What is the Scope of a Professional PCB Design Review?

A well conducted review will look at more than just the visuals, it will relate the schematic and layout to the mechanical design and behavior of firmware, and manufacturing.

The aspects that can be reviewed include:

  • Schematic correctness and parts parameters
  • Placement and layout of PCB
  • Connections with controlled impedance
  • Signal and power integrity
  • Integration and tuning of RF antennas
  • EMI emissions and immunity problems
  • Thermal behavior
  • PCB stack-up and reference planes
  • Component lifecycle and availability
  • DFM and DFT
  • Accessibility of test points
  • Programming and provisioning
  • Potential production yield problems
  • The documentation of design and right to it

The findings are grouped according to their severity and followed by practical advice. If some conclusions cannot be drawn from the documents, we specify the measurement that will prove or disprove our hypothesis.

Controlled-Impedance and Signal Integrity Review

Just like the way in which electrical signals travel through wires is influenced by the electrical characteristics of the circuit, high-speed signals behavior doesn't solely depend on wires either. Traces, pins, connectors, and reference planes create the electrical channel.

This review covers interface-specific requirements for USB, Ethernet, MIPI, DDR, LVDS, CAN, and some other digital connections.

Our work validates so-called impedance targets, geometry of differential pairs, length limitations, reference plane continuity, via transition process, distances between the signals, termination process, and connector placement.

Length matching is not the only principle taken into account; while using pairs correctly matched in length, it is necessary to avoid different plane splitting, significant via stubs, and incorrect stack-up.

In situations when modeling can be performed and it is possible to acquire the needed models, signal integrity analysis can be conducted.

The document must include the assumptions made in the process of creating a model and all components employed for the analysis.

Power Integrity and Thermal Review

Many apparent signal failures begin with the power-delivery network.

We review regulator selection, power sequencing, current paths, decoupling, bulk capacitance, plane connections and switching-loop geometry. Particular attention is given to processors, radios, motors, cameras and LED drivers that create changing current demand.

Thermal analysis considers component losses, copper spreading, thermal vias, airflow and enclosure contact. A device tested on an open bench may run considerably hotter once installed in a sealed housing.

Power and thermal findings are therefore evaluated under realistic operating modes, including wireless transmission, charging, processing peaks and fault conditions.

RF Antenna Placement and Matching Review

Wireless performance involves more than just choosing a certified module or copying a reference antenna.

The review covers the antenna location, keep-out zones, the layout of the ground plane, routing of the feed, matching circuits, nearby batteries, connectors, interconnecting cables, and enclosure materials.

We also address whether the final product could be tested and adjusted. For custom RF paths, controlled routing, and matching should be designed according to the actual PCB stack-up. Antenna performance should be verified in the final enclosure because plastic, metal, people, and position could alter its properties.

Case Study: EMC and Signal Integrity Remediation for a Medical Wearable

EMC medical wearable engineering case study featuring PCB design, electromagnetic compatibility testing, EMI reduction, and IEC 60601 compliance for wearable medical devices.
Phase 01 · Client Situation

Client Situation and Initial Review

Adequate Infosoft was asked to review an existing BLE-enabled medical wearable developed by a confidential healthcare-device company.

The medical device contained an STM32L496 chip, Nordic nRF52840 chip, DRV8876 stimulator, rechargeable 500mAh battery and auxiliary power management circuits. Although the circuit board was already designed, it had to comply with IEC 60601 certification requirements for safety and EMC.

The assessment showed that patient-connected circuits, wireless systems, and USB power connections were not isolated properly. There were problems with emitted radiation levels from the circuit board as well as issues with Bluetooth communication during stimulation.

Phase 02 · Root Cause

EMI Measurements and Root-Cause Analysis

The first open-board pre-compliance scan identified three important emissions:

  • 52.1 dBµV/m at 480 MHz against a 46 dBµV/m limit
  • 49.3 dBµV/m at 2.45 GHz against a 47 dBµV/m limit
  • 44.2 dBµV/m at 122 MHz against a 43 dBµV/m limit

The 480 MHz emission was traced to harmonics associated with the TPS63900 switching converter and insufficient input filtering.

