What you’ll learn:
- The types of devices being deployed in cars and how they differ in functionality.
- Why each device type requires a different test technique.
- Determining the best approach for the specific application.
The automotive semiconductor test market is growing organically as chipmakers produce higher volumes of devices serving an array of automotive applications. Moreover, as the technology advances, the range of applications for automotive-grade semiconductors is evolving in kind. Automated-test-equipment (ATE) manufacturers are adapting to ensure their systems can handle devices ranging from display drivers for all-electronic dashboards to silicon-carbide (SiC) power transistors for traction inverters.
The automotive industry’s use of semiconductors is on the rise, with carmakers now consuming about 8% to 10% of all semiconductors produced. This percentage is expected to ramp up as electric vehicles increase market share and as automakers outfit their vehicles with increasingly sophisticated advanced driver-assistance systems (ADAS).
The trend is further driven by the increasing software content in vehicles to achieve higher levels of autonomy and by the migration of semiconductors once used primarily in luxury brands into mid-range and low-end cars over time.
According to Gartner, the worldwide automotive semiconductor market will grow from $67.5 billion in 2022 to $155.4 billion in 2032. By then, software-defined vehicles (SDVs) will surpass 90% of the total vehicles produced (up from 4.1% in 2022), unit production share of vehicles with internal combustion engines will drop below 60%, and autonomous vehicles above level 2 will reach 33.5 million, up from 4.2 million in 2022. (Level 2 implies partial driving automation whereby ADAS can handle steering and speed control, but a human must remain behind the wheel and be prepared to take control at any time.)
The automotive industry also presents demand fluctuations. At the height of the COVID-19 pandemic, for example, demand was aggressive and supplies were tight. Now, however, demand has moderated, supply chains have filled, and automakers have established second sources for many of their required chips.
Expanding Applications of Automotive Semiconductors
Semiconductors have traditionally served a few primary applications in the automotive space. They found use in engine control as well as the control of gearboxes, power windows, power steering, power brakes, seat heaters, and door locks. Microcontroller units (MCUs) typically handled the control functions, and they managed the sensors and actuators arranged in a distributed or zone architecture throughout the vehicle interconnected via a controller-area network (CAN) bus.
For this scenario, a semiconductor test system that could test consumer-grade MCUs should easily handle the automotive MCUs. The key difference between them was the latter needed to meet automotive quality standards and operate over the automotive temperature range. In addition, the standard battery voltage was 12 V, so most available power and analog tester resources would suffice.
Today, though, technology has evolved, and cars contain many different devices of heightened complexity and higher voltage ranges. The traditional functions such as engine and gearbox control remain, but their requirements have become more stringent as automakers pursue higher efficiencies and, for internal combustion engines, reduced emissions.
Integrating High-Performance Computing in Automotive ADAS Systems
In this new scenario, high-performance computing (HPC) typical of servers is moving into cars to implement increasingly sophisticated ADAS capabilities that perform safety/life-critical functions. To help implement the HPC functionality, automakers are moving from a distributed to a centralized architecture.
That requires massive data transfer from sensors throughout the vehicle to a central electronic control unit (ECU) incorporating a high-performance microprocessor unit (MPU), which in turn necessitates high-speed automotive network interfaces. Automotive MPUs, compared to consumer devices, must fulfill more strict quality aspects. Therefore, the test coverage typically is increased, outlier detection is applied, and a burn-in test flow gets introduced. In addition, testing across a wide temperature range from −40 to +125/175°C is mandatory.
Evolving to Higher-Voltage Architectures in Automotive Electronics
Other factors resulting from the evolution of automotive electronics include the move from 12- to 48-V architectures to power adjustable seats, windows, heaters, and even mild-hybrid traction motors. ATE makers are developing higher-voltage and -current instruments to test the devices that enable these higher-voltage architectures.
Hybrid electric vehicles (HEVs) and fully electric vehicles (EVs) add further test considerations, requiring not just MCUs and other low-voltage components, but battery-management-system (BMS) devices and high-voltage power modules as well. HEVs present some test challenges, but they operate at comparatively low voltages compared with EVs, and their battery-powered driving range is only about 40 miles.
