Issue link: https://iconnect007.uberflip.com/i/1467744
66 PCB007 MAGAZINE I MAY 2022 thing to achieve an electrical performance tar- get by itself. It's not as easy to get the electri- cal performance and satisfy everything else the material has to do. In addition to meet- ing signal integrity requirements, the mate- rial also needs to meet thermal reliability and CAF resistance requirements in complex, high-layer-count boards. We also focus on PCB manufacturability. We want our prod- ucts to be as easy to use in PCB manufacturing as possible so that our customers can achieve high yields. So we spend a lot of time up front developing resin systems and integrating them with glass and copper options to meet all these requirements. Back to electrical performance, we also have to consider how materials are used by the PCB fabricator. It's important to recognize the nuances of keeping the system as low loss as possible. When the fabricator takes our mate- rial, makes an innerlayer circuit, and runs it through oxide-alternative chemistries, that's another area of attention for 5G signal integrity performance. If you roughen up the copper surface too much, you degrade the loss perfor- mance. We're all working as hard as possible to make sure the end product achieves the goals of the OEMs. Johnson: at's a lot to balance those constraints. You're already work- ing iteratively on known solutions, so how do we develop materials that help open a more reliable high- speed 5G application? Kelley: We're about to release a new product called TerraGreen 400G. As the name implies, it's extremely low loss and halogen-free. We've got our UL certification. We're focused not just on the performance of the mate- rial itself, but whether we can man- ufacture it repeatably day in, day out. As the product grows, is the supply chain stable enough to sup- port demand growth? We are wrap- ping up some of the final qualifica- tion testing, not just to meet internal require- ments, but with suppliers; we want to make sure we have a robust supply of the materi- als that go into it. Our goal with the product, with the combination of resin, glass, and cop- per, is 25% lower loss than our best performing high-speed digital product currently, which is Tachyon 100G. With the combination of resin, glass and copper, we're hitting those signal integrity tar- gets with this product. We've done the thermal SG Lab Press—new R&D scale press system in Isola's Singapore lab. Example of one type of equipment used for measuring Dk/Df of base materials.