Fuji Electric Review
Vol.61-No.4,2015

Power Semiconductors Contributing in Energy Management

Power Semiconductors Contributing in Energy Management

[Purpose]

High-efficiency energy usage has become an extremely important factor in achieving a low-carbon society. In particular, electric energy has become indispensable in numerous fields such as automobile, industrial machinery, social infrastructure and consumer electronics, and as such, there is much expectation that advances in power electronics technology will enable the high-efficiency usage of electric energy. Fuji Electric has been developing easy-to-use power semiconductors that are characterized by their high energy conversion efficiency and low noise as key devices in the field of power electronics technology.
In this special issue, we will introduce the latest technologies and products of Fuji Electric's power semiconductors.

All-SiC Module Packaging Technology

NAKAMURA, Hideyo; NISHIZAWA, Tatsuo; NASHIDA, Norihiro

We applied the All-SiC (silicon carbide) module with new package structure to mega solar power conditioning sub-system (PCS), achieving 98.8% energy conversion efficiency and resulting in energy conservation. Key technologies are 3-dimensional wiring using Cu pins with power board instead of conventional Al wiring and full-mold structure using the thermosetting epoxy resin. These technologies lead to small package size, low inductance, and high reliability. We have optimized the package design to bring out the intrinsic performances of SiC device. Resin flow analysis and its visualization methods are carried out to design molding process, resulting in the full mold structure with free air void.

1,700-V Withstand Voltage SiC Hybrid Module

ONEZAWA, Takumi; KITAMURA, Shoji; ISO, Akira

Fuji Electric has developed a SiC hybrid module with a 1,700-V withstand voltage. It is designed for use in the traction market as a power device that can be utilized in inverters that contribute to energy savings. This module is equipped with 6th-generation IGBT chips and applies SiC-SBD chips to its FWDs. It has a product rating of 1,700 V/1,200 A (2 in 1) and has 2 specifications: standard specifications that make much of power dissipation, and low VCE(sat) specifications suitable for low switching frequencies. The standard specifications reduce loss by 18% compared with conventional Si modules. Furthermore, the low VCE(sat) specifications achieve 6% loss reduction compared with the standard specifications at low switching frequency condition.

3,300-V Withstand Voltage SiC Hybrid Module Technology

KANEKO, Satoshi; KANAI, Naoyuki; TSUJI, Takashi

There has been increasing demand for electronics to achieve not only energy savings, but also be more compact, lightweight and improved performance such as high output. Fuji Electric is seeking to meet these demands by pursuing the development of a SiC hybrid module with a 3,300-V withstand voltage. By adopting the SiC-SBDs that we developed in partnership with the joint research body Tsukuba Power-Electronics Constellation (TPEC), we have been able to reduce generated loss by 24% compared with current Si modules. In addition, we have also utilized Sn-Sb solder to ensure high reliability and have been able to improve continuous operation temperature by 25 °C. Moreover, we made use of the reducing effect of generated loss to achieve improvements in power density while also reducing the footprint size by approximately 30%.

7th-Generation “X Series” IGBT Module

KAWABATA, Junya; MOMOSE, Fumihiko; ONOZAWA, Yuichi

In recent years, the IGBT module market has been seeing increasing demand for compact modules with low loss and high reliability. In order to meet these demands, we have developed the 7th-Generation “X Series” IGBT Module. By significantly reducing the loss of IGBT and FWD chips and developing a package characterized by its high heat dissipation, high heat resistance and high reliability, we have reduced the module’s footprint by approximately 36% and power loss by approximately 10% and achieved long-term reliability. Furthermore, by enhancing its withstanding and characteristics during high-temperature operation, we increased the maximum temperature for continuous operation to 175 °C, from the conventional temperature of 150 °C. These enhancements have enabled the module to significantly increase output current, and this further increase the power density and miniaturizes the size of power converters.

2nd-Generation Small IPM

ARAKI, Ryu; SHIRAKAWA, Toru; KOGAWA, Hiroki

Fuji Electric has been developing small intelligent power modules (IPMs) that integrate into a single package the power devices and control IC needed in the system construction of motor drives. We have now developed a 2nd-generation small IPM based on 7th-generation IGBT technology to achieve even more energy savings. The module reduces the loss by 10% or more in the intermediate load region, such as in the case of a 5.6-kW air conditioner, and by 20% or more in the rated and maximum load region compared with the 1st-generation module. In addition, temperature rise in the soldering on the circuit board has also been reduced by approximately 20 °C compared with the 1st-generation module. Overall, the module achieves enhanced energy savings, expands output current, and increase reliability during circuit board mounting and a greater degree of freedom during system design.

HVIC Technologies for IPM

JONISHI, Akihiro; AKAHANE, Masashi; YAMAJI, Masaharu

A high voltage integrated circuit (HVIC), which is a gate driver IC with a high breakdown voltage, is one of the key devices required in enhancing the functionality of intelligent power modules (IPMs). Fuji Electric has developed HVIC technology characterized by its advanced functionality, compactness, high reliability, and guaranteed industrial use at 600 V/1,200 V for small- and medium-capacity IPM. By reducing the circuit area and adopting high breakdown voltage technology and enhanced noise resistant level-shift circuit technology, we have reduced the chip size by 20% while improving the breakdown voltage and reliability. In addition, we have achieved over-current and overheat protection circuit technology for upper-arm IGBT, as well as level-down functionality for alarm signals.

