Guest
What can possibly go wrong with a flex PCB design with hatched or meshed planes? You define trace width and spacing using an impedance calculator and route them straight over the hatched planes. Is that it? Maybe. Just to make sure that everything works as intended, load it into Simbeor SI Compliance Analyzer and run simulation-based ERC analysis as demonstrated in this short video (version with higher resolution is at ). You will literally see the impedance of the traces encoded with color - green is for the target impedance 50 Ohm single-ended or 100 differential in this case, blue is for lower and red is for higher impedance. All traces have same width and spacing, but why some traces are colored green and some look like a rainbow? This is the effect of the hatched reference plane. We can literally see that the position of the traces matter and this simple design can be substantially improved by properly positioning traces over the mesh. TDR, insertion and return losses can be also easily simulated in Simbeor with two more clicks as demonstrated here. Note that the accuracy of such analysis depend on the dielectric and conductor roughness models and manufacturing adjustments. See more on flex interconnects at and “design insights“ with the field views at #simbeor #electromagnetics #signal_integrity
