Issue link: https://iconnect007.uberflip.com/i/1467744
68 PCB007 MAGAZINE I MAY 2022 of performance. How does a material supplier have that conversation with the designer and fabricator? Kelley: For many years, I was a printed cir- cuit board engineering guy, so I've been on both sides of the fence. It used to be that the material supplier talked to the fabricator, and the fabricator talked to the OEM—but that changed. Material suppliers began talking to OEMs and convincing them to specify their material, sometimes to the dismay of the PCB fabricator. Johnson: Because the fabricator must certify something. Kelley: ey might even tell the fabricator, "You're going to use this product." As a former fabricator, I never liked that either. We prefer to work collaboratively with both the fabrica- tor and OEM, particularly on new products or new programs. As much as our customers will allow, Isola tries to have the conversation with both the fabricator and OEM together. at's the general trend. For example, with Ter- raGreen 400G, we regularly have simultaneous calls with fabricators and OEMs. On the OEM side there are those who are in charge of qual- ifying materials, and oen designers or sup- ply chain people, as well as fabrica- tor representatives. We're all on the same call, hearing the same things, and marching to the beat of the same drummer to make sure we're all aligned. When you look at 5G and these next generation materials, it will be even more important because with small variations in our process and the fabricator's process, signal integ- rity can be affected. For example, oxide alternative chemistries play a significant role in loss performance. Maybe we pull in the chemistry sup- pliers as well. It's more complicated, but there is value in everyone working together. You test something once or twice and get a cer- tain performance level, but how do you know you'll get that every day? It worries me. On our side, we implemented a stage gate development process a few years ago, and we're always refining and improving that pro- cess. We want to test the boundaries of our process. For example, if a resin is at the end of its shelf life, what does that mean for the per- formance of our product in our customer's hands? Is the Tg lower? Does it affect loss per- formance? We want to understand these fac- tors before we fully commercialize a product. Johnson: I understand certification takes some time to complete. Kelley: Yes, and that's the challenge with the stage-gate development process. It's more accurate to say we use a modified stage-gate process, because we are doing as many things as we can in parallel. Even when we're testing formulations at a lab scale, we have to under- stand how it's going to react in a printed circuit board structure. So very early on we're build- ing thermal reliability, CAF, signal integrity, and other test vehicles to understand and test those boundaries—not just related to the resin formulation but processing as well. When the The Isola QTA and R&D facility in Chandler, Arizona.