PCB Design Review Without an Altium License: SI, PI, EMC, and DFM in Every Flux Plan
You do not need an Altium or Cadence seat to get a professional PCB design review. Every Flux plan includes the Flux agent, and the agent runs signal integrity (SI), power integrity (PI), EMC, and design for manufacturing (DFM) review on your design. Ask in your project. Flux simulates the routed board, checks it against your rules and your fabricator, fixes the issues it finds, and reviews the mechanical parts of the device in the same pass.
Altium-level review. No Altium seat. No specialist on the calendar.
The review was always the expensive part
Drawing a schematic is not where traditional EDA makes its money. Review is. The checks that decide whether a board works the first time sit behind the most expensive licenses in the industry.
An Altium subscription costs thousands of dollars per seat every year. Our guide to the best PCB design software in 2026 puts it at $3,500 to $7,500 per seat per year. In the Cadence world, signal and power integrity analysis is its own product line, Sigrity, with its own licenses on top of the layout tool.
The license is only half of the cost. Someone has to know how to set up the analysis, read the plots, and turn them into layout changes. On most teams that is one SI specialist or an outside consultant. The board waits for their calendar. A review cycle takes days, and a second round after the fixes takes days more.
So teams ration review. The high-speed boards get it. Everything else ships on hope and a DRC pass.
In Flux, the reviewer comes with the plan
Flux is AI first. The agent works with the same routing, length tuning, simulation, and design check tools that you see in the editor, and it combines them into a review. You do not buy an analysis license. You do not learn a solver setup. You ask, the way you would ask a senior engineer on your team.
“Review this board for signal integrity, power integrity, EMC, and manufacturability before we order it. Fix what you can and list the rest.”
Flux reads the schematic, the routed copper, the stackup, the datasheets, and the manufacturing profile. It runs the analysis, changes the layout, runs the checks again, and gives you a report in the chat. In Flux, a full review takes hours, not the weeks it takes to schedule licenses and people.
Signal integrity review
Flux runs full-wave electromagnetic simulation on your routed board, with the real copper and the real stackup. Ask it to analyze a USB, PCIe, Ethernet, or DDR interface. It reports differential S-parameters (SDD11 and SDD21), differential impedance (Zdiff), TDR response, crosstalk, and an eye diagram at the bit rate you name.
“Analyze the PCIe lanes. Plot the eye at 8 Gbps, report Zdiff and crosstalk to the neighboring nets, and fix any pair that misses 85 ohms.”
Then the agent acts on the result. It adjusts trace widths and spacing for the impedance target, re-tunes lengths and skew with trombone, accordion, or sawtooth patterns, and length-matches DDR, QSPI, and SDIO lanes. It runs the simulation again to confirm the change. See electromagnetic simulation of your routed board for three real examples.
Power integrity review
Flux analyzes the power delivery network (PDN) of the routed board. It plots PDN impedance across frequency with the vendor models of your capacitors, including ESR and ESL. It calculates IR drop on planes and traces, finds plane resonances, and simulates the voltage droop of a load step on a rail.
“Check the 1.2 V core rail against a 50 milliohm target from 10 kHz to 100 MHz. Pick the decoupling capacitors and simulate a 0.5 A to 2 A load step.”
Flux selects decoupling capacitors for the target impedance and places them. It checks the placement and routing of each switching power stage: the regulator, the inductor, the input and output capacitors, and the switch path. It sizes power traces for their current and estimates board temperatures from the operating conditions. Read PDN design for PCBs for the background.
EMC review
EMC problems start in layout: broken return paths, long switching loops, unmatched pairs, and noisy nets next to sensitive ones. Flux reviews the board for all of them, because it can see and simulate all of them.
“Do an EMC review of this layout. Check the return paths under the high-speed nets, the switching loop of the buck converter, and the coupling from the motor driver into the sensor lines.”
The agent checks the reference planes and ground fills under critical nets. It simulates crosstalk between aggressor and victim nets. It tightens differential pair coupling and skew, so the common-mode signal stays low. It shortens switching loops, keeps antenna areas clear, and checks that connectors sit at the board edge where cables leave the enclosure. Then it fixes the layout and runs the check again. See the EMI and EMC PCB design guide for the design rules it applies.
DFM review for the board and the mechanical parts
Flux runs the design rule check and the electrical rule check, then fixes clearance errors, floating copper, unrouted nets, missing decoupling, and missing pull-ups. It compares the board with the rules of your manufacturing profile. It sets up blind, buried, and microvias for HDI stackups and fans out dense BGAs.
Before you order, Flux can check the exported manufacturing files themselves. It compares Gerber copper gaps with the fabricator's minimum spacing, checks the silkscreen and the board outline, renders each layer, runs a design rule check on the exported board, and cross-checks the BOM and pick-and-place files against the design.
A device is more than its board. Flux reviews the mechanical parts with the same agent. It checks an enclosure for SLA or SLS printing, a bracket for CNC milling, a cover for sheet metal or injection molding, and applies the limits of each process. It checks the fit and clearance between the board, its connectors, and the enclosure cutouts. It analyzes stress and deflection of mounting brackets and simulates the air flow and temperature inside the enclosure.
“Check the enclosure for injection molding and the bracket for CNC in 6061 aluminum. Confirm the USB-C connector lines up with the cutout and that the board stays under 70 °C with the vents as drawn.”
See PCB design for manufacturability for the board checklist.
Do the seat math
A team of five engineers on a traditional EDA suite pays for five layout seats, then for the analysis licenses, then for the specialist who knows how to run them. Most of the boards still never get a full review.
In Flux, every engineer on every plan has a reviewer who runs SI, PI, EMC, and DFM checks on request, fixes the issues, and covers the mechanical design too. Review stops being a gate that you budget for. It becomes a step you run on every revision, in hours.
Compare the details in Flux vs Altium and Flux vs Cadence, see Flux pricing, or open a project in Flux and ask for your first review.
FAQ
Yes. Flux runs full-wave electromagnetic simulation on your routed board and reports S-parameters, differential impedance, TDR, crosstalk, and eye diagrams. Ask the Flux agent in your project. No separate analysis license is needed.
Every Flux plan includes the Flux agent and monthly AI usage. The agent runs signal integrity, power integrity, EMC, and DFM review, the design rule check and electrical rule check, manufacturing-file checks, and mechanical checks such as fit, stress, thermal, and process limits.
Yes. Flux changes the layout to fix the issues, for example trace widths for impedance, length and skew tuning, decoupling capacitors, and clearance errors. Then it runs the analysis or check again and reports the result.
Flux plots PDN impedance with vendor capacitor models that include ESR and ESL, calculates IR drop, finds plane resonances, and simulates load-step droop. It selects decoupling capacitors for your target impedance and checks the layout of switching power stages.
Yes. Flux checks enclosures, brackets, and covers against the limits of SLA, SLS/MJF, CNC milling, sheet metal, laser cutting, and injection molding. It also checks fit and clearance between the board and the enclosure, and analyzes stress, deflection, and air flow.
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