In today's rapidly developing energy storage technology, stronger power generation and storage capabilities, higher energy management efficiency, and more stable transmission capabilities are all directions pursued by related enterprises. This requires more powerful IGBTs to meet the high demands of current energy storage technology. The emergence of the seventh-generation IGBT perfectly fits the development needs of energy storage.

The 7th Generation IGBT is Accelerating Development

The development of IGBT can be traced back to the 1980s, with the initial IGBT adopting the planar punch-through (PT) structure. This type of IGBT started with a heavily doped P+ substrate, but it had issues such as a negative temperature coefficient and poor consistency in on-state voltage drop, which was not conducive to parallel use. Nevertheless, it initiated the application of IGBT in the field of power electronics.

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Over time, IGBT has undergone multiple iterations, transitioning from a non-punch-through (NPT) structure to a field-stop (FS) structure, and the gate structure also evolved from planar to trench type (Trench). These improvements gradually enhanced the performance of IGBTs, including reducing conduction voltage drop, shortening switching time, and increasing off-state voltage, which are the changes from the second to the fifth generation of IGBTs.

By the sixth generation, IGBT further optimized the trench structure and field-stop technology, significantly improving current density and energy efficiency, reducing switching losses, and showing a notable improvement in high-temperature operation.

Around 2018, the seventh-generation IGBT, which began to be introduced to the market, incorporated micro-trench gate + field-stop (Micro Pattern Trench) technology, marking a significant leap in IGBT technology. The characteristics of the seventh-generation IGBT include higher channel density, optimized cell design, lower parasitic capacitance, and the ability to maintain optimal performance even at extreme switching speeds (such as 5kV/μs). This enables IGBT7 to reach new heights in reducing static losses, increasing switching speed, and enhancing high-temperature operation capabilities, making it particularly suitable for high-performance applications such as electric vehicles, renewable energy systems, and high-voltage direct current transmission.

The micro-trench technology improves carrier transport characteristics, thereby reducing static losses without sacrificing switching speed. This means that under the same operating conditions, the seventh-generation IGBT can more efficiently convert electrical energy and reduce heat generation. Moreover, compared to the sixth-generation IGBT, the static losses of the seventh generation are reduced by about 30%, which is crucial for improving system energy efficiency and reducing cooling requirements.

Additionally, data shows that with the same packaging volume, the current output capability of the seventh-generation IGBT has increased by more than 50%, thanks to the higher current density, making device miniaturization possible, or increasing the system's power output without changing the volume.

Furthermore, the seventh-generation IGBT also meets the electronic industry's demands for higher efficiency, smaller size, higher power density, and lower losses. The seventh-generation IGBT technology significantly improves the cost-performance ratio of IGBTs by achieving a 20% reduction in area, a chip thickness reduction from 120 micrometers to 80 micrometers, and a conduction voltage drop from 1.7V to 1.4V.

For example, using the seventh-generation IGBT in energy storage systems allows for the design of systems with stronger power generation and storage capabilities, improving energy management efficiency and enhancing storage capacity, thereby more smoothly integrating solar power into the grid. In addition, modules designed with the seventh-generation IGBT also support the storage of excess power in energy storage systems, effectively alleviating the intermittency issues of solar power generation and ensuring the reliability and stability of power supply.Seventh-Generation IGBT Empowers the Energy Storage Industry

Due to the outstanding performance of the seventh-generation IGBT, an increasing number of companies are utilizing this product in the field of energy storage. For instance, recently, ShangNeng Electric adopted Infineon's IGBT7 EconoDUAL®3 to achieve a 2MW energy storage inverter PCS in a single machine. This uses Infineon's latest EconoDUAL 3 packaging with a 750A 1200V module, model number FF750R12ME7_B11.

The EH-2000-HA-UD employs the FF750R12ME7, which is a 1200V/750A IGBT module. The chip is based on Infineon's latest IGBT7 technology. Unlike Infineon's previous IGBT4 technology, IGBT7 features a more refined MPT (Micro Patterned Trench) technology, with higher channel density, thinner chip thickness, and a meticulously designed cell structure and spacing. It also optimizes parasitic capacitance parameters, thereby achieving optimal switching performance.

Moreover, recently, ON Semiconductor has also released the seventh-generation 1200V QDual3 IGBT power module. Compared to other similar products, this module has a higher power density and provides an additional 10% output power.

According to ON Semiconductor, the 800A QDual3 module is based on the new field-stop seventh-generation (FS7) IGBT technology. When applied in a 150KW inverter, the QDual3 module's loss is 200W less than the closest competitor, thus reducing the size of the heat sink. It is suitable for central inverters in solar power stations, energy storage systems, commercial agricultural vehicles, and industrial motor drivers, among other high-power converters.

Many domestic companies have also successively launched seventh-generation IGBTs. For example, Star Semiconductor introduced a new generation of automotive-grade IGBT chips based on the seventh-generation micro-trench technology in 2022. The product models include 650V/750V/1200V IGBT chips, which use the seventh-generation micro-trench Trench Field Stop technology. This technology can reduce the area by 20%, the chip thickness from 120 microns to 80 microns, and the conduction voltage drop from 1.7V to 1.4V.

Additionally, by the end of 2023, BYK also developed a full series of seventh-generation IGBT chips and successfully achieved mass production, breaking through the technological barriers in the field of domestic production. This seventh-generation IGBT product significantly outperforms similar IGBT chips using traditional processes in terms of performance, effectively solving the difficult balance between conduction loss and switching loss. It has the dual advantages of low conduction loss and low switching loss, and its applicable frequency range has also been broadened, with the highest applicable frequency increased from 15kHz-20kHz to 30kHz-40kHz.

Currently, this product has passed strict testing and certification by several industry-leading companies and has been supplied on a small scale in fields such as electric vehicles, wind power generation, photovoltaic inverters, and high-end chemical energy storage.

WeiRui Shares has recently obtained a new utility model patent authorization, named "A New Trench IGBT Structure." This patent provides a new trench IGBT structure that reduces the gate contact hole, transforming the polycrystalline silicon in the corresponding gate trench into polycrystalline silicon of the first emitter trench, thereby reducing the gate capacitance, increasing the device turn-on speed, and reducing turn-on loss. The new trench is a significant feature of the seventh-generation IGBT.

Furthermore, companies such as XingJieNeng, ZhenHua Technology, and AnJian Technology have also made achievements in the seventh-generation IGBT, providing advanced power semiconductor solutions for new energy vehicles, photovoltaic energy storage, and industrial control fields in China and globally.Summary

Internationally, companies from Europe, America, and Japan such as ON Semiconductor have taken the lead in the development and commercialization of seventh-generation IGBT technology, thanks to their profound technical expertise and financial strength. Chinese IGBT companies, including StarPower Semiconductor and Xingjie Energy, are also accelerating their pursuit, successfully developing and launching seventh-generation IGBT products, which signifies a significant breakthrough for domestic companies in the core technology of IGBT. Particularly, the rapid development of the energy storage industry has provided a vast application market for the seventh-generation IGBT, and in turn, the seventh-generation IGBT has also accelerated the growth of the energy storage market.