New Project Proposal New Project Proposal High Frequency Performance in Flexible and Flexi-Rigid Printed Wiring Boards Project Supporters: Arlon-MED (Rogers), Polar Instruments, Dupont Electronic Materials HDP User Group Member Meeting Irvine, CA March 11, 2015

© 2015 HDP User Group International, Inc. All rights reserved High Frequency Flex Project proposal Conduct a study to characterize the effect on signal integrity for flexible and flexi-rigid printed circuit boards operating at high end digital transmission frequencies with regards to: 1.Different design features 2.Material choices and 3.Operating environments The project specifics have yet to be defined but would likely involve the design, fabrication and electrical performance analysis of FPC test vehicles. Detailed objectives will be identified once a project team has been formed. 2

High Frequency Flex © 2015 HDP User Group International, Inc. All rights reserved Problem Statement Flexible printed circuits (FPCs) provide a practical option for interconnection of printed circuit boards and electronic modules, particularly where space is constrained or weight is a factor. Moreover FPC construction offers greater levels of impedance control compared with co-axial and other wired connections. However with FPCs increasingly being used in high speed digital applications, understanding their electrical performance at high frequencies becomes a growing challenge. Several issues arise from using them for this purpose. 1.Controlling the geometries of flexible materials as they differ from rigid PWBs. 2.The differing properties of the materials (Dk, Df etc.) involved and the fact that some dielectrics and adhesives are very hygroscopic. 3.Cross hatch GND planes. Simulating the effect of the non-contiguous plane and the effect of various shapes. 4.The use of Tatsuta shielding and other shielding approaches like metalized films. Used as an EMI shield in many applications but has effect on the signal integrity of the transmission line. 3

High Frequency Flex © 2015 HDP User Group International, Inc. All rights reserved Potential Project Partners Input is welcome from both HDP User Group members and companies outside the organization who can contribute. In particular it is envisaged that designers, fabricators, relevant materials suppliers and test houses/test equipment providers would be desirable for the project to deliver maximum benefit. Contact : John Davignon, HDP Project Facilitator at 4