Compared with ordinary chips, where is the car-grade chip stronger?

The price of automotive electronic products is generally more expensive, one of the main reasons is the use of vehicle-grade electronic components, but what kind of electronic components are vehicle-grade devices? Let's first look at the differences between the application of electronic components in automobiles and the application of consumer electronics in general.

Environmental requirements

Temperature: Automotive electronics has relatively wide working temperature requirements for components, and has different needs according to different installation positions, etc., but they are generally higher than the requirements of civilian products (it is said that AEC Q100 has removed the temperature requirements of 0 °C-70 °C in the H version, because no automotive product requirements can be so low).

Example:

Engine peripheral: -40 °C -150 °C;

Passenger compartment: -40°C-85°C;

Civil products: 0 °C-70 °C.

Other environmental requirements such as humidity, mold, dust, water, EMC, and harmful gases are often higher than consumer electronics requirements.

Vibration, shock

Cars working in a moving environment will be associated with many products, experiencing more vibration and shock. This requirement may be much higher than placing products that are used at home.

reliability

To illustrate the reliability requirements of the car, let me explain it in another way:

1. Design life: The general design life of automobiles is about 15 years and 200,000 kilometers, which is much greater than the life requirements of consumer electronic products.

2. Under the same reliability requirements, the more components and links the system is composed of, the higher the reliability requirements for the components. At present, the degree of electronicity on the car is already very high, from the powertrain to the braking system, it is equipped with a large number of electronic devices, and each device is composed of many electronic components. If you simply think of them as a series relationship, then to ensure that the vehicle achieves considerable reliability, the requirements for each part of the system composition are very high, which is why the requirements for auto parts are often described in PPM (one part per million).

Consistency requirements

Now the car has entered a stage of mass production, a car can produce hundreds of thousands of vehicles in 1 year, so the consistency of product quality requirements are very high. This was quite challenging for semiconductor materials in the early years.

After all, the consistency of the process such as diffusion in the production of semiconductors is difficult to control, and the performance of the products produced is easy to disperse, and can only rely on aging and screening to complete in the early stage, and now with the continuous improvement of the process, the consistency has been greatly improved. Consistency in quality is also the biggest difference between many local and internationally renowned suppliers. For automotive products with complex composition, it is certainly unacceptable that poorly consistent components cause safety hazards in the vehicle.

Let's look at a few other requirements:

Manufacturing process

The requirements of the automobile product manufacturing process, although the parts of the automobile are also constantly developing towards miniaturization and lightweighting, but relative to consumer products, the volume and power consumption can be relatively relaxed, and the packaging generally used is larger to ensure that there is sufficient mechanical strength and conforms to the manufacturing process of major automobile suppliers.

Product life cycle

Although in recent years, the price of automotive products has been continuously reduced, but the car is still a durable large commodity, must maintain a considerable period of time after-sales accessories supply capacity. At the same time, the development of an auto part requires a lot of verification work, and the verification work brought about by the replacement of components is also huge, so the vehicle manufacturing enterprises and parts suppliers also need to maintain a long period of stable supply.

standard

In this way, to meet the requirements of automotive products is indeed complex, and the above requirements are for auto parts (for electronic components is the system), how to convert into electronic components requirements become very difficult, in order to solve this problem there are naturally some normative standards appear, more recognized is the AEC standard:

The AEC Q100 is for active device components

The AEC Q200 is a requirement for Passive Device components

Of course, I guess many people will also say that there are many OEM corporate standards. But I also want to talk about my understanding of this. The OEM I have worked for before does have standards for general reliability requirements, but it examines 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 subordinate components, but as an electronic component test, etc. it is still very inappropriate.

Verification of vehicle rules

My personal opinion is that this approach is not very effective, because these tests can only be necessary and insufficient tests. It can only be used to negate the availability of the device, not to determine its use.

The reason is simple, the sample size is too small to test the project is not sufficient. For semiconductors such as mass manufactured components, through a small number of sample tests to determine its reliability, personally think it is very unreliable, here we can also look at the AEC Q100 main certification test items, you can see the difference.

Which standard is more demanding?

Car rules and work rules, who have high requirements. It is generally believed that the order of high and low standards is military > automotive > industrial > consumer electronics. But the individual cannot fully accept this order. Industry is a wide range, and the environmental and reliability needs encountered are also very different. It is conceivable that the reliability requirements of a large industrial equipment, for example, are definitely not lower than those of a car. (such as the key equipment of a large power plant), and at the same time, the harshness of the environment may far exceed the requirements of the car, and it cannot be simply said that the requirements of the work regulations are lower than those of the car.

Disadvantages of using car rules parts

No choice can only have benefits and no harms, what are the disadvantages of using automotive electronic components?

The first is expensive, the system requirements are high, the development and verification costs are large, and the low output leads to a large increase in cost than consumer electronics. The relatively high threshold also allows for a higher sales premium.

The second disadvantage is that it is difficult to select the type. People who play electronics know that the development to today, electronic components are quite rich, do the same function of the product can have a variety of programs, complexity may vary greatly, but sometimes in order to meet the requirements of the car rules, have to give up some highly integrated programs.

There is also a more obvious disadvantage is that some product technology is backward, a large number of verification work affects the speed of new products, at the same time, the chip manufacturers' general delivery strategy is also hoping to mature in the consumer electronics market, before the product is applied to the automotive market. For example, in 2013, the ARM Cortex A9 processor used in a product developed by Xiaobian was basically the best product in the automotive market at that time, but the processor of arm Cortex A57 in the consumer market was not unusual.

How risky is it to use electronic components that are not in the car

This problem is really complicated, and it has to be judged from many aspects:

1. It is just that it has not obtained the relevant certification, but in fact, the performance and reliability of the product meet the requirements, and it has also been verified by a large number of applications. If this is the case, the risk is relatively small.

2. This is an important point, that is, the relationship between the component and the system. The performance and reliability of the system is composed of the next level of electronic components, so under the same design, the use of non-car component products is definitely worse. However, a good design can reduce the performance requirements of the component, a protective measure is well designed and can achieve a slight impact on the system of component failure, it is possible to use non-vehicle components to make a better product.

Due to the impact of current technical process limitations, not every electronic component that needs to be used in the car can meet the so-called vehicle specification requirements. However, in order to achieve some functions on the car, these components must be used. This situation can be divided into two categories:

a. The safety requirements of this function are high and deviations are not acceptable

Example: E-CALL function for emergency calls, in order to ensure this function, the device needs to be equipped with a backup battery. This feature is life-safe and requires a Grade B rating according to the ASILI (ISO26262) rating of some companies.

And we know that it's difficult for batteries to maintain high performance at -40 degrees. Therefore, the company's solution is to heat the resistance wire on the battery, heat it at low temperature to ensure performance, at this time with a single component of the standard to see the unqualified, but as a part assembly, you can meet the standard requirements of the car factory. This can also be seen in the relationship between the corporate standards of OEMs and component standards.

b. This function generally does not involve safety and can be considered to accept deviations

Such as the LCD screen of the entertainment system. Both the response and optical performance that may be displayed at low temperatures will be degraded. But this situation will be accepted by some engineering personnel.

3. Some "bold" people who are not careful, out of certain ideas, such as reducing costs, or can get better performance, and only want to verify their performance and reliability in a short period of time through a small number of samples, in this case I can only say that the future things depend on character, no one knows what will happen.

Source: BC-AUTO, AutoIO and other network content synthesis