Fuji Electric Review
Vol.66-No.4,2020
Power Semiconductors Contributing to Energy Management
Power Semiconductors Contributing to Energy Management
Fuji Electric is committed to helping achieve a sustainable society through its energy and environment businesses. This goal is one of the core pillars of our management policies and is reflected in the promotion of SDGs in all corporate activities, including those involving the supply chain. This enables us to contribute to solving social and environmental issues such as global warming. These initiatives are allowing us to respond to the international community’s goal of realizing an integrated economic, social and environmental framework in order to achieve a responsible and sustainable society.
In order to realize a low-carbon society, it is very important to improve the performance of the power semiconductor devices that are pivotal to operate power electronics equipment used in various industrial and social infrastructure systems. In this special issue, we will introduce the latest technologies and products related to Fuji Electric’s power semiconductor devices.
OGASAWARA, Satoshi
ONISHI, Yasuhiko; MIYASAKA, Tadashi; IKAWA, Osamu
The international community is working to achieve a sustainable society through energy and environmental initiatives. To facilitate this, Fuji Electric has been promoting SDGs in all corporate activities, including those involving the supply chain. This has enabled us to contribute to solving social and environmental issues such as global warming. In this regard, power electronics are driving measures to solve environmental problems through increased energy savings and decarbonization. The power semiconductors introduced in this special issue are being used as key devices in power electronics and are contributing to the realization of a responsible and sustainable society through technological innovation.
In this paper, we describe the current status and future outlook of power semiconductor products and technologies.
HARA, Yasufumi; YOSHIDA, Soichi; INOUE, Daisuke
In recent years, measures to achieve energy savings and reduce CO2 emissions have accelerated the switchover to xEVs, such as hybrid vehicles and electric vehicles, throughout the world. The IGBTs used in the inverters of xEVs are being required to enhance their capability to withstand over current (I2t capability) at the time of accident.
Fuji Electric has developed IGBT modules for xEVs that use RC-IGBTs and a lead frame to connect to the circuit of RC-IGBT surface electrodes, improving I2t capability. The I2t capability is 2.6 times higher for the new structure combining RC-IGBTs with a lead frame than for the conventional method using discrete FWDs and wire bonding.
TAMAI, Yuta; KOYAMA, Takahiro; INOUE, Daisuke
In the automobile industry, the switchover to electricity-powered electric vehicles (EVs) and hybrid electric vehicles (HEVs) has been accelerating. This has increased the demand for smaller, thinner, and more reliable power modules for xEVs. To meet this demand, Fuji Electric has been developing direct water cooling structures that integrate a heat sink and water jacket. The cooling performance of the structures has improved with each successive generation. Compared with conventional open fin structures, the direct water cooling structure can suppress cooling unit deformation. This characteristics allows the heat sink base to be thinned up to 20% to achieve better heat dissipation performance and increase the temperature cycling capability more than twice, improving overall reliability.
IWATA, Hideki; TOYODA, Yoshiaki; NAKAMURA, Kenpei
As automobiles have been electrified, their electronic control system is becoming large scale. This has increased the demand for miniaturization and high heat dissipation in system components. It is against this backdrop that Fuji Electric developed the “F5202H” 5th-generation intelligent power switch (IPS) for automotive applications. The F5202H comes with an operational amplifier that detects load currents with high accuracy, and utilizes a device with a triple-diffused structure. As a result, it has reduced a chip size by 45%, while maintaining the same basic functions. Furthermore, it uses a small outline non-leaded (SON) package to contribute to miniaturization and high heat dissipation, reducing the package size by 45% and thermal resistance by 80%. The F5202H is designed to be used in the harsh environments of engine compartments and complies with the AEC-Q100 reliability standard for automotive electronic components.
KAKEFU, Mitsuhiro; YAMANO, Akio; HIRATA, Tomoya
In order to meet the market demand for smaller and more reliable IGBT modules, Fuji Electric has developed reverse-conducting IGBTs (RC-IGBTs), which integrate IGBTs and FWDs on a single chip. Specifically, we created a line-up of 7th-generation “X Series” 1,200-V RC-IGBT modules for industrial applications that combine 7th-generation “X Series” chip and packaging technologies with RC-IGBT technology. More recently, we have enhanced the line-up by adding 2,400-A products to increase the current rating. This enhancement substantially improves chip junction temperature and junction temperature rise during operation compared with conventional products. This contributes to further output improvement, miniaturization, and higher reliability for power conversion systems.
TAKASAKI, Aiko; OKUMURA, Keiji; MARUYAMA, Rikihiro
Fuji Electric has been commercializing Si-IGBT modules for use in a variety of power conversion systems in order to contribute to the realization of a low-carbon society. We have developed All-SiC modules equipped with 2ndgeneration trench gate SiC-MOSFET chips to improve the power conversion efficiency. While maintaining compatibility with conventional products, internal inductance and power loss has been reduced by taking advantage of the low on-resistance of the 2nd-generation SiC trench gate MOSFET. As a result, the inverter generation loss can be reduced by 63% compared to the conventional Si-IGBT module, which contributes to higher density and miniaturization of power electronics equipment.
TERASHIMA, Kenshi; OYOBIKI, Tatsuya; OSE, Tomofumi
Fuji Electric has developed a new IGBT-IPM to meet the requirements of the further miniaturization, high efficiency, and high power of conversion systems by using the “P644” package, which is the industry’s smallest class for IPMs equipped with a brake circuit. This IPM is included in our line-up of the “X Series” IPMs, which uses a 7thgeneration chip and packaging technologies. The new X Series IPM has lower power dissipation than the conventional “V Series” IPMs using “P636” by approximately 17% and can operate in high-temperatures up to 150 °C. These enhancements can reduce the module footprint by approximately 12% and increase inverter output current by approximately 26%.
