I have a customer who is asking for 60-90 Ohms (single ended) on a card bus PCB that has the same parameters as a 6 lyr PCMCIA at .020 thk max. The specified trace requirements also recommend a prop delay of 150-190 ps/In (Tpd). Modeling this little jewel leads one into PTFE type Er. However, the Tpd drops below recommendations. Using FR-4 type materials drops the linewidth down into micro miniature ranges. Has anybody else encountered such a requirement? Is this a realistic requirement? Any and all replies will be greatly appreciated. Dave Hoover (Groovy) *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************