Issue link: https://iconnect007.uberflip.com/i/981887
14 DESIGN007 MAGAZINE I MAY 2018 that you have challenges with copper bond and peel strength. With the millimeter wave, you certainly start to foresee more material challenges than you see at lower frequencies. Jordan: I think this really does tie into the CAD side as well, because if someone doesn't have a lot of experience and knowledge, we always say, "Work with your fabricator." A lot of fab- ricators are going to struggle with this stuff, and there will be a few leading-edge ones, and it might be more suit- able for people working on 5G apps and design to work more with the materials com- pany first than with the fabri- cator. I can foresee that we're going to need improved capa- bilities in layer stack plan- ning, and maybe even some kind of simulation capabil- ity for things more around the mechanical limitations of layer stacks. People already do thermal analysis on their circuit board designs, they do impedance control calculations and use 2D and 3D field solvers to make sure their layer stack is going to function as desired at RF and high- speed digital edge rates. But there's going to be an increasing number of people who have a great idea but don't know the mathematics or analysis techniques behind getting something to work with an appropriate layer stack that's affordable to manufacture. With all those tradeoffs, on the CAD side, we need to introduce capabilities in layer stack planning that will help people making those tradeoffs and reuse known good layer stacks. Maybe it would be good for us to partner with a company like Rogers and come up with sample layer stacks that people can reuse. You know, if you build it this way, specify it this way, you'll have an easier time getting your design to pro- duction. Hendricks: Sure. At Rogers, we have a two- pronged approach. We historically have very good and close links with microwave and RF engineers who tend to be the material speci- fiers at the higher frequency side of things. But going forward, because of the increased complexity of the boards, we also have a very strong technical service team that works very closely with PCB manufacturers and partners with them to help with design and the process- ing technologies. It becomes a triangle between the electrical designers, the manufacturers, and the mate- rial suppliers. We effectively have to work together. Jordan: Collaboration is really the name of the game, isn't it? Hendricks: Yup. Patty Goldman: How often does that collaboration hap- pen? Hendricks: There's often this old-fashioned traditional approach where the electrical designer designs a PCB and then goes to a PCB manufacturer and the PCB manufacturer says, "I wouldn't have designed it that way." I guess there's always an element of that in it. We don't often have three-way partners or three-way meetings, but there is a set of three-way communications. We talk closely to the PCB manufacturers and the OEMs equally, basically. Goldman: I asked that because we hear that so often on all sorts of different subjects that "if only they could let us know first and we could all work together it would be so much better." Hendricks: Yeah. It never goes completely smoothly (laughs). Stephen Las Marias: Do you think these 5G challenges will have an impact on the PCB assembly side? Ben Jordan