In contrast, EVs delivering hundreds of horsepower incorporate converter electronics that can operate up to 800 V. In this respect, vehicle electronics is starting to resemble the electronics used in railway, wind-turbine, and solar-park applications, requiring high-power test methods.
SiC Technology for High-Efficiency EV Traction Inverters
For EV traction inverters, automakers are increasingly turning to SiC devices because of their high-voltage capabilities and efficiency. SiC devices can extend the battery range of a high-end EV by an estimated 7% to 15%.
However, testing SiC technology can prove to be challenging. Operations such as regenerative braking, for example, can stress the SiC devices—automakers need effective test equipment to ensure the devices work. Of particular importance is short-circuit test, which requires a fast device turn-off device. The test system must protect the device under test (DUT), the handler, the probe card, and the tester itself throughout 100% device test.
Comprehensive Testing Solutions for Automotive Semiconductor Devices
Semiconductor test companies must be able to cover the gamut of devices—including DRAM, flash memory, MCUs, display drivers, and power devices—for both traditional and new automotive applications. They can leverage their capabilities for applications ranging from commercial to automotive devices, where the key differences include temperature range.
Traditional MCUs and similar components require high-quality, cost-effective test at high throughput. A modular ATE architecture that enables flexible reconfiguration can accommodate digital, high-performance analog, and power-mixed-signal capabilities. In turn, chipmakers can test a wide range of devices, including advanced automotive devices for ADAS applications.
In addition to requiring HPC MCUs, ADAS require inputs from cameras, radar, infrared, and other sensors. Other automotive devices requiring effective test solutions find use in applications ranging from airbag deployment and antilock braking, where test is vital due to safety aspects. Again, a flexible test platform is the ideal approach to ensure that these test requirements can be met, as well as those of RF-based devices, ranging from radar sensors to infotainment system components.
Vehicles will continue to incorporate a variety of other devices, including traditional MCUs for dashboard functions, with all-electronic dashboards also requiring display-driver integrated-circuit (DDIC) devices. Test solutions must be able to handle DDIC test requirements across the −40 to +175°C temperature range. Devices that require higher voltages and power levels than standard car components call for test capabilities up to 2,000 V or >150 A using ganged power VI setups.
High accuracy is also an important parameter for testing the latest generation of battery-management-system (BMS) devices. BMSs perform battery charging, protection, cell balancing, and battery state-of-charge estimation.
Such BMSs present significant test challenges as cell stacks present more cells per BMS chip and accurate voltage monitoring becomes increasingly important to maximize usable capacity and extend cell life. To support BMS test, ATE will require high-voltage capabilities up to 160 V and the ability to provide highly accurate force and measurement performance <100 µV at high floating voltages.
High-Energy Test Solutions for EV Power Devices and Inverters
Test equipment for high-power devices such as those used in traction inverters requires even higher voltage, current, and power ratings. The market for high-energy (HE) test equipment used to be relatively small, focusing on railway, wind-turbine, and similar applications. However, the EV market is poised to expand the requirements for HE test equipment that can handle 400/800-V operation.
Addressing the growing market for power semiconductors deployed for a variety of efficient power devices requires ATE solutions that can efficiently and effectively test SiC and gallium-nitride (GaN) implementations. These materials are growing in popularity as governments and industry pursue net-zero carbon emissions across the automotive industry, as well as many other applications.
Conclusion: Chipmaker Partnerships and Augmented Semi Test
Partnering with chipmakers to determine and develop the optimal solution for their test demands is particularly vital in the automotive industry due to the continuously evolving electronics usage in vehicles. This enables ATE providers to see new technologies coming as well as develop the solutions necessary to test them accurately, quickly, and cost-effectively. Traditional electronic devices continue to find use, but new innovative products ranging from MCUs for HPC to power modules for traction inverters are becoming increasingly important.
In addition, increasing electrification drives the need for more semiconductor testing to address high-demand, high-growth, complex requirements. Creating universal solutions that can be customized with user-friendly software to meet specific application needs is key to success in the automotive test space.