Controlled Impedance on High-Speed Flex PCBs
By ZM Peterson • Dec 18, 2024Flex PCBs can support controlled impedance routing normally found in high-speed PCB design thanks to a hatched ground plane.
Meet Your
Signal Integrity Experts
Data rates and required channel bandwidths in modern electronics are only going one direction: up! That's why signal integrity in digital and RF designs continues to become more important in a range of products. Today's digital processors are fast enough that just about every PCB must incorporate best practices for signal integrity. As designs get more advanced, the depth of signal integrity analysis and simulation only increases. This is why advanced electronics companies collaborate with NWES to solve their toughest signal integrity challenges and improve their designs.
- Learn more about signal integrity analysis.
Our Capabilities
Ensuring Signal Integrity in PCBs and Substrates
In high‑speed PCB and substrate systems, signal integrity issues go far beyond simple reflections or crosstalk; challenges include frequency‑dependent dielectric loss, inter‑symbol interference (ISI), substrate parasitic coupling, power plane resonances introducing jitter, and dielectric anisotropy affecting impedance and propagation velocity. Our services integrate EM modeling, channel analysis, and eye diagram simulations to assess signal behavior from the substrate to the PCB, addressing performance defects before fabrication.
Signal impairment often stems from nuanced physical factors: dielectric loss in high‑bandwidth channels; coupling via shared dielectric layers; impedance shifts in anisotropic multilayer PCB stackups; and PDN resonances that degrade timing and increase bit error rates. We provide stackup and material validation, signal integrity analysis in both time and frequency domains, and calibrated eye‑mask evaluation across board and substrate layers. This enables precision tuning of design parameters, improving waveform fidelity, timing margin, and interconnect resilience in demanding high‑speed systems.
Signal Integrity Software Support
Signal Integrity Verification with Simbeor
Fast analysis and full 3D electromagnetic simulation of PCB interconnects for standardized interfaces, such as PCIe, USB, DDR, and Ethernet.
- Impedance Control & Transmission Line Optimization – Accurate modeling and validation of PCB trace impedance to minimize signal distortion.
- Loss and Dispersion Analysis – Characterization of conductor and dielectric losses to enhance signal quality in high-speed interconnects.
- Crosstalk & Reflection Mitigation – Analysis and reduction of unwanted noise and signal integrity issues in dense PCB layouts.
- Material & Stackup Optimization – Selection of optimal PCB materials and layer configurations to meet high-speed design requirements.
Ansys HFSS & SIwave
System-level EM and PI/SI solvers for PCB interconnects, IC substrates, and chip-to-board signal integrity and power delivery.
- 3D Interconnect and Connector Modeling – Extract broadband S-parameters for transmission lines, vias, breakouts, and connectors.
- Channel Compliance – Validate high-speed digital channels, including crosstalk, mode conversion, equalization, and conductor roughness.
- PDN Resonance & Decoupling Optimization – Identify anti-resonances, place capacitors, and shape planes for low Z(f).
- PCB and IC Substrate Support – Ideal for high-frequency PCBs and IC substrate designs targeting the highest data rates.
Polar Si9000 & Speedstack
Paired field-solver and stackup planning to achieve controlled impedance with reliable manufacturability at the beginning of a new design.
- Controlled-Impedance Modeling – Predict single-ended and differential microstrip/stripline across build options.
- Stackup Development – Define layer counts, dielectrics, and cores/prepregs aligned with fabricator capabilities.
- Material Selection and Loss Planning – Compare laminates and copper roughness to hit insertion loss targets.
- Fabricator Co-Design – Analyze etch/press tolerances and document stackups for repeatable production.
CST Microwave Studio
High-frequency 3D EM analysis for complex geometries, enclosures, high-speed digital designs, and RF designs.
- Broadband S-Parameter Extraction – Time/frequency-domain solvers for fast design exploration and validation.
- RF Design Analysis & Optimization – Analyze RF circuits, optimize antennas, and tune matching networks for performance.
- Cavity & Enclosure Effects – Evaluate slots, shields, cavities, and apertures that impact RF performance.
