Chips in automotive manufacturing The role of semiconductor testing in the automotive industry

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In modern hybrid and battery-electric vehicles, an increasing amount of electronics is being installed. This leads to more complex test scenarios for semiconductor testing. Also, with respect to higher voltages and faster switching times, the limits of testing are quickly reached.

The market for testing automotive semiconductors is growing organically as chip manufacturers produce increasingly larger volumes for a variety of automotive applications. Manufacturers of automated test equipment (ATE) are adjusting to ensure that their systems can process components ranging from display drivers for fully electronic dashboards to silicon carbide power transistors (SiC) for traction inverters.

The use of semiconductors in the automotive industry is increasing. Currently, automakers install about 8 to 10 percent of all produced semiconductors. This proportion is expected to rise as the market share of electric vehicles increases and automakers equip their vehicles with increasingly sophisticated Advanced Driver Assistance Systems (ADAS). This trend is also driven by the rising proportion of software in vehicles aiming for higher levels of autonomy, as well as the shift of semiconductors, previously used mainly in luxury brands, to vehicles in the middle and lower market segments.

Increasing semiconductor content in hybrid and EV drivetrains.

According to Gartner, the global market for semiconductors in the automotive industry is projected to grow from 67.5 billion USD in 2022 to 155.4 billion USD by 2032. This rapid increase is justified by software-defined vehicles, which will make up 90 percent of all produced cars (up from 4.1 percent in 2022), and by the widespread adoption of level 2 autonomous vehicles, increasing from 4.2 million in 2022 to 33.5 million in 2032. Level 2 implies partial automation of driving where an ADAS system can handle steering and speed control, but a driver must be present behind the wheel to take control of the vehicle at any time. The share of vehicles with internal combustion engines will drop below 60 percent, being replaced by hybrid and EV drives, leading to an increasing share of semiconductors.

Even in the automotive industry, there are fluctuations in demand. At the peak of the COVID-19 pandemic, demand was very high and supply was limited. However, demand has since stabilized, supply chains have been replenished, and automakers have established secondary sources for many of the required chips.

Increased demands on testing systems

Traditionally, semiconductors had several main applications in automotive manufacturing: They were used for engine control, as well as to manage transmissions, power windows, power steering, power brakes, seat heaters, and door locks. Microcontroller units (MCUs) took on the control functions and managed the sensors and actuators, which were distributed throughout the vehicle in either a distributed or zonal architecture and interconnected via a CAN bus.

In this scenario, a semiconductor test system capable of testing consumer-class MCUs could easily handle MCUs for the automotive industry. The main difference was that they met the quality standards of the automotive industry and allowed testing of ICs over a broader temperature range. Additionally, the standard battery voltage was 12 V, so most available power supplies and analog testers were sufficient.

Today, technology has evolved, and cars contain many different devices with higher complexity and voltages. Traditional functions such as engine and transmission controls are still present, but the requirements have increased as automakers strive for greater efficiency and lower emissions in combustion engines.

Stricter quality aspects for microprocessor units.

In this scenario, High Performance Computing (HPC) is making its way into the vehicle. Commonly associated with servers, HPC allows for the implementation of increasingly sophisticated ADAS functionalities that perform safety-critical and vital functions. To implement HPC capability, automakers are shifting from a decentralized to a centralized architecture, enabling extensive data transmission from sensors distributed throughout the vehicle to a central electronic control unit (ECU). This requires powerful microprocessor units (MPUs), which in turn need high-speed interfaces to the vehicle network.

MPUs in vehicles must meet stricter quality aspects compared to consumer ICs. This typically increases the test coverage, involves outlier detection, and introduces a burn-in test sequence. Furthermore, testing over a wide temperature range from -40 to 125/175 °C is mandatory.

Increasing voltages in vehicles.

Higher voltages in vehicles, resulting from advancements in automotive electronics, include the transition from 12-volt to 48-volt architectures. This higher voltage allows for the operation of adjustable seats, power windows, heating systems, and even mild hybrid drive motors. Manufacturers of automated test equipment (ATE) are developing instruments capable of handling higher voltages and currents to test the ICs that enable these higher voltage architectures.

Hybrid electric vehicles (HEVs) and fully electric vehicles (EVs) pose different demands on testing as they require not only MCUs and other low-voltage components, but also battery management systems (BMS) and high-voltage power modules. Hybrid electric vehicles present some testing challenges, but they operate at relatively low voltages compared to fully electric vehicles, and their battery-powered range is typically about 40 to 60 kilometers.

