Issue link: https://iconnect007.uberflip.com/i/1361971
66 PCB007 MAGAZINE I APRIL 2021 tric properties. Epoxy is good, but this material is better. Rap- id charging drives this heavy copper requirement as well as the ability to make circuits and embed them in the dielectric material. With thermal per- formance, in the organic sub- strates, it has always been the domain of polyimide, with ep- oxies, multifunctional epox- ies, and some materials in be- tween. But there was a space between polyimide and epoxy, and we knew that polyimide doesn't do certain things very well. It absorbs moisture, but it gets brittle as it cures. It is very decomposition resistant, but it does have some other drawbacks. As Michael mentioned, ceramics are very good in certain applications for high tempera- ture, but you can't do everything you want to do in circuitry in ceramics that you can easily do with a PCB material or organic PCB mate- rial. is just gives the engineers and design- ers a whole lot of options when they're design- ing circuits. e base resin chemistry (I don't believe it's proprietary) is something called benzoxazine, and it's a newer resin system. It's been around for a long time, but it's newer than epoxy. e way it cross-links and the way it be- haves in high temperature applications is dif- ferent. It has actually been used in aircra bod- ies. You've heard the airline industry is moving away from aluminum parts to composite parts. Well, this is the resin that is being used. Res- in has to be able to flow and fill large features very well, but it also has to withstand tempera- ture variations. ink of an aircra on the run- way vs. an aircra in the upper atmosphere— we see some pretty wide temperature chang- es. is resin chemistry does all those things very well. Johnson: If it's being used for exterior air- cra parts, that indicates it is resistant to UV. Plus, it's good with rapid tem- perature variations. It's good with humidity issues. Hunrath: It's good with frac- ture toughness. Gay: Yes, fracture toughness is a big deal. Johnson: Right. And that fits with what the automotive in- dustry has been asking for. You can't necessarily put standard FR-4 into a vehicle that might go to either an Arctic region or a tropical region. Hunrath: Yes, and this is intended for the elec- tronics, the battery structure, the charging sys- tems, and those types of things. Johnson: How appropriate is benzoxazine for miniaturization? Does it play well on the sen- sor side, or is this primarily the powertrain? Gay: It's primarily designed for power distribu- tion and the systems that connect the automobile to the charging stations, and then distribution within the automobile. In the charging arena, we're going from lower voltages to much higher voltages. e material has to be able to withstand those voltages across tight spacing. You have the hole wall-to-hole wall spacing, and it needs to be able to manage both that and Z-axis spacing. You can't build a board that's two inches thick; you have to build a thin board, so Z-axis capability on thin dielectric is really important. is is where this particular material excels. Johnson: Do you see IS550H having applica- tion in the infrastructure and charging distri- bution portion of the network? Gay: Yes, there are definitely opportunities in the distribution network. We've seen applica- Chris Hunrath