"On average, there are 8 new energy vehicles that have fires (including spontaneous combustion) every day. "This is the latest data released by the statistics of the emergency management department. At the 2022 World Power Battery Conference, Sun Jinhua said that the probability of China's electric vehicles catching fire in 2021 has rapidly climbed to 0More than 03%, has exceeded the traditional fuel vehicle 001~0.02%。
It can be said that with the deepening of the electric vehicle market, more and more automakers and consumers are paying more attention to the issue of safety and reliability.
When a circuit is short-circuited, the current can reach tens of thousands of amperes, and the instantaneous arc can vaporize the metal it touches into ions in a matter of milliseconds. Conversely, electronic circuits fail all the time, either due to external influences or due to degraded component performance over time. This is where the performance of the fuse comes into play.
With the rise of new energy vehicles and the rapid development of intelligent vehicles, there are more and more scenarios in automotive electronic equipment that require fuses to provide overcurrent protection.
Littelfuse has been one of the first companies on the market to offer AEC-Q200 certified fuses, and the company has contributed to the development of this standard and the testing requirements for fuse fuses.
How AEC-Q200 Escorts Car Safety
Littelfuse is both the drafter and the leader of the AEC-Q200, and it is Littelfuse's duty to promote the AEC-Q200 in the Chinese market. Yaosheng Du, senior application technology engineer at Littelfuse, said.
In fact, similar to chips, fuses are no exception to the development of automotive-grade components that define safety requirements for components used in automobiles.
Why should I use a fuse in a car?The most critical point is safety, and the fuse is a "safety device". For many car manufacturers, in the pursuit of domain control performance, 100 kilometers of acceleration, is always safety, but also the focus of consumer attention. At present, many manufacturers and engineers are beginning to realize its importance and gradually pursue safer and more reliable vehicle performance.
The fuse defines a weak connection, and when there is a fault and a breakpoint, it can be disconnected at the first time to avoid a short circuit of the battery and equipment from ignition. Of course, a weak connection does not mean that it is unreliable, "when it should be broken, when it should not be broken", safety and reliability are not separated, the seemingly simple problem, there is actually a lot of content involved behind it, and the requirements for the fuse are also very harsh, AEC-Q200 is around these two points to start.
The Automotive Electronics Council (AEC) was established in 1994 by Chrysler, Ford, and General Motors to standardize the reliability and certification standards of automotive electronic components.
AEC-Q is the International Association of Automotive Electronics Association's automotive verification standards, including AEC-Q100 (integrated circuit IC), AEC-Q101 (discrete semiconductor), AEC-Q102 (discrete optoelectronic semiconductor), AEC-Q103 (sensor), AEC-Q104 (multi-chip module), AEC-Q200 (passive components).
Although the AEC-Q reliability standard is not mandatory in China, if you want to enter the automotive field, it is essential to pass this certification, and it has also become the consensus of the industry. This means that once the component product has passed the above tests and is marked with the AEC-Q logo in the datasheet, it also means that the material has passed the vehicle specification certification and can be safely applied on the car.
AEC-Q200 is a specification for the reliability testing and certification of passive components, which has undergone several iterations since June 2010, including resistance, capacitance, inductor, transformer, resonator, crystal, PTC, NTC, varistor, etc., and the two main tests are environmental stress and physical property stress.
Since Rev D, there has been no change for more than a decade, and the AEC-Q200 specification does not cover fuses (fuses).
On March 20, 2023, starting with Rev E, the fuse was expanded into its product category, and Littelfuse contributed to the refinement of this version and the definition of the framework. This means that the automotive fuse has its own specification, and there is also a basic specification for reliability testing, which is a milestone moment for electric vehicle (EV) fuses.
Compared with non-automotive products, AEC-Q200 test products have more stringent conditions in electrical testing, temperature cycling, humidity testing, service life, high-frequency vibration, and high-temperature storage.
For example, the minimum temperature is 55 and the maximum temperature is 120 150, which meets the harsh ambient temperature of the car1000 times of temperature cycle test and 1000 hours of humidity test to meet the safety of the car in the high temperature and high humidity environmentThe service life of 1000 hours at the highest specific operating temperature can better meet the needs of automobiles for product durability. From the perspective of AECQ test standards, it is more stringent than any traditional standard in the past, and with the preparation of PPAP documents, all automotive fuse safety specifications have become designed to rely on.
A good engineer will optimize the design of the reduction margin of the fuse to ensure the safety and reliability of the circuit, all the best design is the result of local and overall compromise, not uneven, margin design is a technology and an art", according to Du Yaosheng's introduction, it is precisely because of the strict requirements of AEC-Q200 that it can better serve the reduction margin and ensure the final safety of the vehicle.
The demand for safety and reliability is increasing
The story of Littelfuse's products and automobiles goes back more than 90 years.
As early as 1930, Littelfuse's first small fuse was used in automobiles. In 1950, Littelfuse developed circuit protectors. In 1976, Littelfuse developed the world's first blade fuse, which is similar to the blade battery, with a distributed, independent safety design. Since then, Littelfuse has been used in automobiles.
To this day, Littelfuse products have been manufactured in accordance with international requirements, and we have been designing products in close contact with manufacturers to continue to develop forward-looking products.
Not long after the release of AEC-Q200E, Littelfuse also quickly launched automotive fuse products that meet the new AEC-Q200 certification, including high-voltage SMD, low-voltage SMD, high-voltage low-current SMD, high-current SMD fuse, etc., covering various voltage and current levels, becoming one of the first manufacturers of AEC-Q200 certified fuses.
As a member of the AEC Technical Committee, Littelfuse not only contributes to the development of the revised E, but also achieves ISO 9001, ISO 14001 and IATF 16949 for its global manufacturing sites, as well as internal testing in accordance with the new AEC-Q200 requirements.
Of course, to meet market demand, Littelfuse also offers a wide selection of AEC-Q100, AEC-Q101, and AEC-Q200 compliant devices.
In automobiles, we have observed that the pursuit of safety and reliability continues to increase, whether it is infotainment and communication, networking systems and body electronics, advanced driver assistance systems, or powertrain, chassis and safety systems. Du Yaosheng said that Littelfuse not only realized the concept conversion from small fuses to high-voltage fuses, but also gradually carried out a development of uses, including 12V power distribution, compressors, ECU traction converters, DC DC converters, heat pumps, PTC heating, high-voltage battery wiring sets and other automotive applications, and the shadow of Littelfuse can be seen in every circuit function module, and "Littelfuse everywhere" in the protection of electric vehicles.
For example, the 828 series achieves 1000V, the working temperature is -55 125, and the breaking capacity is 10Ka;The 526 series achieves 500V AC and DC;The 527 series achieves 500V AC and is particularly suitable for OBC input and DC DC conversion.
For another example, 441A, 501A, 407A, 438A, 440A, 483A, 437A, 422A surface-mount thin-film chip fuses are all in line with AEC-Q200 standards, with a wide range of products and a wide range of current levels.
With the release of AEC-Q200E, future automotive fuses also have their own specifications and standards. For Littelfuse, the AEC-Q200 is actually just the bare minimum for its product entry. "In fact, different models on the market have different requirements for fuses, and Littelfuse will meet higher requirements according to different models. Du Yaosheng said.