As vehicle engineering and digital systems converge, the vehicle itself is being reimagined and software-defined at its foundation – not with software layered on afterward. At the center of this shift is connectivity, enabling secure updates, diagnostics, telemetry and more personalized experiences while providing the visibility and control needed to validate, maintain and continuously improve quality- and safety-critical functions.

Supporting communication across cellular, wi-fi, Bluetooth (BT), Bluetooth Low Energy (BLE), ultra-wideband (UWB) and high-precision Global Navigation Satellite System (GNSS) – alongside the compute and sensor-fusion demands of advanced driver assistance and autonomy – requires a robust, high-bandwidth architecture. For years, the industry met that need with a familiar compromise: more exterior antennas and long runs of heavy, costly coaxial cable routed to a centralized telematics control unit (TCU) buried deep within the cabin.

Today, the demands of massive data ingestion, split-second autonomous decision-making and over-the-air capabilities have pushed legacy architecture to its physical and economic limits.

GM’s modernized approach to vehicle connectivity

To support GM’s next-generation software-defined vehicle architecture – where connectivity must seamlessly deliver OTA updates, high-bandwidth infotainment and data-rich services – GM is converging on a radically different approach: the integrated Connectivity Hub Module (CHM). As a unified connectivity node, the CHM places all major radios at the optimal radio-frequency location and presents a clean, high-bandwidth digital interface into the electrical architecture’s core compute and broader vehicle network.

By integrating antennas directly with the connectivity electronics and placing the module at the optimal RF location – such as the roof – GM is rethinking the hardware foundation of the software-defined vehicle. This architectural choice dramatically improves cost, mass, volume and RF performance, but it also introduces complex multiphysics engineering challenges, most notably receiver desensitization, RF coexistence and thermal load.

How integrated CHM solves the traditional connectivity dilemma

In a classical connectivity stack, the system is explicitly divided: a roof-mounted ‘shark fin’ houses the passive or active antennas, while a TCU sits elsewhere in the vehicle, connected by up to 5m of dedicated coaxial cables.

While a modular approach places antennas in an ideal location, it brings severe physical and logistical bottlenecks. High-frequency signals, especially the gigahertz bands used in 5G cellular and wi-fi, experience significant insertion loss as they travel through long cables and impedance mismatches at connectors. This results in degraded performance and a significant part number count to manage at an enterprise level. Additionally, thick bundles of coaxial cables consume valuable packaging volume, add mass, complicate electromagnetic compatibility and require expensive connectors that complicate assembly-plant operations.

The integrated CHM collapses this distributed architecture into a single, highly optimized edge node. By combining the network processors, memory, RF transceivers, antenna arrays and a dedicated backup battery for OnStar functionality into a unified module, it acts as a complete, self-contained connectivity hub.

This consolidation provides immense engineering benefits, but realizing these advantages requires navigating the uncompromising laws of electromagnetics and thermodynamics.

Technical merits of antenna-TCU integration

GM has found that antenna integration provides an efficient approach to connectivity, with advantages that stretch across performance, design and overall system cost:

Eliminates cable loss and boosting performance
In RF engineering, every decibel of signal matters. A standard automotive coaxial run (transmission line) can degrade high-frequency signals by several decibels before even reaching the receiver. Integrating the antennas directly onto the CHM’s printed circuit board (PCB) and inside the same housing eliminates the cable run. This maximizes signal-to-noise ratio (SNR) and drastically improves the link budget, resulting in faster data throughput, greater range for high-bandwidth applications, and highly reliable connection even in fringe coverage areas where our customers adventure.

Addresses the desense challenge
While integration minimizes transmission line loss, it introduces one of the most notoriously difficult challenges in mixed-signal engineering: desense (receiver desensitization).

An integrated CHM is essentially a high-performance computer packed with ultra-fast gigabit ethernet switches, double-data-rate (DDR) memory interfaces, Peripheral Component Interconnect Express (PCIe) buses and high-current power supplies all radiating broadband electromagnetic noise. When highly sensitive receiver antennas are integrated right next to this roaring digital engine, the noise floor is artificially raised, effectively ‘blinding’ or desensitizing the antennas to faint incoming signals from cell towers or satellites.

