ESD Testing, Certification & ESD-Safe Design
Measured impact on ESD robustness
ESD robustness should be measured against system response, not voltage alone. Useful outputs include the required level passed, discharge points that cause communication errors or resets, recovery behavior, failure location, and verification after corrective changes. This provides evidence for reliability, risk control, and compliance testing.
How we design and verify ESD-safe hardware
Reliable protection depends on the enclosure, PCB layout, ESD protection circuits, grounding, interfaces, and firmware working as one system. Design decisions and pre-compliance testing are therefore part of the same engineering process.
Design for controlled ESD current
- We select TVS diodes and other ESD protection components based on electrical characteristics, interface requirements, clamping behavior, and the expected ESD pulse.
- PCB layout controls the ESD current path with short returns, suitable spacing, connector shielding, and attention to USB ports, enclosure seams, and human contact points.
- Firmware can monitor faults and recover cleanly when ESD events cause a temporary functional upset without permanent damage.
Pre-compliance and EPA control
- An ESD simulator applies controlled contact discharge, air discharge, and indirect discharge while engineers evaluate device function and performance degradation.
- Pre-compliance identifies weak points before accredited compliance testing and supports failure analysis when a product fails.
- In production, an ESD protected area combines grounding, conductive surface controls, packaging, personnel controls, training, electrical continuity checks, and verification to manage static electricity.
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What defines an ESD-robust product
An ESD-robust product connects real world conditions with controlled testing, clear acceptance criteria, and production controls. Product immunity and EPA compliance address different risks, but both contribute to reliable operation.
Testing targets accessible conductive and insulating surfaces, connectors, controls, and coupling paths that represent real world environments where human contact and different electrical potentials can create a static discharge.
Pre-compliance uses the applicable discharge modes, voltage levels, test methods, and monitoring to evaluate likely compliance before formal certification. Weak points can then be corrected while changes to the circuit design remain practical.
A robust design can still be damaged during assembly. EPA controls, grounded workstations, packaging, resistance checks, handling procedures, and compliance verification protect sensitive components before the finished device reaches customers.
In-house scope vs. accredited laboratory
ESD work often combines engineering tests during development with formal testing by an accredited laboratory. The split depends on industry standards, customer requirements, product type, and the evidence required for certification.
What InTechHouse does in-house
We can also support EPA planning by reviewing grounding, handling controls, training, protective materials, and verification methods against the selected ESD control standard.
What an accredited laboratory does
Facility certification to ANSI/ESD S20.20 is different. An accredited certification body audits the facility's ESD control program rather than testing finished-product immunity. The ESD Association's facility certification program is based on ANSI/ESD S20.20 or IEC 61340-5-1.
IEC 61000-4-2 ESD test levels and performance criteria
IEC 61000-4-2:2025 defines standard severity levels for system-level ESD immunity testing of electrical and electronic equipment (IEC, 2025). A test result depends on both the applied discharge voltage and the permitted system response during and after the ESD event.
Contact discharge: 2 kV
Air discharge: 2 kV
The lowest predefined IEC 61000-4-2 severity level (IEC, 2025).
Contact discharge: 4 kV
Air discharge: 4 kV
A higher predefined severity level for increased ESD immunity requirements (IEC, 2025).
Contact discharge: 6 kV
Air discharge: 8 kV
At this level, air discharge is tested at a higher voltage than contact discharge (IEC, 2025).
Contact discharge: 8 kV
Air discharge: 15 kV
The highest predefined IEC 61000-4-2 severity level (IEC, 2025).
Contact discharge: Special
Air discharge: Special
Test voltages are defined separately by the applicable specification or test program (IEC, 2025).
The equipment continues operating as intended during and after the ESD event, with performance remaining within the specified limits.
Temporary performance degradation is permitted during the ESD event, but the equipment must recover automatically without operator intervention.
Temporary loss of function or performance degradation is permitted if normal operation can be restored through operator intervention or a system restart.
Typical failure modes and the design fixes that prevent them
ESD failures become useful engineering evidence when the observed symptom is linked to the ESD current path, physical mechanism, and a specific design correction.
Symptom on test: A USB, serial, Ethernet, or other interface resets or reports communication errors.
Physical mechanism: ESD current couples into signal, reference, or reset circuitry.
Design fix: Improve TVS placement, return paths, connector shielding, filtering, grounding, and firmware recovery.
Symptom on test: The device or interface remains failed after the ESD event.
Physical mechanism: The pulse exceeds the protection capacity of the component or protection circuit.
Design fix: Select suitable ESD protection components, reduce parasitic inductance, and redirect current away from sensitive circuitry.
Symptom on test: Touch inputs, sensors, or control lines trigger unexpectedly.
Physical mechanism: Capacitive or conductive coupling injects a transient into a sensitive node.
Design fix: Adjust filtering, shielding, PCB layout, debounce logic, and return paths.
Use Cases
We design and develop embedded systems for UAV platforms, integrating sensors, communication modules, and control logic for real-time operation. Our solutions are engineered for mission-critical environments, ensuring reliable performance, low latency, and seamless system integration. Each design supports stable operation under dynamic conditions while maintaining data integrity and operational efficiency.
