FUJI ELECTRIC JOURNAL September/2004 (Vol.77-No.5)
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1. Semiconductors
2. Radiation Monitoring Systems
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Fuji Electric's Semiconductors: Current Status and Future Outlook
Hirokazu Kaneda, Akinori Matsuda
In the field of power electronics, Fuji Electric offers specialized
semiconductor products for controlling electric power. These devices
include discreet semiconductor devices such as diodes and MOSFETs,
as well as IGBT modules and power ICs. Fuji Electric is focusing on
applications in the strategic markets of industrial, automotive and
information & power supply equipment. This paper presents an
overview of Fuji's main products, core technologies and future trends
of these markets.
U-series of IGBT Modules
Shuji Miyashita
Power conversion equipment, typified by general-purpose inverters
and uninterruptable power supplies, are subject to constant
requests for higher efficiency, smaller size, lower cost and quieter
operation. Power semiconductor devices used in the equipment are
required to have high performance, low cost and high reliability, and a
5th generation IGBT module (U-series), which provides a dramatic
performance improvement over the 4th generation IGBT module (Sseries),
has been developed. This paper introduces the product line of
U-series IGBT modules and describes the latest device technologies,
including NPT, trench-gate, field-stop and new FWD structures.
U-series of IGBT-IPMs (600V)
Kiyoshi Sekigawa, Hiroshi Endo, Hiroki Wakimoto
Fuji Electric has developed a 600V series of U-IPMs (20-160A).
A dramatic decrease in steady-state loss is achieved by using a trench
gate structure IGBT. Turn-on loss has also been reduced through the
use of a newly developed FWD chip that realizes soft recovery and
achieves higher
di/dt without an increase in noise. In practical applications,
the replacement of R-IPMs with the abovementioned U-IPMs
enables the carrier frequency to be increased by a factor of two.
Development of a Next-generation IGBT Module
Using a New Insulating Substrate
Yoshitaka Nishimura, Eiji Mochizuki, Yoshikazu Takahashi
Due to the recent demand for energy-efficient electronic products,
IGBT modules are being used not only in industrial applications but
also in home electronic appliances. Accordingly, in addition to the obvious
market demands for low cost and high reliability, IGBT modules
are also required to be lightweight and compact. In response to these
needs, an insulating substrate having low thermal resistance and high
strength was developed. This paper introduces the next-generation
IGBT module that utilizes this new insulating substrate and achieves
30% better thermal resistance than prior comparable structures.
Study of Gate Oxide Film Formation for Power
Semiconductor Devices
Ryosuke Matsumoto, Hirohisa Katoh
As silicon devices scale down, the application of ultra-thin oxide
films has recently been attracting attention. In power devices such as
MOSFETs and IGBTs, sometimes they are applied very thick gate
oxide films and high temperature annealing is sometimes required in
certain processes, various phenomena occur which are not observed in
the application of ultra-thin oxide films. This paper reports the results
of our investigation into the relationship between the electrical characteristics
of power devices and the gate oxide film formation conditions
such as oxidation method, film thickness and annealing method.
High Pressure Sensor Using One Chip Technology
Katsumichi Ueyanagi, Shigeru Shinoda, Kimihiro Ashino
In response to the expanding range of applications for high-pressure
sensors to automotive and industrial applications, Fuji Electric has
developed the world's smallest one-chip high-pressure sensor cell.
This paper presents an overview of the product, describes design considerations
for achieving the desired pressure resistance, and discusses
product performance and reliability considerations. The newly developed
high-pressure sensor cell is suitable for applications in the range
of 1 to 5MPa, and is ideally suited as a high-pressure sensor for air
conditioner and oil pressure control applications.
Low IR Schottky Barrier Diode Series
Mitsuhiro Kakefu, Masaki Ichinose
With the rapidly advancing trends toward the smaller size, lighter
weight and higher performance electronic devices, the environment in
which semiconductor devices are used is becoming more severe, especially
in devices such as AC adapters for which the trends toward
miniaturization and higher output are particularly noticeable. In
response, Fuji Electric has commercially produced a low
IR-SBD that is
ideally suited for use in the secondary source rectification of switching
power supplies in a high temperature environment. In order to optimize
the characteristics of chip specific resistance and thickness, guard
ring concentration, diffusion depth and barrier metal,
IR has been
reduced by approximately a factor of 10 compared to the conventional
SBD and the increase in VF has been suppressed to the maximum
extent possible so as to reduce power dissipation and to increase the
maximum operating temperature.