Board-level desense control is a critical enabler for the CHM and demands aggressive EMC strategies. Engineers use intricate multicavity RF shields to isolate the digital system-on-chip from the RF front end, along with advanced PCB stack-ups featuring dedicated ground planes and buried stripline routing to contain return currents. They also tune drive strength and spread-spectrum clocks, and design localized filtering topologies that suppress harmonic noise at the source. Success depends on extreme physical packaging and lock-step coordination across electrical, software, mechanical and RF engineering.

Resolves the radio coexistence (coex) puzzle
If desense is the threat of internal digital noise, coexistence (coex) is the challenge of the radios shouting over one another. The CHM packs cellular, wi-fi, BT, BLE, UWB and GNSS into a highly constrained volume. These distinct radios frequently operate in adjacent or overlapping frequency bands. A high-power wi-fi transmission, for example, can easily spill into adjacent cellular bands or completely deafen the highly sensitive GNSS receiver.

Solving the coex puzzle requires a rigorous, multilayered approach. At the physical level, RF engineers must achieve every decibel of antenna isolation within a tiny footprint, leveraging spatial diversity and orthogonal polarization. Electrically, the board architecture relies on high-performance acoustic-wave filters to create incredibly sharp cutoffs between active bands. Finally, at the software layer, the CHM utilizes advanced time-domain multiplexing to intelligently coordinate transmission schedules, ensuring the radios interleave their signals without stepping on each other.

Powers the thermal management equation
Bringing the computing power of a TCU to the roof of the vehicle introduces a profound thermal challenge. The vehicle’s roof is subject to immense solar loading, often reaching extreme temperatures in the summer sun. Simultaneously, the 5G transceivers and network processors inside the CHM generate substantial internal heat.

Because the CHM must be heavily sealed against water and dust ingress, engineers cannot rely on active fan cooling. Instead, thermal management must be achieved through innovative mechanical design.

This approach uses the module’s cast-aluminum housing as a structural heat sink, and advanced thermal interface materials to move heat away from critical components. It also relies on intelligent software to dynamically throttle compute or transmission power during peak thermal events while preserving safety-critical communications.

Beyond RF and digital components, housing a battery in a roof-mounted module exacerbates the thermal and packaging challenges, requiring sophisticated charge-management algorithms to ensure reliability and safety across extreme temperature cycles.

Supports drastic reductions in mass and volume – and improved reliability
Automotive-grade RF cables are stiff, heavy and difficult to route during manufacturing. In addition to mass and volume, every interconnect is a potential failure point of the system and has historically led to quality challenges. By entirely stripping meters of multicore coaxial cabling out of the vehicle architecture, the CHM immediately yields mass reductions and reliability improvements. With electric vehicles, every gram saved contributes directly to range optimization and overall vehicle efficiency. This integration frees up critical volumetric space within the vehicle’s pillars, headliner and instrument panel, reducing the complexity of the overarching wiring harness designs and allowing greater freedom.

Optimizes system cost and manufacturing
Coaxial cables and their associated automotive-grade connectors are some of the most expensive passive components in a vehicle’s electrical architecture. They require rigorous validation to ensure they do not degrade over years of thermal cycling and vibration. Consolidating the antennas and electronics slashes the bill of materials. Additionally, installing a single CHM on the assembly line via a standard digital connection (such as automotive ethernet) is vastly more efficient than routing long RF cables and mating multiple fragile connectors, driving down labor costs and reducing potential manufacturing defects.

Conclusion

The integrated CHM is a necessary step for the future of intelligent vehicles. It trades the straightforward but inefficient legacy cable architectures for a highly optimized, physically demanding integrated design.

By balancing the aggressive performance demands of modern networks with the exacting physics of desense mitigation, thermal management and power resilience, the integrated CHM delivers a connectivity foundation that is lighter, more cost-effective and vastly more capable. This kind of foundational engineering within GM is shaping next-generation connected vehicles and redefining what it means to keep millions of people safe, informed and connected on the move.

In related news, Hyundai/GM alliance powers forward with five all-new vehicles

“Our customers expect a straightforward path from simulation model to microcontroller, and the new integration with Matlab and Simulink delivers exactly that,” said Brad Rex, senior director of the system solution team, user experience group at Renesas. “By working with MathWorks, we’ve removed the need to assemble toolchains and device drivers by hand so teams can simulate and validate designs earlier, iterate faster and reduce integration effort across ECU and industrial‑control projects.”