At 2.45 GHz, the review identified antenna-network and ground-stitching concerns around the nRF52840 radio. The 122 MHz problem involved clock-related energy escaping through the unshielded programming connection.

A separate coexistence problem occurred during stimulation. The H-bridge switching activity introduced ground disturbance into the shared digital domain. BLE packet-error rate increased from approximately 0.1% to 15%, producing connection drops.

Phase 03 · Remediation

PCB and Circuit Remediation

The redesign featured an introduction of a ferrite bead and capacitors at power inlet, a new arrangement of nRF52840 matching network, and also the addition of some filtering close to SWD programming header.

High-frequency wiring was placed at more appropriately referenced internal zones of the six-layer stack-up design. The ground was split into logic and patient side domains and an external 32 kHz crystal was introduced to strengthen radio timing precision.

The safety redesign added digital isolation and an isolated DC-DC supply. A routed PCB slot and revised copper clearance increased the relevant creepage distance from 2.1 mm to 10.2 mm.

Battery safety was also addressed by reducing charge current, adding temperature monitoring and incorporating independent over-temperature protection.

Phase 04 · Outcome

Verified Outcome and Production Preparation

During the second enclosed pre-compliance scan, the measured emissions fell to:

  • 38.2 dBµV/m at 480 MHz, providing a 7.8 dB passing margin
  • 42.1 dBµV/m at 2.45 GHz, providing a 4.9 dB margin
  • 39.5 dBµV/m at 122 MHz, providing a 3.5 dB margin

In the worst-case scenario, the BLE packet error rate was lowered to 0.2%, and the published case study shows no disconnects during the 72-hour soak test.

The engagement also included the generation of specifications for dielectric strength, leakage current and continuity measurements, as well as guidance on the fixture for the contract manufacturer.

The project is a clear indication of what a proper PCB review should be able to achieve; find possible failure modes, change the circuit design and validate the results by means of repeatable testing.

Case Study URL: iec-60601-wearable-remediation-nrf52840-stm32

Relevant Case Studies That Demonstrate Our Review Experience

The following published projects demonstrate practical experience with signal integrity, EMC, grounding, thermal analysis and board validation.

AI-Powered Industrial Camera
Industrial Camera

AI-Powered Industrial Camera

For a North American industrial automation startup, Adequate Infosoft developed a compact eight-layer AI camera board integrating MIPI CSI-2, DDR3, Ethernet, industrial I/O and an Edge TPU.

The first PCB revision exposed a MIPI signal-integrity problem. Routing was revised using controlled differential impedance, tighter length matching and improved shielding. Thermal throttling was addressed through an enclosure-coupled heat path.

The finished system passed the documented industrial EMC and vibration evaluations and was deployed across three manufacturing facilities.

Read the AI camera case study
NXP S32K Vehicle Telematics Tracker
Automotive

NXP S32K Vehicle Telematics Tracker

In our vehicle telematics project, a six-layer printed circuit board was employed, in which the components involved an NXP S32K344, CAN FD, LTE, GPS, and automotive-level protection circuit.

The controlled-impedance routes with ground referring and isolation techniques were applied to routes of LTE and GPS antennas. ANSYS SIwave software has been mentioned, which has been utilized in high-speed signal integrity verification according to the published project.

This project confirms the experience in review related to RF and communication busses, as well as automotive transients and environmental requirements.

Read the telematics case study
TI MSP430 Capacitive Touch Panel
Touch Panel

TI MSP430 Capacitive Touch Panel

A home appliance producer wanted to develop a control panel with reliable capacitive sensing that was waterproof.

The evaluation and prototype tests highlighted problems occurring with LED switching interference along with programming and USB-to-serial operations.

The design was changed and interference along with conflicts resolved with the help of isolation jumpers.

Read the touch panel case study
Silicon Labs Industrial Wireless Sensor
Industrial IoT

Silicon Labs Industrial Wireless Sensor

As far as MVIKAS Technologies P Ltd is concerned, Adequate Infosoft carried out the implementation of an industrial monitoring system based on the use of EFR32 to control vibration, temperature, humidity and power parameters.