- 3D Interconnect Designs – Model vias, connectors, and breakouts with broadband accuracy to ensure signal integrity.
OpenEMS
Open-source time-domain and frequency-domain solver for any 3D geometry with tools for rapid validation of digital and RF designs.
- Parametric & Scripted Studies – Sweep geometries/materials with programmable workflows.
- Custom Fixtures & Test Structures – Prototype coupons and fixtures for correlation with lab results.
- Optimization & DOE – Explore design spaces with automated runs and objective metrics.
- Cross-Validation – Correlate results against commercial solvers to increase confidence.
Signal Integrity Metrics Review
Before moving to fabrication, a detailed review of SI-related metrics provides crucial insight into channel performance; we help you quantify integrity risks and drive confident design decisions.
- Impedance Profile - Extract true characteristic impedance curve to determine appropriate width compensation and impact of conductor roughness/plating.
- Channel Bandwidth - Evaluate whether the channel supports the minimum required bandwidth for the target data rate.
- Insertion Loss and Return Loss (S-parameters) - Measure signal amplitude loss (S21) and reflections from impedance mismatch (S11).
- Crosstalk and Mode Conversion - Assess near-end and far-end coupling between adjacent traces.
- Compliance Metrics - Analyze eye opening, jitter, ringing, inter-symbol interference (ISI), COM, and BER timing to assess timing and voltage margins.
PCB and Substrate Design Updates
When design prototypes reveal issues like high-frequency attenuation, excessive dispersion, or eye closure, targeted revisions are essential. We review your design using advanced simulation tools and we then recommend updates that restore signal integrity before prototyping.
- Stackup Design - We often find that simple changes to the stackup or materials can have a big impact on signal integrity, especially at high frequencies.
- Material Validation - We evaluate the impact of stackup materials at progressively higher frequencies and identify interconnect changes that improve performance.
- Via Optimization - We use our tools and experience to determine appropriate via geometries to support high-bandwidth channels without excessive return loss.
- Signal Integrity Verification - Updates are confirmed with channel compliance simulations in the time and frequency domains.
We offer PCB design services for a range of products, spanning high-speed digital systems, power systems, aggressive form factors, and RF devices. Upon completing a design review, we provide a detailed report outlining the required changes and a quote for the design updates. We use industry-standard enterprise-level PCB design software for all client projects.
PCB Design Software Support
Related Resources
Do Differential Pairs Require a PCB Ground Plane?
By ZM Peterson • Dec 7, 2024Differential pairs require a measurement reference, which could be a PCB ground plane or the other trace in the pair.
PCB Design Software Options For Your High-Speed PCB Project
By A Mughees • Sep 10, 2024Learn how to choose the best PCB design software for your high-speed PCB design projects.
Our Signal Integrity Consulting Process
We provide customers with PCB design and advanced packaging design solutions to accelearte the innovation process for cutting-edge electronics.- Contact us for a consultation and quote.
- Send us all available design data for your PCB or IC substrate, including documentation detailing pinouts/ball-outs, interface standards or bandwidth requirements, and relevant component details in schematics. If any specialized models (e.g., IBIS or Touchstone) are needed, include these in your data package.
- We'll run simulations to evaluate the target design against system requirements and use our experience to propose ways to optimize your design.
- Throughout the design process, we'll collaborate with you on any required design changes and provide suggestions to improve your new product.
Why Work With NWES?
- Broad expertise - We're a digitally-driven remote-first organization with diverse talent and experience. We know your technology because we've used it and built it.
- Manufacturing partners - We work with local and overseas CMs and EMS providers that are ISO-9001, AS9100, ISO-13485, IPC-A-610, NADCAP, and/or ITAR/JCP certified. We help you find the best option to produce prototypes and scale to volume production.
- Supply chain management - We take a proactive approach on projects to ensure your design can be produced at the required volume. We'll manage procurement from major distributors or brokers throughout your project.
Need a hand with a current or future IC substrate design project? Find out the difference our experts can make.
Contact us today for more information.
Our Clients and Partners