The Renesas RH850/U2A microcontroller – widely used in automotive ECUs – provides the deterministic performance and safety-critical features required for EV motor control, ADAS and body electronics. Engineers developing traction motor control for electric vehicles can deploy field‑oriented control and regenerative braking algorithms directly from Simulink to RH850/U2A‑based ECUs. This shortens the time from concept to vehicle‑level testing, supports smoother torque delivery during rapid transients and speeds calibration across drive cycles – without writing initialization code or custom build scripts.

Said Anuja Apte, India product marketing manager at MathWorks, “Our collaboration with Renesas strengthens the level of interoperability that engineers expect when using Matlab and Simulink. By providing a direct path from Simulink models to optimized microcontroller deployment, we help engineering teams move from design to hardware more efficiently while staying integrated with the broader toolchains they rely on. This approach reflects the MathWorks Connections program, which brings partners and customers together to accelerate innovation and reduce time-to-market within a widely adopted engineering and scientific platform.”

In related news, OmniTrust and Synopsys collaboration enables earlier security validation of embedded systems

In summary, rising demand could contribute to higher development costs for next-generation vehicle systems, such as autonomous driving, if the industry does not converge on interoperable standards.

According to TechInsights’ Automotive Ethernet – Architecture Change Drives Growth report, adoption of automotive ethernet is expanding rapidly but remains uneven across original equipment manufacturers (OEMs) and regions.

In response to the report, the OPEN Alliance has called for greater alignment around its specifications and best practices to reduce variability, limit duplicated integration effort and support more scalable deployments.

“Automotive ethernet is set for rapid yet uneven growth as new architectures, higher sensor bandwidth and emerging applications drive a near-tripling of ethernet sockets in vehicles by 2032,” said OPEN Alliance president Suma Prabhakara. “As regions like China grow in overall socket share but remain internally fragmented, the OPEN Alliance’s role in reducing variability and accelerating consistent, standards‑based adoption becomes even more important. We encourage OEMs and suppliers to align with our work and share their implementation experience.”

The report found that the automotive ethernet socket market is set to grow from approximately 962,000 sockets in 2025 to 3.42 million in 2032, with the average number of ethernet sockets per vehicle forecast to rise from 11 to 27 by 2030. However, the findings also note that a small group of advanced OEMs install 4.5 times more ethernet ports per vehicle than the rest of the market. This means that while adoption is growing across the market, the overall maturity levels are volatile and vary widely across different OEMs and regions.

“With so many new automotive ethernet technologies entering the market, the industry cannot afford fragmented approaches,” said OPEN Alliance board member Samuel Sigfridsson. “Standards-based implementation of automotive ethernet that has been tested according to OPEN Alliance’s test suites will ensure interoperability and prevent the costly divergence that slows innovation.”

The report combines a bottom-up socket forecast with qualitive validation from an industry survey spanning key semiconductor vendors, OEMs, Tier 1 suppliers, connector and harness suppliers and software companies.

According to the report, geopolitics is the top risk in terms of market destabilization. Researchers also found that the interplay of different technologies is set to shape the market’s trajectory – SERDES is expected to grow alongside, not be displaced by, ethernet, while time-sensitive networking (TSN) is projected to underpin nearly 50% of all ethernet-equipped vehicles by 2030. The report findings also highlight a major shift in automotive ethernet speed‑grade adoption, suggesting that automotive ethernet is prioritizing more high‑speed links, though adoption patterns remain uneven across OEMs and regions.

The report also provides an overview of application-level demands and potential plans for dispersion within the automotive market, along with a risk assessment overview.

The full report is available here

In related news, Kodiak AI announces autonomous trucking pilot in Canada

Guided by a shared vision of fully automated, CI/CD-connected development environments based on open standards and modern software practices, the suppliers aim to make HIL testing truly ‘soft’ – meaning software-driven –  as well as being flexible, scalable and seamlessly deployable. This is central to supporting the evolution toward software-defined vehicle architectures.

Gianluca Vitale, software global unit manager at AVL, said, “At AVL, our software strategy continues to evolve with a clear focus on accelerating development through end-to-end solution responsibility, positioning ourselves as an open integrator that enables customers to move faster and more efficiently.”

