High-speed signals do not tolerate impedance discontinuities. When your flex circuit carries LVDS, USB 3.x, PCIe, MIPI, automotive Ethernet, or RF signals above 100 MHz, controlled impedance is not optional — it is a fundamental design requirement. FlexiPCB manufactures impedance-controlled flex circuits from 1 to 10 layers, using calibrated polyimide substrates with known dielectric constant (Dk 3.2-3.5 at 1 GHz) and tightly controlled copper trace geometry. We model every impedance stackup with 2D electromagnetic field solvers before production begins, then verify every panel with time-domain reflectometry (TDR) testing to confirm your target impedance within ±5% tolerance. Whether you need a single-ended 50-ohm microstrip for an RF antenna feed, a 100-ohm differential pair for USB 3.2, or a coplanar waveguide for 5G mmWave, our process controls — dielectric thickness ±10%, etch factor compensation, and coverlay registration — ensure consistent impedance from first article through volume production.
USB 3.x, PCIe Gen 4/5, HDMI 2.1, and DisplayPort require controlled-impedance differential pairs with tight coupling and length matching. Our flex circuits maintain 90/100-ohm differential impedance across dynamic bend zones without discontinuities — critical when routing high-speed buses through hinges, sliders, and folding mechanisms.
100BASE-T1 and 1000BASE-T1 automotive Ethernet over flex circuits demand 100-ohm differential impedance with strict return loss requirements. FlexiPCB manufactures impedance-controlled flex harnesses for camera modules, radar interconnects, and LiDAR sensor chains that meet AEC-Q100 reliability and IATF 16949 process standards.
Antenna feeds, filter interconnects, and RF front-end modules require 50-ohm controlled impedance with minimal insertion loss. Our coplanar waveguide and microstrip designs on low-loss polyimide deliver consistent impedance from sub-GHz ISM bands through 5G mmWave frequencies at 28 GHz and beyond.
Ultrasound transducer arrays and CT scanner interconnects require impedance-controlled flex circuits with dozens to hundreds of matched channels. We manufacture multi-layer flex with controlled impedance on every signal layer, biocompatible materials, and cleanliness levels suitable for Class II and Class III medical devices.
MIPI CSI-2 and DSI interfaces in smartphones, tablets, and automotive cameras use impedance-controlled flex cables with 100-ohm differential pairs. Our ultra-thin constructions (total thickness under 0.15mm) maintain impedance accuracy through 180-degree fold zones with bend radii as small as 1.5mm.
Oscilloscope probes, signal analyzers, and ATE (automated test equipment) require broadband 50-ohm impedance-controlled flex interconnects. Our TDR-verified flex circuits deliver ±3% impedance tolerance with characterized insertion loss from DC to 40 GHz for precision measurement applications.
Our signal integrity engineers import your impedance requirements and model the optimal stackup using 2D electromagnetic field solvers. We calculate trace width, spacing, and dielectric thickness for each impedance target, accounting for polyimide Dk variation across frequency, etch compensation factors, and coverlay dielectric effects.
We select polyimide laminates with characterized dielectric properties (Dk, Df) at your operating frequency. Every incoming lot is verified for dielectric thickness, copper foil thickness, and surface roughness — all parameters that directly affect impedance. Adhesiveless laminates are specified when dielectric tolerance is critical.
Trace geometry is the primary impedance variable. We use LDI (laser direct imaging) for ±10 µm registration accuracy and tightly controlled etch processes to maintain trace width within ±10% of target. Etch factor compensation is pre-calculated in the CAM data to account for copper undercut during wet etching.
Multi-layer impedance flex requires precise dielectric thickness between signal and reference planes. Our vacuum lamination process controls prepreg flow and final dielectric thickness within ±10% of nominal — the single most critical parameter for impedance accuracy.
Every production panel includes impedance test coupons that replicate your actual trace geometries. We measure these coupons with calibrated TDR equipment per IPC-TM-650 2.5.5.7, generating impedance traces that verify compliance with your target ±5% (or ±3%) tolerance. TDR data is included in your quality documentation package.
Completed flex circuits undergo full electrical testing (open/short, isolation), dimensional inspection, and visual inspection per IPC-A-610. The impedance test report — including TDR waveforms, measured values, and statistical analysis — ships with every order as part of our standard quality documentation.
We do not guess trace widths from lookup tables. Every impedance stackup is modeled with 2D field solvers using your actual material properties, layer construction, and soldermask/coverlay — and we share the modeling report before production begins.
Impedance compliance is not sampled — it is verified on every production panel via TDR test coupons that replicate your actual trace geometry. Calibrated equipment, traceable standards, and full test reports included with delivery.
Our dielectric thickness control (±10%), trace width control (±10%), and process repeatability deliver ±5% impedance tolerance as standard. For precision RF and measurement applications, we achieve ±3% with material selection and tighter process windows.
From automotive Ethernet at 100 MHz to 5G mmWave at 28 GHz to test equipment at 40 GHz — we have manufactured impedance-controlled flex circuits across the frequency spectrum. Our material database includes characterized Dk/Df data at your operating frequency.