60V-class Synchronous Buck Regulator Control ICs
with Internal High Voltage MOSFET Switches
Masanari Fujii, Tamotsu Yoneda
In recent years, electronic devices have increasingly been made
with smaller size, lighter weight and higher performance. The power
supplies for driving these electronic devices are required to have a
small size, high output and high efficiency. To meet these needs, Fuji
Electric has developed and commercialized 3-channel or 2-channel output
type buck DC-DC converter ICs "FA7726F and FA7730F" that
contain an internal low on-resistance high-voltage power MOSFET on
their main side and on their synchronous regulator side respectively.
This paper introduces the characteristics of these control ICs and
describes example circuit applications.
Medium-voltage MOSFETs for PDP-use
Yukihito Hara, Masanori Inoue
Large-screen high-definitions plasma display panels (PDPs) are
rapidly growing in popularity. Targeting the sustain circuit, in which
there is tremendous need for low on-resistance, Fuji Electric has
newly developed a line-up of 150 to 300V SuperFAP-G devices. In
response to requests for even smaller sizes and higher efficiency, Fuji
has developed low on-resistance trench MOSFET technology. This
paper introduces Fuji Electric's line-up of MOSFETs for PDPs and presents
their characteristics.
PDP Scan Driver IC
Hideto Kobayashi, Gen Tada, Hitoshi Sumida
As flat panel displays (FPDs) increase in popularity, competition is
intensifying among the various types of FPDs (LCDs, PDPs and projectors).
For PDPs, performance improvements such as lower current
consumption and higher luminous efficiency, as well as lower cost are
needed. In response to these market needs, Fuji Electric has developed
and commercialized technology that enables a scan driver IC having
high current flow and low output on-resistance to be supplied at low
cost.
Device and Process Technologies for PDP Driver ICs
Hitoshi Sumida
This paper introduces Fuji Electric's device and process technologies
for plasma display panel (PDP) driver ICs. PDP driver ICs can be
categorized as either address driver ICs or scan driver ICs. Isolation
techniques, process technology and high-voltage lateral device technology
are described for each type of IC. Technical trends in the development
of both types of driver ICs at Fuji Electric are also discussed.
Current Trends in Radiation Monitoring System
Etsuo Kono
Radiation monitoring systems are installed to monitor radiation
and radioisotopes (RI) at nuclear power plants, hospitals and research
laboratories. Recently digital signal processing technology is adopted in
them in order to do more precise measurements of radiation. Silicon
semiconductor detectors, which can detect gamma, alpha and beta rays
and neutrons, are replacing the conventional radiation detectors in
radiation monitoring systems. A new radiation monitor suitable for
measuring neutrons is being developed for use in nuclear fuel processing
plants and accelerator facilities.
Personal Dose Monitoring System
Kei Aoyama, Osamu Ueda, Takeshi Kawamura
The integration of an electronic personal dosemeter in a personal
monitoring system is expected to enable the real-time evaluation of
measured values, achieve higher efficiency and realize other such
advantages. Fuji Electric has developed an electronic personal dosemeter
capable of measuring gamma rays (X-rays), beta rays and neutrons,
and has realized a monitoring system that integrates this electronic
personal dosemeter with a doorway-monitoring device. A radiation
source calibration device conforming to JIS has also been developed. In
the future, Fuji Electric intends to develop low cost, high precision and
easy-to-use products for use at a wide range of facilities.
Environmental Radiation Monitoring System
Toshihiro Takagi, Osamu Kimura, Atushi Minagoshi
At nuclear power plants, the dose rate of environmental gamma
radiations in the vicinity of the surrounding monitored areas and in the
neighboring towns must be measured and monitored continuously.