“Together with VCarSystem, we are introducing disruptive, end-to-end approaches that radically speed up software release cycles and E/E integration, offering a new benchmark for testing efficiency and development agility,” said Qi Chen, president of VCarSystem. “Partnering with AVL marks a significant step toward reshaping the future of vehicle development in the era of software-defined vehicles.

“As the industry shifts from hardware-bound architectures to software-driven mobility platforms, validation must evolve at the speed of software. Together with AVL, we are building an open, scalable testing ecosystem that accelerates function validation, shortens development cycles and enables continuous innovation throughout the SDV lifecycle – creating long-term sustainable value for our global customers and partners.”

Related news, MissionH24 accelerates hydrogen innovation with AVL Racetech simulation technology

By making this work available as an early preview, Codethink is inviting organizations interested in applying open source approaches to functional safety to review and begin working with the mapping while the work continues to mature. 

“This preview release reflects our belief that trust in software must be engineered in the open. We want organizations working at the cutting edge of safety-critical software to be able to review, evaluate and begin applying these mappings as they evolve,” said Paul Sherwood, chairman of Codethink. 

The Eclipse Trustable Software Framework defines six tenets – provenance, construction, changes, expectations, results and confidence – each aligned to the objectives of IEC 61508. This structure enables organizations to connect everyday software development practices with the rigor expected in safety-critical systems. 

Codethink plans to contribute the mapping to the Eclipse Trustable Software project once the company has achieved a successful functional safety assessment of CTRL OS using the TSF. This future contribution will build on the baseline assessment achieved last year and represents the next step in validating the framework in a production software environment. 

Until that milestone is reached, the mapping is being made available as an early preview for those interested in exploring open, transparent approaches to safety and compliance. 

“Our goal is simple, by demonstrating compliance with the Trustable Software Framework, organizations should be able to demonstrate alignment with the world’s most important safety and regulatory standards. Open collaboration is the fastest way to get there,” said Sherwood.  

The June edition of ATTI – read online here – will include a software feature investigating the latest in integrated testing, continuous integration and continuous development (CI/CD) and predictive testing

Related news, Codethink’s Eclipse Trustable Software Framework achieves positive functional safety assessment

Electromagnetic compatibility issues rarely stem from a single component or test failure. More often, they originate from design decisions made early in development and remain hidden until late-stage compliance testing. This webinar will focus on how engineers can use EMC pre-compliance testing as a practical design and diagnostic tool rather than a pass/fail exercise.

The session, hosted by Jeff Markham, EMC principal engineer at Element Materials Technology, will explore what pre-compliance testing can and cannot predict; common EMC failure modes observed during early development; and how test setup, correlation, and engineering judgment directly influence results. Attendees will gain insight into how PCB layout, grounding strategy, cabling and switching architectures affect EMC behavior long before formal compliance testing begins.

Learn how early diagnostics can uncover hidden risks, reduce late redesigns and improve overall EMC robustness. This webinar is intended for engineers looking to make informed EMC decisions earlier in the design cycle.

Five key learning points for delegates:

• What EMC pre-compliance testing realistically reveals, and where its limits are.
• Common design-level causes of EMC failures seen during development.
• How test setup and correlation affect the quality of EMC insight.
• Practical techniques for identifying EMC risk early in design.
• When pre-compliance testing is sufficient and when deeper diagnostics are needed.

REGISTER NOW
Listen in and take the opportunity to ask questions along the way, on March 11, 2026, at 11:00am EST / 4:00pm GMT / 5:00pm CET.

Register for the webinar here.

The GCAR 6283 runs on embedded hardware using the QNX real-time operating system. Unlike traditional interface cards or PC-dependent systems, communication, diagnostic and simulation tasks are executed directly on the hardware. This enables functions such as residual bus simulation, parallel single-ECU testing and high-performance flashing of multiple control units without relying on a host PC.

The company says the system is designed for development environments as well as production, end-of-line (EOL) and run-in testing applications where high levels of parallel testing are required.

The tester is built on a modular backplane architecture that allows flexible configuration through plug-in modules. Supported vehicle communication standards include CAN FD, LIN, FlexRay and automotive ethernet, including 100BASE-T1, 1000BASE-T1 and 10BASE-T1S. Support for CAN XL and multigigabit automotive ethernet is planned as part of future expansions.

