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ideas. RF engineers are oen very hesitant to make changes. We see this much more in RF than in digital. Once you have a certain type of design that works, you don't want to change it, because it's oen hard to model and figure out exactly what will happen when you change it. at has led to less adoption of newer PTFE technologies at times. As a result, you have RF designers still work- ing with older materials. I can get a lot better dimensional stability out of a highly ceramic- filled material than I can get out of a nearly pure PTFE. It's the same with the plating situ- ation. We have fewer requirements for activa- tion when you look at a hole wall and it's 85% or 90% ceramic. It's not as big a concern. Of course, it's also a different dielectric constant. So, when you change the permittivity, it limits the ability to address some applications. What are you looking for with new materials? When we look at new materials, we're focused on controlled dielectric thermoset materials because, honestly, there's not a lot of them out there. If you're pulling out of high-speed digital and working with materials designed around high-speed digital, they're not con- trolled dielectric construction. e resin con- tent changes depending on the construction. When you go to a digital designer, they want availability of every half-mil increment, but you can't maintain controlled dielectric that way. From an RF standpoint, we're looking to take some of those resins and make slight mod- ifications of those resins to create controlled dialectic constant materials. Are we getting to the PTFE level of Df ? No, but we're getting to what I would consider the mid-loss PTFE level, something less than .002 Df, maybe .0015 or .0017 range. e focus right now is on resins that are much more stable than some of the older thermosets, so you have very good thermal characteristics. at's the direc- tion I think that the industry will go because of the complex RF design needs. Resins have improved to the point that some designers are doing RF with traditional lami- nates, and just bypassing the RF laminates. Oh, sure. We're even doing anten- nas on polyimides and FR-4. It comes down to RF designers understanding which material they can get away with. at's part of our approach—to educate them on what you can do with these differ- ent materials, and what they need to think about. We don't see the end-result of every application, but we've been around enough of these applications that we know what you'll need. What are some of the mistakes that RF designers typically make? As we move into more thermo- set materials, the biggest mistake is thinking, "I want this dielec- tric thickness." I get that. If you've 58 DESIGN007 MAGAZINE I APRIL 2025