Issue link: https://iconnect007.uberflip.com/i/1153097
AUGUST 2019 I DESIGN007 MAGAZINE 95 Creeden: That gets back to my original thought about the designer's triangle of three perspec- tives to look at everything in layout. There's a solvability that with that cable, you're going to replace it with something that is much smaller. You're saying it will typically out-perform be- cause you don't have all the parasitics that the actual pad, cable, and solder have and brings about in that connector. Hunrath: You save weight. You increase perfor- mance, and often, you can save costs too. Creeden: Regarding removing connectors, what can I expect would be one of the challenges in moving away from a connector, and going to a flex? Bowles: From a design perspective, I'm not sure, but everybody fabricates flex, right? Some people build rigid-flex or try to build a rigid- flex in their traditional rigid shop or vice versa. They might be a traditional flex shop, and now you're trying to have them build a rigid-flex de - sign. There's a learning curve with the differ- ence in materials there, but I don't know from a design perspective. Hunrath: From a design perspective, there are "do's and don'ts" in flex. If you're going from a cable system—from connector to connector to a pure flex or even a rigid-flex—you don't do things like I-beam circuits, right? You want to make sure that the circuits on both sides of your double-sided flex are offset to improve flex life and flex performance. You have bet- ter flexibility and better flex life. Again, a lot of this stuff is well understood; we have that information, and we want to share it and pro- mote it. But that would be one example; if good data on those design characteristics, and I would encourage someone doing a design if they need that to reach out to Insulectro or Du- Pont. At Insulectro, we'll get you in touch with the right people if we don't have the data in hand, but DuPont has people who have exper- tise in those areas. Creeden: A lot of times, the fabricator is going to build it in their supply chain. When should they be contacting them? Hunrath: Ideally, the earlier, the better because you don't want your design to be backtracked. The earlier that the designer gets the informa- tion they need to solve some of these issues, or to meet the performance requirements, the better off everyone is. Creeden: Right. Steve, what's driving some of your customers into flex right now? Bowles: Higher speeds, higher frequencies, and smaller devices. Creeden: Smaller devices in overall housing? Bowles: In every axis possible. We have cus- tomers coming to us, saying, "We have an ex- isting design where we want to reduce the Z, and the total overall stackup thickness needs to be cut in half." With our materials, the films themselves are relatively thin, and we can throw thin copper weights on them too; we can also build a much thinner stack of the flex. There are some thin rigid materials as well, but that's one area that the flex performs for us. Further, we can build and accommodate spe- cific designs that have a lot of bends and kinks in them. Hunrath: DuPont has a cable and a correspond- ing flex with the same circuitry and the weight and the performance. That's one of the things you could see at this Innovation Center: the difference between a cable system, or a cable harness, and a flex circuit that replaces that same cable harness. You'd see that there's a huge difference in the fit. You save weight. You increase performance, and often, you can save costs too.