In addition to bus interfaces, the system provides a range of digital and analog I/O options for functions such as trigger signals, PWM, SENT and other test tasks. Onboard firmware supports features including end-to-end security functions (checksums and message counters), SecOC, network management and diagnostic protocols, allowing time-critical operations to be processed locally on the hardware.

This architecture enables complex test scenarios such as gateway simulation, parallel flashing operations and advanced residual bus simulations on a single standalone system. For trace data capture, the GCAR 6283 can be expanded with an integrated M.2 SSD.

For integration into automated test environments, Göpel Electronic provides a C-based programming interface (G-API) as well as a LabVIEW library. The system connects to a host PC via a pluggable interface card supporting 1Gbit ethernet or 5Gbit USB.

Residual bus simulations can be configured using Göpel’s Net2Run software toolchain, which derives AUTOSAR-compliant configurations from data formats including ARXML, FIBEX and DBC before deploying them to the hardware.

One of its key uses is demonstrations of technology solutions with R&S partners. For example, a test system that combines EMC receivers and automation software from Rohde & Schwarz with the AIP EMC Chassis Dynamometer enables vehicle manufacturers and Tier 1s to evaluate the EMC performance of their designs under realistic operational conditions. AIP has enhanced this system with R&S radar target simulators to also provide vehicle-in-the-loop testing of radars in a controlled environment. The Osaki office is near AIP’s new facility, enabling fast servicing and turnaround time for AIP.

Rohde & Schwarz is expanding its collaboration with Granite River Labs (GRL) and Analog Devices (ADI) to support in-vehicle network compliance testing in Japan. GRL, a provider of compliance testing and certification services for standards such as multigigabit ethernet and the Automotive SerDes Alliance, has a long history of using Rohde & Schwarz test equipment. ADI, a global semiconductor supplier, is working closely with Rohde & Schwarz worldwide to promote adoption of the emerging OpenGMSL standard through the OpenGMSL Association.

The collaboration is supported by Rohde & Schwarz Japan’s expanded facilities and the availability of leading-edge oscilloscopes and vector network analyzers, designed to ensure fast and reliable standards-compliant testing, including solutions tailored for the Japanese market. This will accelerate testing processes and facilitate the building and delivery of OpenGMSL-based solutions. The availability of local expertise and instruments is considered critical in supporting the global automotive ecosystem.

In another partnership, IPG Automotive is working with Rohde & Schwarz to integrate automotive radar hardware-in-the-loop testing from the proving ground into the development lab. The collaboration combines IPG Automotive’s CarMaker simulation software with Rohde & Schwarz’s scalable AREG800A radar target simulator, the R&S QAT100 advanced antenna array and the compact R&S RadEsT target simulator.

This combination provides OEMs and Tier 1s with the ability to simulate ADAS/AD scenarios, including those defined in Euro NCAP, in a controlled, safe, time-efficient and cost-reducing environment. In the newly established office, both companies jointly set up and demonstrate their HIL systems alongside the development of local traffic scenario simulations specific to Japan.

The automotive industry is actively exploring non-terrestrial networks (NTNs) to provide ubiquitous wireless connectivity for always-connected vehicles. The capabilities of chipset developer MediaTek’s latest NR-NTN device have been demonstrated using the Rohde & Schwarz CMX500 radiocommunication tester, a versatile solution for testing various NTN technologies including NR-NTN, NB-NTN and Direct-To-Cell (D2C, DTC). The CMX500 offers multiband and multi-orbit support, along with a dedicated NTN workspace for visualizing deployed networks and their parameters.

Rohde & Schwarz leverages its wireless and automotive expertise to help navigate the challenges associated with NTN, identify key vehicle components and explain the role of testing in creating NTN-enabled vehicles. With the opening of the hub, the global partnership between MediaTek and Rohde & Schwarz, which already covered Europe, North America and China, has now been expanded to include Japan.

The office in Osaki will facilitate a greater number of projects for Japanese automotive partners, including faster support for local NTN projects with MediaTek. The R&S CMX500 empowers customers in Japan to test and optimize the entire NTN integration chain – from chipsets and modules to antennas, TCUs and vehicles – and validates NTN vehicle connectivity tailored to the Japanese market.