We design and develop firmware for industrial equipment, enabling reliable communication, data acquisition, and system control under real operating conditions. We focus on robustness, real-time performance, and seamless integration with hardware and higher-level systems. Each implementation provides stability, scalability, and long-term maintainability in demanding industrial environments. We als optimize for resource efficiency and compliance with industry protocols.
We design and develop firmware for subsea systems focusing on predictable real-time operation, fault tolerance, and robust communication in harsh underwater environments. Each implementation allows consistent performance under pressure, limited accessibility, and long-term deployment conditions. We also support integration with monitoring and diagnostic systems to enable remote operation and maintenance.
We design and implement advanced embedded software for imaging systems, including real-time processing, camera control, and data integration. Our solutions are optimized for high performance, low latency, and seamless interaction with hardware components. Each implementation ensures stable operation, high data throughput, and reliable system behavior. We also support integration with higher-level systems and data pipelines for end-to-end functionality.
Industries We Serve
Our engineering capabilities are deployed across regulated, mission-critical and industrial sectors.
Subsea electronics, downhole systems and harsh-environment hardware for offshore and onshore operations.
Mission-critical embedded systems and real-time firmware for UAV platforms and defence electronics.
Real-time embedded firmware for gas detection, environmental sensing and worker alert systems.
Embedded systems and real-time firmware for industrial automation,
machine control and IoT data acquisition.
Technologies we use
The exact equipment and chamber capacity depend on the DUT, exposure profile, required standard, and available test facility. Our expertise focuses on defining the right test conditions, monitoring device function, interpreting failures, and converting results into design changes.
FAQs
If you have additional questions or would like to discuss your requirements, feel free to get in touch with our team.
ESD certification can refer to finished-product immunity or facility ESD control. IEC 61000-4-2 covers product immunity, while ANSI/ESD S20.20 covers controls used to protect ESD-sensitive items during handling and manufacturing.
IEC 61000-4-2:2025 is the basic EMC standard for evaluating electronic equipment immunity to electrostatic discharge (IEC, 2025). It defines the ESD waveform, voltage levels, test setup, contact and air discharge methods, calibration, and evaluation procedures.
Contact discharge applies the ESD pulse directly to a conductive surface through the simulator tip. Air discharge approaches an insulating surface until an arc occurs, reproducing a discharge across an air gap.
TVS diodes provide a low-impedance path for transient ESD current and limit the voltage reaching downstream circuitry. Correct selection and PCB placement are critical because clamping voltage, capacitance, current path, and trace inductance affect system-level protection.
A TVS diode alone does not make a product ESD-robust. Enclosure design, grounding, connector shielding, PCB layout, return paths, filtering, and firmware recovery also affect how ESD energy moves through the system.
Yes. ESD can cause permanent failure, latent damage, or a temporary functional upset. Electronic components may also be vulnerable at voltages far below the level a person can perceive.
NASA training material states that people typically perceive electrostatic discharge at approximately 3,500 V or above, while discharges of 50 V or less can still damage sensitive devices (NASA, 2026). This is one reason component handling requires ESD controls even when no spark is visible or felt.
An ESD protected area, or EPA, is a controlled area where ESD-sensitive components and assemblies are handled using defined grounding and static-control measures. Controls can include personnel grounding, suitable work surfaces, packaging, handling procedures, and verification of protective equipment.
ESD-sensitive components need packaging selected for their susceptibility and the conditions of production, transport, and storage. ANSI/ESD S541-2026 defines properties and requirements for packaging used to protect ESD-sensitive items and supports ESD control programs based on ANSI/ESD S20.20 (ESD Association, 2026).
A practical classification is catastrophic failure, latent damage, and soft or temporary functional upset. Catastrophic damage stops the affected function immediately, latent damage can weaken a component without immediate failure, and a soft failure temporarily affects system operation.
The required level depends on the applicable product standard, industry requirement, customer specification, and intended environment. IEC 61000-4-2 defines the system-level test method and standard severity levels, but the appropriate level and performance criterion must be selected for the product.
Selecting components with suitable ESD capability also matters, but component withstand ratings cannot replace system-level testing because discharge current can couple through enclosures, interfaces, grounding, and PCB paths.
ANSI/ESD S20.20-2021 defines requirements for establishing, implementing, and maintaining an ESD control program for sensitive electronic parts and assemblies (ESD Association, 2021). The program includes technical controls as well as training and compliance verification.
Training and verification are ongoing activities rather than one-time certification tasks. Audits can identify grounding, handling, equipment, or process deficiencies that require corrective action.
The applicable standard depends on the equipment and program. RTCA DO-160G includes electrostatic discharge testing for airborne equipment in Section 25 (RTCA, 2010), while MIL-STD-461G CS118 addresses personnel-borne ESD for applicable military electrical, electronic, and electromechanical equipment (U.S. DoD, 2015).
CS118 applies to equipment with a human-machine interface and evaluates whether the equipment can withstand personnel-borne ESD without unacceptable malfunction or performance degradation.
Yes. Pre-compliance electrostatic discharge testing can identify susceptible interfaces, compare TVS and PCB changes, evaluate system response, and prepare a device for formal testing.
An ESD simulator can reproduce controlled discharge events at the required voltage levels, but internal testing does not replace accredited evidence when a contract, certification program, or applicable standard requires formal laboratory testing.
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