HARA, Yukihito; MAETA, Ryo; SAKAI, Takuma
To further improve the effi ciency of electric systems, reducing power loss is pivotal to the semiconductor switching devices used in uninterruptible power systems (UPSs) and power conditioning systems (PCSs). Fuji Electric has thus been mass producing 650-V and 1,200-V “XS Series” discrete IGBTs, which improve conduction loss and switching loss trade-off characteristics to enhance the effi ciency of UPSs and PCSs. We have developed and added a module to the product line-up that uses a TO-247-4 package, which has a sub-emitter terminal capable of further reducing switching loss. The new module has a rated capacity of 1,200 V/75 A and lower switching loss than the conventional TO-247 package products by 20% to 30%.
HIASA, Nobuyuki; ENDO, Yuta; YAGUCHI, Yukihiro
As electronic devices become smaller and lighter, switching power supplies are becoming more widely used and are required to help electronic devices, such as LED lighting, to have a long life, low price, and high reliability while reducing power supply costs. To meet these demands, Fuji Electric developed the “FA1B00N” 4th-generation critical conduction mode (CRM) power factor correction (PFC) control IC. In addition to the conventional model’s functions, this IC features a startup overshoot reduction and other protective functions, as well as higher accurate detection for PFC output voltage and overvoltage. These enhancements enable it to improve the reliability of electronic devices and reduce power supply costs.
TAWARA, Takeshi; BABA, Masakazu; TAKENAKA, Kensuke
Fuji Electric formed a 4H-SiC-based 1.2-kV SiC Superjunction MOSFETs (SiC-SJ-MOSFETs) by repeating ntype epitaxial growth and Al ion implantation and verifi ed its static and reverse recovery characteristics. The on-resistance of the SiC-SJ-MOSFETs at 175 °C was 55% to 65% that of the conventional trench gate MOSFETs. In terms of reverse recovery characteristics, the SiC-SJ-MOSFETs did not show an excessive surge voltage despite a slight increase in reverse recovery charge at 175 °C compared with conventional SiC trench gate MOSFETs. We expect that the use of SiC-SJ-MOSFETs in inverter circuits will contribute to reducing total loss.
Upper arm and lower arm
In switching circuits used in inverters and other electrical equipment, a circuit that supplies current from the power supply to the electrical load is called upper arm. A circuit that draws current from the electrical load to power supply is called lower arm.
New Products
INUI, Daisuke; MATSUNAKA, Masayuki; NUNOMIYA, Tomoya
Fuji Electric has developed the “NSN4” neutron scintillation survey meter that can measure the 1-cm ambient dose equivalent rate at nuclear facilities, accelerator facilities and advanced medical facilities. 3He is currently the most widely used material for neutron detectors. Its supply is limited because it is almost non-existent in nature and is produced artificially. Furthermore, its supply is susceptible to international circumstances. In particular, the demand for 3He has increased worldwide because it has been being used to test suspicious substances, such as radioactive materials, in counter-terrorism activities. This has increased its price and made it even more difficult to procure. It is against this backdrop that Fuji Electric has commercialized a neutron scintillation survey meter that does not use 3He. To achieve this, the detector uses a scintillator, which emits light when radiation is incident. Figure 1 shows the external appearance of the meter.
KOBAYASHI, Nobuyuki
Fuji Electric has been supplying electrical equipment for Shinkansen train throughout the entire history of the Tokaido Shinkansen, starting with the Series 0 up to the N700A. Central Japan Railway Company has developed the N700S, the first fullyredesigned in 13 years since the release of the N700 Series. The N700S is aimed at safer and more stable transportation and designed to improved environmental performance, such as energy savings, comfort, and convenience for passengers. The N700S is a standard train that is able to flexibly accommodate various train consists other than 16 car-sets, such as 8-car sets and 6-car-sets.
To complete the next-generation N700S trains, Fuji Electric has developed the traction equipment and the fully active damper drive system to be incorporated into the fully active damping control system. We completed the functionality and performance evaluation of the electrical equipment using prototype train and delivered it for use in the mass-produced N700S trains (see Fig. 1).
HASHIZUME, Yuichi; UCHIDA, Takafumi; OSE, Naoyuki
In order to deal with environmental problems such as global warming and to achieve a low-carbon society, energy conservation through high-efficiency power electronics equipment and the use of renewable energy are being promoted. Under such circumstances, the market for power semiconductors used in power electronics equipment is expanding in a variety of fields, including automobiles, railways, energy systems, and industrial equipment. Conventional power semiconductor devices using silicon (Si) are approaching theoretical property limits due to material properties. For this reason, silicon carbide (SiC), which has a band gap approximately three times larger and a breakdown field strength approximately ten times greater than Si, is expected to be the material used for power semiconductors that surpass the property limitations of those that use Si in order to further reduce the size and increase the efficiency of power electronics devices(1). Fuji Electric has mass-produced SiC-based Schottky barrier diodes (SBDs), planar gate metal-oxidesemiconductor field-effect transistors (MOSFETs), and trench gate MOSFETs, which are used in power conditioning systems (PCSs) for solar power generation, industrial inverters, and inverters used in railcars(2)-(11).
Figures 1(a) and 1(b) show the hybrid SiC module product with Si-IGBT and SiC-SBD developed by Fuji Electric, and Fig. 1(c) shows the SiC-SBD discrete product.
This article describes a 2nd-generation SiC-SBD with improved characteristics and forward surge withstand capability compared with the 1st-generation SiCSBD. This product series is available in the rated voltages of 650 V and 1,200 V, and the product with the rated voltage of 650 V is discussed in this article.