Naoshi Saito, general manager of Rohde & Schwarz Japan, commented, “We are very proud of our new facility in Osaki, and we invite the Japanese automotive community to make the most of this resource and the talented staff who work here.”

In related news, Rohde & Schwarz and MediaTek partner to advance 6G waveform testing

Voltage spikes can be triggered by fast switching operations and amplified by inductances, potentially damaging or destroying downstream components. The new PMx pulse load resistors from Isabellenhütte – starting with the PMT (2817) size – safely dissipate these peaks. Based on Isabellenhütte’s SMD (surface mount device) shunt technology, the PMx series is not intended for precision measurement but instead for damping voltage spikes.

The PMT design follows the Isa-Plan principle: a copper substrate carries a foil made of Isabellenhütte’s proprietary Noventin resistive material. Its high specific resistance enhances pulse load capacity. Voltage peaks are temporarily stored in the resistive material and dissipated as heat through large copper terminals into the PCB.

Depending on the pulse energy, one or more resistors may be required. Multiple resistors can be configured in parallel or series arrays to evenly distribute the load. The number and configuration depend on expected pulse loads, available PCB space and desired resistance values.

In a snubber circuit consisting of a resistor and capacitor, PMx resistors are ideal for use in e-fuses – resettable electronic fuses found in the power supply for a vehicle’s cigarette lighter. When excessive current is drawn, the e-fuse disconnects to protect connected devices. The rapid disconnection activates the snubber circuit. The capacitor initially absorbs the pulse load and discharges through the pulse load resistor, which converts the energy into heat and dissipates it via copper terminals into the PCB.

All resistors in the PMx series are tested in accordance with the AEC-Q200 automotive standard. Within this series, the PMT is currently available in size 2817 with a value range from 50mOhm to 2.5Ohm (R050, R500, 1R00 and 2R50). The PMT is currently in the final phase of the qualification process, with series production scheduled to start at the end of March 2026. In addition to the values listed in the data sheet, customer-specific variants can also be realized within this range. Furthermore, other sizes are available on request: the feasibility of the PMS in 2512 has already been tested and can be implemented at short notice as existing equipment from measurement shunt production can be used. The PMP in size 2010 is also available as an additional option.

According to Isabellenhütte, PMx pulse load resistors are easy to integrate into PCB designs. For higher pulse loads, Isabellenhütte offers support in selecting the appropriate number and type of resistors, as well as in dimensioning, configuration and design-in. Upon request, thermal simulations can be performed to assess heat development and dissipation.

Learn about Stellantis’ HIL testing of ECUs, which it now designs in-house for the first time, in the November edition of ATTI 

Among the disruptive forces that are reshaping the automotive industry, electrification is entrenched and unrelenting. Market demands as well as safety and environmental legislation are calling for all cars – from entry-level to premium models – to become smarter, more assistive, more connected and sustainability conscious. To deliver these values, car makers are adding more sensors, computing power and communication capabilities, and electrifying more subsystems, from water pumps and power steering to the entire drivetrain.

It’s a trend that presents opportunities for electronic component manufacturers and assembly builders in the automotive supply chain. Among the challenges, the industry’s high-quality expectations and unit-volume demands call for test capabilities that are fast and extremely accurate, and able to correctly identify good units and any that have defects. This needs to be accomplished with minimal errors or time-consuming rechecking to rectify false NG results.

Improving tests of advanced electronics  

Contact test solutions for advanced equipment using probes could prevent suppliers from meeting their objectives, as test contact points are becoming smaller, more closely spaced and more difficult to reach with conventional sprung test probes (Figure 1).

Furthermore, connecting with the DUT at a single point creates an unreliable solution. All types of electronic devices are affected, from semiconductor wafers to ECU modules, as component geometries are being reduced and PCB assemblies are more densely populated. Also, intricately designed vibration-proof connectors used within the automotive industry present difficulties for probes to achieve contact when placed on the test fixture (Figure 2).