The implementation of this solution proved the use of multilayer PCB, wireless communication systems based on mesh topology, low-power firmware, industrial casing and manufacturing quality assurance process.

Read the industrial sensor case study

Manufacturing Review: Where Good Layouts Become Good Products

The thought process of professional PCB customers includes the assessment of production and testing capabilities that PCB manufacturers possess rather than just determining the ability of one prototype to perform.

Availability of Components

We analyze the lifecycle status of components involved as well as the lead times, authority of suppliers, and dependence on alternatives. Potential features of alternatives are identified to confirm that electrical, mechanical, thermal, and firmware compatibility is ensured.

DFM and DFT

The Design for Manufacturing process considers manufacturing and assembly limitations like sizes of holes, clearances for solder mask, placement of components, panelisation, and access for inspection.

While the Design for Test process highlights power measurements, programming, calibration faults, and functional verification.

Test-Point Accessibility

Test points must be placed by the fixture that will reach them without interrupting any signals critical to the functioning of the device. Great caution has to be exercised in case of high-speed interfaces since adding unnecessary pads and stubs may have a negative effect on the channel.

Factory Programming

We review access to SWD, JTAG, UART or other programming interfaces, along with boot configuration, firmware verification, unique device identities and credential provisioning.

Production Yield

Pilot-build results should record solder defects, programming failures, rework and functional-test outcomes. Yield decisions should be based on production data rather than a single successful engineering sample.

Complete Title of Design Files

The ownership and transfer of design files should be defined before the start of the project. Deliverables can consist of editable schematics, original PCB documents, libraries, stacking information, production outputs and BOM basis, manuals for assembly, testing and updates.

Tools of other companies, licenses for use of libraries and manufacturer's information should also be clearly indicated.

Deliverables Offered in the PCB Assessment

The contents of a review package depend on the nature of the project:

  • Inspected schematic and PCB layout documents
  • Risk severity rankings
  • Recommendations regarding stack-up and impedance
  • Methods to improve electromagnetic interference and compatibility
  • Advice on signal and power integrity
  • Comments on RF and antennas
  • Tips on heat removal and component placement
  • Recommendations regarding design for manufacturing and design for testing
  • Recommended tests and measurement conditions
  • Implementation assistance and recommendations regarding priority of modifications

Request an Independent PCB Review

Before proceeding with the building, certification and production, you should let Adequate Infosoft identify design risks that cannot be detected by means of automated rule checks.

Send us your schematic, PCB files, stack-up, BOM, enclosure data and any test results available. We are able to provide a review of your product which covers all aspects of electrical performance, as well as compliance-related issues, manufacturability, testing, and ownership issues.

Frequently Asked Questions

Should a review happen before or after PCB routing?

Both processes have their importance. The review of schematics and architecture identifies critical problems long before the routing takes place. The review after the layout phase assesses the quality of the file in terms of routing, return paths, thermal properties, and its readiness for fabrication.

Can you guarantee that a board will pass EMC certification?

No responsible engineering company should guarantee a test result without evidence. We reduce risk through design review, simulation where appropriate, prototype measurement and pre-compliance testing.

Can you review files created by another engineering team?

Absolutely! The independent review can be carried out without having to replace the initial designer. Recommendations can be provided upon completion of the review or implemented as part of the controlled changes.

Editorial Sources

Adequate Infosoft

IEC 60601 Medical Wearable Remediation

Read source
Adequate Infosoft

IoT Wearable PCB Design and Prototyping

Read source
Texas Instruments

High-Speed Layout Guidelines

Read source
IPC

Electronics Standards and Qualification Resources

Read source
Omkar Prayag
Omkar Prayag
IPC CID+ Certified Hardware Designer
High-Speed PCB Layout Design | Signal Integrity (SI) & Power Integrity (PI) Analysis | Fault-Tolerant System Design | Multi-Layer PCB Development | Hardware Architecture & Circuit Design | Prototype to Production Engineering
LinkedIn IPC CID+ Certification IPC CID Certificate