High Frequency Flex Project Definition Phase Project Lead: TBD Project Facilitator: John Davignon, HDPUG HDP User Group Member Meeting Santa Clara, CA Feb 10-11, 2016

Problem Statement © 2015 HDP User Group International, Inc. All rights reserved Flexible printed circuits (FPCs) provide a practical option for interconnection of printed circuit boards and electronic modules. 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. Differences between measured results and present models have been seen. Several issues arise from using them for this purpose. 1.Controlling the critical 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. Cross hatch GND Planes used for Flexibility & Impedance control 2

© 2015 HDP User Group International, Inc. All rights reserved Project Proposal/Scope Of the three areas of concern the team has decided to conduct a study to characterize the effect on signal integrity for flexible printed circuit boards operating at high end digital transmission frequencies with regards to: Different design features: Various Crosshatched ground plane designs Material choice: Polyimide (DuPont/Panasonic) Laminate thickness: 100 um Frequency ranges up to 20 Ghz S parameter performance analysis (Insertion & Return Loss and Impedance) of FPC test vehicles Comparison of measured results vs. models 3

DOE/Objectives © 2015 HDP User Group International, Inc. All rights reserved 4 Design a test vehicle using a Solid Plane as the reference feature and various cross hatch designs. Run with a series of frequencies up to 20 GHz and see the effect on impedance/loss. Would need TDR and S parameters. Evaluate how the cross hatch designs effects impedance and S parameters (insertion and return loss) Overlay the response on a plot and evaluate how much they are different or change. Compare model to measured results

Deliverables © 2015 HDP User Group International, Inc. All rights reserved5 Publish a comparison of measured SI data to present model predictions Publish guidelines on crosshatch design findings Publish final report to members Present finding at industry conference (EIPC/IPC APEX) Recommendation for the next phase of work

Benefits © 2015 HDP User Group International, Inc. All rights reserved 6 This project will provide the industry with the fundamental knowledge of the mechanical/design and electrical properties differences between flex and rigid products. Provide important knowledge of why the present models do not match the performance being measured. Provide better methods to design with flex going forward. Provide an understanding of the effects of crosshatching design and how to improve the design.

Status © 2015 HDP User Group International, Inc. All rights reserved 7 Team focused on replacing Project Lead and loss of Polar Instruments Flex Laminate Materials and thickness have been decided Frequency test range has been decided Coupon designs are underway Project still open to new participants and presently seeking project resources CAD Designer help for coupon/layout (Ciena) Additional Flex Fabricator Additional test house (SPP - Introbotix) 3D simulation capabilities

TV Stack-up © 2015 HDP User Group International, Inc. All rights reserved8

Flow Chart © 2015 HDP User Group International, Inc. All rights reserved9 Materials Hatched Plane TV Design Fabricate TV Test Select Laminate Materials Procure Materials Panasonic DuPont Impedance Loss – DuPont/Introbotix Design TV w/ Gerber files M-Flex Fabricator(s) TTM DOE Definition Downselect Objective/Goals 3D Simulations –MFlex 2D Simulations - TBD Finalize Test coupon designs DuPont/ Ciena Analyze Data DuPont/Nokia Analyze Data DuPont/Nokia Write Report TBD Write Report TBD Present Report Close Project

Resource & Schedule © 2015 HDP User Group International, Inc. All rights reserved10 TaskOwnerPlanned Schedule Actual Schedule DOE DefinitionPolarQ4’ 15Completed Design TV couponsPolarQ4’ 15In-progress Generate Gerber/Design Files M-Flex / CienaQ1’ 16 Procure TV laminateDuPont / Panasonic Q1’16 Fabricate TVTTMQ2’16 Test - Measure Coupons DuPont / Introbotix Q3’16 Analyze Data / Compare Si to Models DuPont / Nokia- US Q3’16 Write ReportTeamQ4’16 Present / Publish Findings TeamQ4’16

Project Participants © 2015 HDP User Group International, Inc. All rights reserved11 DuPont Engent IBM M-Flex –Non-Member MicroConnex – Non-Member Nokia-US Panasonic Rogers TTM

High Frequency Flex © 2015 HDP User Group International, Inc. All rights reserved Potential Project Partners Input is still welcome from HDP User Group members who can contribute. In particular, a CAD designer, additional Flex fabricator and test houses/test equipment providers would be desirable for the project to deliver maximum benefit. Contact : John Davignon, HDP Project Facilitator at 12