Issue link: https://iconnect007.uberflip.com/i/1398328
28 SMT007 MAGAZINE I AUGUST 2021 champions to keep it together, keep it sta- ble, and have a good cross-functional team to launch a product. Dack: I think that whole concept is underuti- lized, or not understood. I think we compart- mentalize too oen in corporations. e term "throwing it over the wall" stems from that. Vaughan: I would say that, in a perverse way, technology is driving us to communicate more effectively now because gone are the days of the standard eight- to 10-layer circuit board that many, many shops can fabricate. But more and more of the designs that we see certainly are 30+ layers, they have mixed materials, and there's five or six sequential laminations required; they're full of blind and buried vias, special features, and two- and two-and-a-half mil lines and spaces. ose are all challenges at the bare printed circuit board level. But then there are challenges that are also experi- enced at the EMS level, where there's a lot of very specific process parameters that they have to consider. Something as simple as new vias, for example. You've got to plate them, you've got to make them flat, you've got to do a lot of things, or if you just leave those vias in the thermals, of course that paste is going to slide through the holes and starve the pad of solder, and that's going to create solder balls, and on it goes. For every design decision that's made now, the implications at both the fabricator and the EMS provider are really unique and really chal- lenging. I think the OEMs know that. I see a lot more collaboration—willingness to collab- orate, have lengthy discussions, and overcom- municate—now in the current operating envi- ronment, if that makes sense. Johnson: You're describing what I've always called defensive design, where you anticipate the problems, anticipate the changes over time, and design to defend against them. Designing so that you could easily swap out a quad pack for a BGA, for example. It seems like more of that kind of forethought is now required. Is that true and how do we communicate that to designers? Dack: I have a term I coined and did a presen- tation on called "practical packaging density plus." Because we have practical packaging density, that gets us where we need to go. e tendency is to put too much bread in the bread- box. But if we can, from the concept stage— where the industrial designers are wielding their pastels on the whiteboard dreaming up a concept—add a little "plus" in there with regard to space, technology, materials, and availabil- ity, then that gives you the flexibility for future redesign. It's practical packaging density plus. I'll have to resurrect that idea for a future arti- cle soon. Johnson: anks gentlemen, for your time. Dack: Happy to help. Vaughan: I really enjoyed talking to everyone again. anks. SMT007 John Vaughan is vice president of strategic mar- kets at Summit Interconnect. Kelly Dack is a PCB designer, CID+, and an I-Connect007 columnist. To read his column, The Digital Layout click here.