How to identify electronic components that meet automotive-grade standards?

Anything related to cars must have automotive grade. What is so special about automotive grade?

The prices of automotive electronics are skyrocketing today, and the reason is nothing more than “automotive grade”, but what exactly is this automotive grade that everyone is talking about?

As the name implies, the car-grade standard is a kind of automobile standard that complies with the regulations on automobile standards legislated by various countries, and the standards of various countries are different. For example, in the United States, car navigation requires AECQ certification. Taking car navigation as an example, a high-performance processor is required first. The car-grade control unit specializes in processing CAN bus information and control logic to ensure the reliable operation of the system. Then there is the decoding of high-definition audio and video hardware, the decoding of audio and video files, and the adjustment of the front and rear seat sound fields and the left and right balance positions. At the same time, it must be compatible with the original car's CAN bus protocol and the original car's wiring harness, match the original car's protocol, support the original car's steering wheel control, and display the vehicle's driving information normally. Of course, fast positioning and navigation are also required to support the installation of gyroscope functions. EMC electromagnetic compatibility performance must meet standards, etc.

In summary, automotive grade is actually a set of hardware specifications and standards, which is an extension of industrial grade. Products that meet the above standards can be called automotive grade. The high standards of automotive grade automotive electronic components can better meet the needs of the automotive industry.

The automotive-grade standard is the AEC-Q series standard. AEC-Q100 applies to chips, AEC-Q101 applies to discrete semiconductor devices, AEC-Q102 applies to discrete optoelectronic devices, AEC-Q103 applies to MEMS devices, AEC-Q104 applies to multi-chip modules, and AEC-Q200 applies to passive components.

Generally speaking, automotive-grade electronic components can usually be divided into four levels according to the application scenarios: consumer-grade, industrial-grade, automotive-grade, and military-grade. The requirements are military-grade>automotive-grade>industrial>consumer-grade.

Automotive electronic components have different requirements for the external working environment, such as temperature, humidity, mildew, dust, water and harmful gas erosion, depending on the installation location, but are generally greater than consumer grade.

Take the requirements for Renesas' automotive-grade chips as an example: the chip is required to be able to work normally in an ambient temperature of -40℃~75℃, humidity of 95%, and an electrostatic environment of 15~25KV. It is also required to have a shelf life of 20 years and must not break down during the shelf life. The product defect rate must be less than one in 1 million, which is almost 0.

In addition to the environment, the requirements for reliability and consistency of automotive electronics are generally greater than those of industrial grade.

Its testing conditions are more standardized and stringent than those for consumer-grade and industrial-grade electronic components. The stringent automotive-grade standards can ensure that a car composed of a large number of ECUs and tens of thousands of electronic components has a long life cycle and high reliability during use.

Reliability: The ability to perform without error under specified conditions.

The design life of automobiles is about 15 years, which is much longer than the life of consumer electronic products. At present, the electrification level of vehicles is very high. In particular, the control systems of electric vehicles are equipped with many ECU devices, each of which is composed of many electronic components. In order to ensure that the vehicle achieves a high reliability, the requirements for each part of the control system are very high.

Consistency: Parts remain consistent.

For complex automotive products, components with low reliability and poor consistency undoubtedly mean huge safety risks, so PPM (parts per million) is often used to describe the requirements for automotive parts.

Today's cars are mass-produced, with manufacturers producing hundreds of thousands of a given model of vehicle per year. Therefore, the requirements for consistency in product quality are very high. For automotive products with complex parts and components, the use of electronic components with poor consistency will lead to safety hazards in the entire vehicle.

Let’s look at some other requirements.

Manufacturing process

The requirements for automotive product manufacturing processes. Although automotive parts are constantly developing towards miniaturization and lightweight, compared with consumer products, the size and power consumption can be relatively relaxed. Generally, larger packages are used to ensure sufficient mechanical strength and comply with the manufacturing processes of major automotive suppliers.

Product Life Cycle

Although the price of automobile products has been continuously reduced in recent years, automobiles are still durable and large-sized commodities, and the supply of after-sales parts must be maintained for a long time. At the same time, the development of an automobile part requires a lot of verification work, and the verification work brought by the replacement of components is also huge, so vehicle manufacturers and parts suppliers also need to maintain a stable supply for a long time.

Standards and Verification

It seems that meeting the requirements of automotive products is indeed complex, and the above requirements are for automotive parts (for electronic components, it is the system), so it becomes very difficult to convert them into the requirements of electronic components. To solve this problem, some standards naturally emerge, and the most recognized one is the AEC standard:

AEC Q100 Requirements for Active Device Components

AEC Q200 Requirements for Passive Devices

Any choice has two sides. The requirements are higher than military grade, but the cost is lower than that, which increases the difficulty of designing automotive-grade products. The first difficulty is that automotive-grade development and verification are expensive and have high barriers to entry. Secondly, the selection difficulties caused by the complexity of parts often lead to the abandonment of some highly integrated solutions. Finally, the production cycle of automotive-grade chips is very long, and a lot of verification work will affect the speed of product launch. Most chip manufacturers choose to apply their products to the automotive market only after the consumer electronics market matures.

The requirements for automotive-grade chips are already so high, and the on-board power supplies and charging pile power devices used in new energy vehicles are even higher.

I guess many people will say that there are many corporate standards for vehicle manufacturers. In fact, some vehicle manufacturers do have relevant general reliability requirements, but they assess a complete automotive component (a system composed of electronic components), rather than directly targeting the requirements of the electronic components that make up these components (resistors, capacitors, transistors, chips, etc.). Although its requirements can be used as a reference for the selection of lower-level components, it is still very inappropriate for electronic component testing.

Vehicle regulations verification

In the work of car manufacturers, it is inevitable to use some electronic components that are not AEC Q100/200 certified. Many car factory personnel will want to conduct some reliability verification to verify whether it meets the vehicle regulations.

I personally think this method is not very effective, because these tests are only necessary but not sufficient tests. They can only be used to deny the availability of the device, but cannot confirm that it can be used.

The reason is simple, the sample size is too small and the test items are not sufficient. For mass-produced components such as semiconductors, it is very unreliable to determine their reliability through testing a small number of samples. Here we can also take a look at the main certification test items conducted by AEC Q100, and we can see the difference.

Which standard is more demanding?

Which one has higher requirements, automotive standards or industrial standards? It is generally believed that the order of standards is military industry > automotive > industrial > consumer electronics. But I personally cannot fully accept this order. Industry is a very wide range, and the environment and reliability requirements encountered are also very different. It can be imagined that the reliability requirements of a large industrial equipment will never be lower than those of an automobile. (For example, the key equipment of a large power plant), and at the same time, the harshness of the environment may also far exceed the requirements of automobiles. It cannot be simply said that the requirements of industrial standards are lower than those of automobiles.

Disadvantages of using automotive parts

Any choice cannot have only advantages and no disadvantages. What are the disadvantages of using automotive electronic components? First of all, they are expensive. The system requirements are high, the development and verification costs are high, and the low production volume leads to a much higher cost than consumer electronics. The relatively high threshold also leads to a large sales premium.