Environmental radiation monitoring system are critically important
systems that continuously measure the environmental gamma radiations
dose rates at specified measurement points and transmit that
measurement data in real-time to a central control room where
changes in the environmental radiation conditions are monitored centrally.
Moreover, the disclosure of this measurement data enables the
public to gain an understanding of the operation of the power plant.
This paper introduces Fuji Electric's latest environmental radiation
monitoring system.
Environmental Radiation Measuring Equipment
Hironobu Kobayashi, Tsuyoshi Sakamaki, Kaoru Masui
Nuclear power plants, research laboratories and medical facilities
use a wide variety of radiological instruments and devices for radiation
monitoring and control. Fuji Electric supplies a variety of radiological
instruments and devices for diverse uses. This paper introduces the
following two devices recently developed by Fuji Electric as environmental
radiation monitors.
(1) |
An environmental dosimeter for low-level radiation featuring a
nearly 100-fold increase in sensitivity compared with the
conventional detectable level |
(2) |
A transportable monitoring post equipped with a wider-range
NaI (Tl) scintillation probe |
Radioactive Contamination Monitor
Toru Hasegawa, Tadao Hashimoto, Manabu Hashimoto
At nuclear power plants, in order to prevent radioactive materials
from spreading contamination outside the radiation control area, the
surface contamination of all material transferred outside the control
area is monitored. This paper presents an overview and describes features
of: (1) personnel surface contamination monitoring assemblies for
measuring the surface contamination on workers, (2) articles surface
contamination monitoring assemblies for measuring the surface contamination
on articles of all sizes, (3) laundry monitors for measuring the
surface contamination on worker clothes worn inside the control area,
(4) whole-body counters for measuring the worker's internal exposure,
and (5) hand-foot-clothing contamination monitors for measuring the
surface contamination on hands, feet and clothing.
Large-scale Radiation Monitoring System
Toshiaki Fujimoto, Katsuhito Ito, Sadao Nakashima
Nuclear facilities monitor radiation in order to protect workers and
residents of neighboring communities from radiation exposure.
Radiation monitoring systems are extremely important systems that
continuously monitoring the radiation conditions within a facility and
the radioactivity concentration in gaseous and liquid waste emitted
from that facility. Fuji Electric has developed a sophisticated and highly
reliable large-scale radiation monitoring system in which radiation
detectors, provided with sophisticated and specific functionality for
measuring radiation, are distributed at various locations throughout
each site, data is transmitted via an Ethernet to a control room and a
UNIX server is used for data processing.
Radiation Control Computer System
Eiichi Mihoya, Kenichi Tanabe, Michio Akashi
Fuji Electric has adopted for the first time a browser-based screen
display developed for use by the nuclear power plants of electric power
companies and has deployed a detailed workflow function that corresponds
to the radiation control. This system was installed at the
Tomari Power Station of Hokkaido Electric Power Co.,Inc. in March
2003, and enables the user to drastically reduce administrative paperwork,
which including filings and notifications. Moreover, the capability
has been provided for partner companies to extract company data in
their desired format. Additionally, monitoring functions have been
strengthened and an auto-alarm function provided in case of error with
the system's status or managed data.
Radiation Monitoring System
Masaaki Satou, Hiroyuki Mizuno, Takashi Yabutani
This paper introduces a radiation monitoring system for use at
facilities such as universities, hospitals and research laboratories
where radioisotopes (RIs) are used. RI used by medical institutions and
research laboratories has increased in recent years. Meanwhile, as
society becomes more concerned about the environment, radiation
monitoring systems are becoming increasingly important. An overview
of this system and recent trends are provided.
Industrial Measurement Instruments that Use Radioisotopes
Asao Monno
An example of a large-scale system for controlling hot rolling, and
recent developments for a gamma-ray thickness gauge for the innermill
housing of a plate and a thickness gauge for a hot seamless tube
mill are introduced. The dramatically higher speed response, versatile
intelligent elements, larger data capacity and formation of a database
are advantages of these instruments over conventional devices.
Moreover, Fuji Electric's industrial measuring instruments that use
radioisotopes are manufactured and marketed to be compatible with
those of Hitachi, and we have already compiled a track record of many
deliveries.
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