, and they'll come back built a dozen dif- ferent ways. What can the designers do? What are your thoughts on via design for reliability? Stephen Chavez: My initial thought on this is that at the earliest stages of the design cycle, communication with your suppliers is an extremely important part of your overall PCB design success. Collaborating with your sup- plier to lock in your PCB stackup is also a vital step in the early stages of your design. This leads to solidifying your constraints before parts are placed and any traces are routed, which includes the types of via technology that will be implemented in the design. By collabo- rating with your suppliers and applying indus- try best practices for PCB design, the odds of achieving a robust, high-reliability DFM design is very good. As today's printed circuit engineers strive to meet today's challenges, there are three com- peting perspectives for success when design- ing PCBs: design for layout solvability (DFS); design for performance (DFP), meaning SI/ EMC, power delivery, and thermal; and design for manufacturability (DFM). In the end, the main goal is to get it right the first time. Make Revision 1 work by maximum placement and routing density, optimum electrical perfor- mance, and efficient, defect‐free manufactur- ing to achieve high yield and lower cost. When I talk about meeting today's chal- lenges when designing multilayer PCBs while keeping in mind the three competing perspec- tives for success, the via strategy and quality Stephen Chavez and Happy Holden on Designing Reliable Vias