Issue link: https://iconnect007.uberflip.com/i/1500943
12 DESIGN007 MAGAZINE I JUNE 2023 be weekly, but the customer should not be le guessing where things are, and the designer shouldn't get too far ahead of customer review. What issue do you think PCB designers should be more aware of? e ever-changing technology of the end man- ufacturers, especially of fabricators. It is easy for designers to get caught up on "standard best practices" or "rules of thumb." It is also common for designers to not always know the capabilities of who will be doing the manufac- turing, so they necessarily (or hopefully) are more conservative in their layouts. Fabrication tolerances and practices don't always just get tighter and more advanced. e back and forth I've seen on stacked and staggered vias is one example. oughts continue to change on reli- ability of stacked microvias and each vendor or manufacturing expert will have a different opinion. I think PCB designers should be diligent in pushing to get up-to-date manufacturing capa- bilities from the planned end-fabricator for each project. It may be them, a project man- ager, or the customer requesting the informa- tion, but taking the time, especially for more complex projects, is critical. Nothing is worse than finding out in DFM, aer a six-month lay- out effort, that you need to increase your annu- lar ring size or trace spacing in a dense high- speed design. e information listed on vendor websites or capabilities documents is oen not sufficient to make design decisions on multi- lamination cycle and high-density boards. It is important to have that conversation early and not make assumptions. What problem should PCB designers be more aware of? Not consciously identifying the key limiting factors for a design before diving into place- ment or routing. Design is a balance of many requirements, oen competing ones. Taking the time to be intentional and to really think through all the factors that will govern a design is key. For example, power and signal integrity or RF requirements oen conflict and tradeoffs need to be decided. Designers all too oen incorrectly assume what the priority might be or, even more oen, only hear partial feedback from the constituents rather than gathering all the requirements and ensuring the customer internally works through prioritization. Fab- rication requirements and electrical design specifications may be very different. Yet these competing requirements may all govern the same signals or, even more typically, the same signals may cross through regions of the board with different requirements. How you make decisions when planning your placement and routing, especially on dense, high speed, or highly constrained boards, will make all the difference in how challenging it is to route and how well it will function. Pesky late-breaking mechanical requirements, such as a mounting hole in the middle of where you placed your ASIC or keep-outs you didn't know were needed, can be devasting near the end of the design process. Layout kickoff checklists can be a great way to make sure you don't miss important questions that will drive your design. Ironically, this too comes back to good communication. Cherie Litson Litson1 Consulting What is your main concern for PCB designers? In a word: DFX. Actually, that's an acronym with a lot of baggage. But it's true that every tradeoff a designer makes, every decision a design team makes, changes the efficiency of the production and workability of the product. What issue should PCB designers be more aware of? Power and GND returns. ese are the main sources of a noisy circuit. Placing components