3rd-Generation Direct Liquid Cooling Power Module for Automotive Applications

ARAI, Hirohisa; HIGUCHI, Keiichi; KOYAMA, Takahiro

Fuji Electric has developed a 3rd-generation direct liquid cooling power module for hybrid and electric vehicles. The power module has a rated capacity of 750 V/800 A, which is designed for motor capacity of 100 kW. The market for automotive application based power modules has been requiring increased efficiency and module miniaturization. To meet these demands, we have improved exothermicity by adopting a water jacket for integrating the cooling fins and cover while also increasing the reliability of the solder, thus enabling the module to achieve continuous operation at 175 °C. Furthermore, we have miniaturized the power module by adopting an RC-IGBT that integrates IGBT and FWD.

Packaging Technology of 3rd-Generation Power Module for Automotive Applications

GOHARA, Hiromichi; TAMAI, Yuta; YAMADA, Takafumi

The development and popularization of hybrid and electric vehicles has been accelerating in recent years. These new vehicles demand miniaturized, light-weight and higher-output power module in order to improve fuel efficiency. Fuji Electric has developed high heat dissipating cooling unit for direct water-cooled structures, an ultrasonic bonding technology for electrodes and copper terminal, and new long-life solder that applies both precipitation strengthening and solid-solution strengthening. By applying these technologies, the 3rd-generation power modules for automotive applications that utilize RC-IGBT dies achieve greater reliability, about 30% smaller footprint and thinner structure compared to the previous generation.

RC-IGBT for Automotive Applications

YOSHIDA, Soichi; NOGUCHI, Seiji; MUKAI, Koji

The number of hybrid electric vehicles and electric vehicles in use on the road has been increasing as a measure to reduce CO2 emissions in order to protect the environment from phenomena such as global warming. In order to improve fuel efficiency for these types of vehicles, they need to reduce loss in mounted semiconductor devices, while also decreasing the size of the inverter. To meet these needs, Fuji Electric has been working to develop an RC-IGBT that integrates an IGBT and FWD into one chip. Moreover, we have optimized trench gate spacing, a field stop layer and lifetime control for the RC-IGBT for automotive applications. As a result, the inverter achieves an about 20% reduction in generated loss during the operation compared to using conventional RC-IGBTs for automotive applications.

Relative Pressure Sensor for Automobile Fuel Tanks

KATO, Hirofumi; ASHINO, Kimihiro; SATO, Eisuke

In recent years, there has been increasing regulation to reduce the environmental burden of automobiles. One example of such regulation is the requirement to detect fuel leaks in the United States. Fuji Electric has developed a relative pressure sensor for automobile fuel tanks capable of being directly mounted to a pipe inside the engine room. The sensor is used for controlling vaporized fuel exhaust suppression devices that recover vaporized fuel to incinerate it in the cylinder. Based on our 6th-generation compact pressure sensor technology, we have successfully improved resistance to vaporized fuel, enhanced protective functions and reinforced EMC to both ensure durability and achieve high-precision detection.

PWM Power Supply Control IC “FA8B00 Series” Capable of Handling Peak Loads

MATSUMOTO, Shinji; YAMANE, Hiroki; YABUZAKI, Jun

In recent years, the notebook computer and inkjet printer market requires increasing the maximum output power for new CPUs and motor drive loads. To meet these requirements, Fuji Electric has developed the “FA8B00 Series” of pulse width modulation (PWM) power supply control IC capable of handling Peak loads. This IC can increase the switching frequency up to 130 kHz in accordance with rise in FB terminal voltage, allowing it to increase the maximum output power of a power supply without increasing the volume of a transformer. Furthermore, the IC comes equipped with an expansion function for switching frequency jitter that enables it to achieve low EMI noise characteristics even against varying loads.

2nd-Generation Low-Loss SJ-MOSFET “Super J MOS S2 Series”

WATANABE, Sota; SAKATA, Toshiaki; YAMASHITA, Chiho

In order to use energy efficiently, there has been increasing demand for enhanced efficiency in power conversion equipment, and power metal-oxide-semiconductor field-effect transistors (MOSFETs) that are equipped with it have been required to be compact, low loss and low noise. Fuji Electric has developed the easy-to-use 2nd-generation low-loss SJ-MOSFET “Super J MOS S2 Series” that reduces on-resistance Ron・A, which is standardized by unit area, and improves the trade-off characteristic between turn-off switching loss Eoff and the VDS surge at turn-off switching. The adoption of this product is expected to improve the efficiency of power conversion equipment.

High-Speed Discrete IGBT “High-Speed W-Series”

HARA, Yukihito; NAITO, Tatsuya; KATO, Yoshiharu

Since power conversion efficiency is an important factor for uninterruptible power systems (UPSs) and power conditioning sub-systems (PCSs) for photovoltaic power generation, switching devices used in the equipment are required to reduce the power loss. For compact inverter welding machines, utilized devices are required to have lowloss characteristics and high-speed switching to make conveyance easier. The high-speed discrete insulated-gate bipolar transistor (IGBT) that we have developed and released reduces parasitic capacitance in active parts and optimizes the field stop layer, thereby achieving a 10% reduction in loss for 650-V products and a 19% reduction in loss for 1,200-V products when compared to the conventional product.