Martyn Gaudion, CEO, Polar Instruments, explains; “Flex and Rigid flex designers and fabricators have long asked for additional field solver capability to enable modeling of PCB transmission lines with meshed or crosshatched ground return planes. XFE is an extension to the Polar Si8000m and Si9000e which enables the rapid modeling of lossless transmission lines with this type of ground return structure. This is a long awaited enhancement for the flex and flex-rigid community, which will also benefit other PCBs where crosshatching is deployed in order to keep impedance controlled line widths at reasonably manufacturable geometries – as for example on interposers.”
XFE employs Polar’s proprietary multipass 2d boundary element field solving technology to model the impedance of transmission lines with crosshatched return planes. Modeling from 10% to 100% copper returns on impedance tracks is now as simple to implement as traditional impedance controlled structures. The broader geometrical variations of flex base materials compared with rigid materials mean it is even more important to model the correct design dimensions in order to reduce the amount of prototype turns needed to guarantee yields.