In contrast, fully electric vehicles with several hundred kW of power contain converter electronics that can operate at up to 800 V. In this respect, vehicle electronics are becoming similar to the electronics used in rail vehicles, wind turbines, and solar power plants, requiring high-performance testing methods.

The uniqueness of silicon carbide (SiC) technology

For EV traction inverters, automakers are increasingly relying on SiC components due to their high-voltage capability and efficiency. SiC components can increase the battery range of a high-quality electric vehicle by an estimated 7 to 15 percent. Testing SiC technology can prove challenging. Regenerative braking can stress the SiC components.

Automakers require effective testing equipment to ensure that components function properly. Particularly critical is the short circuit test, in which the component must be shut off quickly. During such tests, the testing system must protect the device under test (DUT), the handler, the probe card, and the test equipment itself throughout the entire testing process to prevent damage to the system.

Semiconductor testing companies need to be capable of covering the entire spectrum of components—including DRAMs, flash memory, MCUs, display drivers, and power supply ICs—for both traditional and new automotive applications. They can transfer their capabilities from commercial applications to automotive components, with the main differences being the temperature range and the higher quality requirements.

Modular ATE architecture allows for more testing

Conventional MCUs and similar components require high-quality, cost-effective tests with high throughput. A modular ATE (Automated Test Equipment) architecture that allows for flexible reconfiguration can accommodate digital, high-performance analog, and power mixed-signal functions, enabling chip manufacturers to test a wide range of ICs, including advanced automotive ICs for ADAS (Advanced Driver-Assistance Systems) applications.

ADAS (Advanced Driver-Assistance Systems) require not only HPC (High-Performance Computing) MCUs/MPUs but also inputs from cameras, radar, infrared, and other sensors. Additional automotive ICs that require efficient testing solutions are used in applications such as airbag deployment and anti-lock braking systems, where intensive testing is essential for safety reasons. Here too, a flexible testing platform is the ideal approach to ensure that these testing requirements can be met, as well as for RF-based ICs ranging from radar sensors to components of infotainment systems.

Vehicles will continue to incorporate a multitude of components in the future, including conventional MCUs for dashboard functions, and Display Driver Integrated Circuit (DDIC) components for fully electronic dashboards. Testing solutions must be capable of meeting DDIC testing requirements within a temperature range of -40 to 175°C ( -40 to 347°F.) ICs that require higher voltages and currents than standard automotive components necessitate test capabilities up to 2,000 V or >150 A using parallel-connected power VI sources.

High accuracy is also a crucial parameter for the testing of the latest generation of Battery Management System (BMS) components. BMS are responsible for battery charging, protection, cell balancing, and estimating the state of charge of the battery. Battery management systems pose a significant challenge for testing as cell stacks contain more cells per BMS chip, and accurate voltage monitoring becomes increasingly important to maximize usable capacity and extend cell life. To support BMS tests, ATE systems need to be able to deliver voltages up to 160 V and have the capability to provide highly accurate supply and measurement accuracies of <100 µV at high floating voltages.

A conclusion: Increasing demands on testing equipment

Testing equipment for high-performance ICs, such as those used in drive inverters, requires even higher voltages, currents, and capacities. The market for High-Energy (HE) testing equipment has been relatively small so far, focusing on railroad, wind turbine, and similar applications. However, the market for electric vehicles will increase the demand for HE testing equipment that is suitable for operation at 400 V/800 V.

To meet the growing market for power semiconductors, which utilizes a range of efficient power components, ATE solutions are required that can efficiently and effectively test SiC (Silicon Carbide) and GaN (Gallium Nitride) implementations. These materials are becoming increasingly popular as governments and industries in the automotive sector and many other applications aim for net-zero emissions.

Partnering with chip manufacturers to identify and develop the optimal solution for testing requirements is particularly important in the automotive industry, as the use of electronics in vehicles continuously evolves. This enables ATE providers to recognize new technologies and develop the necessary solutions to test these accurately, quickly, and cost-effectively. Traditional electronic ICs continue to be used, but new innovative products, from MCUs for HPC to power modules for use in traction inverters, are increasingly gaining importance.

Furthermore, the increasing electrification leads to a growing demand for semiconductor testing to meet the high standards, rapid growth, and complexity involved. The development of universal solutions that can be adapted to specific application requirements through user-friendly software is key to success for testing solutions in the automotive sector. (heh)

*Toni Dirscherl is responsible for Business Lead Power / Analog / Control at Advantest

This article first appeared on our sister website www.ElektronikPraxis.de (German Language)