Governments around the world are taking steps to promote electric vehicles
Automotive OEMs Require AEC-Q101 Compliant Semiconductors
Engineers, Need to Understand MOSFET Data Sheets


Major governments around the world are pushing for the spread of electric vehicles.

Starting this year, the European Union (EU) has set the average carbon dioxide emissions standard for cars sold by automobile manufacturers at 95g per km, and for each 1g exceeding this standard, a fine is imposed equal to the amount of excess emissions x 95 euros x the number of newly registered vehicles.

It is nearly impossible to achieve this figure unless the number of electric vehicles produced increases. In addition, although there are differences between countries, sales of internal combustion engine vehicles are scheduled to be banned in the EU by 2040. As a result, the stock prices of electric vehicle battery companies continue to soar, and the competition for orders is proceeding at a rapid pace.

Tesla, a leading electric vehicle manufacturer in the United States, has begun full-scale production of mass-market electric vehicles, and China has extended the expiration date of electric vehicle subsidies by two years from the end of 2020 to the end of 2022 to expand the distribution of electric vehicles.

These regulations and support are intended to protect the environment by reducing exhaust emissions and slowing global warming, while also allowing domestic companies to take the lead in the nascent electric vehicle industry.

Electrification of vehicles is not just affecting the powertrain. With the advancement of autonomous driving technology and vehicle infotainment systems, the percentage of power semiconductors installed in vehicles is steadily increasing, and this trend is expected to continue in the future.

Most automotive OEMs today require AEC-Q101 for quality assurance, i.e. safety, of discrete components.

In particular, power MOSFETs are the most widely used power semiconductor devices in today's electronics. And MOSFET data sheets provide various electrical and physical characteristics for designers. If designers do not understand them well, problems such as reduced performance of automobiles or electrical equipment, increased prices, and design errors may occur.

We met with Chang-Soo Moon, Managing Director of Infineon Korea's Automotive Business Division, and asked him about trends in automotive semiconductors and ways to improve reliability.


Q. As the percentage of electrical components installed in automobiles increases, the related market is also growing explosively. In the automotive semiconductor sector, what types of semiconductors are mainly in demand?
A. There is an increasing demand for ASIL-rated semiconductors for ISO 26262 safety standards as well as sensors related to autonomous driving technology. In particular, the demand for power semiconductors is increasing significantly as redundancy systems increase in response to fail-safe design requirements.

In recent years, as electric vehicle systems pursue greater power capacity and higher efficiency, the application of silicon carbide (SiC) MOSFETs and SiC diodes, as well as IGBTs and high-voltage MOSFETs, is increasing.

As the 48V system market grows, the adoption of medium-voltage MOSFETs and the gate driver ICs and 48V power supply semiconductors that can drive them is also increasing.


Q. What is the most important requirement for MOSFETs installed in recent automobiles?
A. The important requirements vary depending on the application. For example, in the case of electric vehicles, efficiency and power density are important, so the electrical performance of the FET is given priority.

As automotive applications requiring high-power performance are expected to increase in the future, the demand for package products with excellent heat dissipation performance is expected to increase significantly.

Additionally, reliability, which provides consistent quality power to all applications, will likely continue to be an important requirement.


Q. What capabilities should a developer have to properly understand the performance of the power MOSFET they want to use?
A. Two abilities are required. The first is the ability to interpret power systems. You must be able to understand and interpret the operating modes of power systems.

The second is the ability to understand the operation of the MOSFET and its data sheets. I believe that having a good understanding of the characteristics of the MOSFET described in the data sheet will enable loss analysis, temperature analysis, and design to prevent failure modes when applying it to the system being developed.


Q. Most automotive OEMs require semiconductors compliant with AEC-Q101 to ensure quality assurance of discrete components. What is AEC-Q101?
A. The official name of AEC Q101 is Stress test qualification for Automotive grade discrete semiconductors. In other words, the purpose of AEC Q101 qualification is a stress test to ensure the quality and reliability of power devices used in automobiles.

EC Q101 certification defines several test methods, including thermal cycle test, gate oxide stress test, wire bonding test, and ESD test.


Q. Are automotive power semiconductors suitable for use as long as they meet AEC-Q101 qualification?
A. AEQ Q101 is the quality system that most automobile companies currently apply as a minimum requirement. However, with the emergence of technologies that require high reliability, such as autonomous driving, and considering the failure in time (FIT) due to the increased use of semiconductors in vehicles, even AEC-Q101 is not a sufficient condition.


Q. How can Infineon's MOSFET simulation model improve MOSFET reliability?
A. Since the simulation model looks at electrical performance, it is not directly linked to reliability.

On the other hand, for the Level 3 MOSFET model provided by Infineon, simulation can be performed at the maximum value of Rds(on) and also by setting the operating temperature.

Since the values of Vgs(th) and Rds(on) are simulated in conjunction with the temperature change of ET, it helps to check the design margin through a simulation that assumes a worse case.


Q. Where does Infineon want to reach in the automotive power semiconductor market?
A. As a leading company with long experience in the power semiconductor field, Infineon approaches from a system level rather than individual components and discusses system requirements with customers from the early stage of development. In addition, it contributes to improving the safety of automobiles by providing highly reliable products required for automotive applications.

Going forward, Infineon will continue to understand in advance what each system in the car requires, how future trends will flow, and what power semiconductors will need to have accordingly. Based on this, we will develop leading new products and strive to meet the needs of customers who demand high efficiency and high reliability.