Problems with sprung test probes or pogo pins are already common. The pins often fail to make proper contact with the test point. Based on actual research, only 80% of occasions when tests are performed using standard pogo pins result in the DUT being correctly classified. Such errors result in high false NG rates that require investigation and re-testing. In addition, the typical lifetime of a pogo pin can be about 100,000 cycles. At automotive mass-production volumes, this can demand frequent stoppages for replacement. Inaccurate results and frequent stoppages both impair productivity and cause delivery delays.

Also, the contact resistance due to conventional pogo pin structure can be inconsistent and is not usually less than 70mΩ, which can prevent testing of assemblies where contact resistance needs to be low. A generally accepted practicable minimum diameter for conventional sprung pins is about 0.35mm. Reducing the size can prevent reliable contact with test points as the probes can become fragile, leading to more frequent malfunctions and breakages. And yet, smaller test pins are required to meet future demands. An alternative is needed to ensure efficient, fast and accurate contact testing.

Pin limitations

Conventional pogo pins are carefully designed to possess compliance that allows tolerance for a small amount of positioning error, as well as spring force to press against the DUT test point and ensure a robust electrical connection with low ohmic resistance. However, the mechanism adds complexity to the design and seizing or other malfunctions are possible as the DUT is placed on the test fixture. The pin can break or the spring may fail if positioning error or force is excessive. Further reducing the mechanism size to permit closer positioning needed to test densely populated boards results in the pin being more fragile and more easily broken.

Creating an alternative that overcomes these limitations while also supporting the drive toward smaller geometries is not easy or trivial. A suitable pin must provide adequate compliance to let the pin find its place against the test point as well as ensuring adequate and consistent contact force. At the same time, durability needs to be improved to minimize stoppages to replace broken pins and prevent false NG results that can result from poor electrical contact and inconsistent contact resistance.

A new type of test pin made with a specially developed electroformed (EFC) metal alloy and fabrication process now presents a solution to meet these demands. The custom material provides mechanical properties comparable to 304-grade stainless steel (SUS304/SS304) and meantime electrical properties achieving great conductivity at copper level. The combination of alloy properties and dedicated pin design (Figure 3) enable one-piece pins that eliminate the size restrictions and potential for seizing associated with the conventional spring mechanism.

Optimized electrical parameters 

The pins enable test engineers to create high-reliability test fixtures with a pitch down to 0.175mm. Because the pins have been shown to make proper contact with the test point on over 99.8% of test operations, the risk of false NG results from poor pin contact is greatly reduced. Also, with a lifetime easily reaching 500,000 cycles depending on application and design, their longevity improves efficiency and reduces stoppage time. The one-piece design ensures consistent electrical parameters and extremely low-contact resistance, typically about 30mΩ, which is suitable for testing products like OLED panels. Moreover, flexibility to optimize all aspects of the pin size, shape and tip design mean the pin properties can be adapted for a wide variety of applications.

EFC pins are suited to pin blocks and complete custom sockets for board-level testing and are also used in optimized fixtures for IC and other component testing, or even device test. They have been designed for testing high-end modules with high transmission speeds, as well as high-power electronics at levels much above 2A per pin for unique bundle structure, meantime reaching the highest testing durability.

There is also an off-the-shelf product. The unique test socket for USB Type-C connections combines EFC pins with resin pin tips and a special floating head mechanism that enables 1° of tolerance in X-Y positioning (Figure 4). The floating head ensures fast and faultless insertion to avoid stoppages when used in test equipment while the special internal pin structure extends the endurance of testing sockets compared to existing means.

Conclusion

Pogo pins have a long and distinguished record in the history of electronics testing and can continue delivering high levels of performance in many applications. At the cutting edge, however, the geometries of the latest components and assemblies are becoming too small for conventional pins.

Creating a suitable solution has demanded innovation both in materials science and electroforming production processes. New one-piece EFC pins allow test-point spacing as small as 0.175mm, with lower contact resistance than pogo pins, and enhance positional accuracy, resilience and reliability. Using custom shapes and tip profiles, these pins can reach difficult areas such as inside complex connectors, and can meet demanding applications such as high-frequency or high-current testing. Product manufacturers can experience fewer false NG calls and fixture repairs, raising efficiency, productivity and delivery performance.

Look out for a feature in the November issue of ATTI on how Stellantis ensures the robustness, reliability and compliance of EE components and systems through systematic validation and virtualization. Read the September edition for FREE here