Executive Officer, Group President, Semiconductor & Device
In order to achieve sustainable societies, it is imperative to use generated power while minimizing power loss in the process. Power semiconductor devices are incorporated into a number of power electronics, playing a significant role in reducing power loss. In addition, Mitsubishi Electric manufactures state-of-the-art products using silicon carbide (SiC) as a means of helping to create low-carbon societies.
The Semiconductor & Device Group provides high-performance, high-efficiency, compact high-frequency devices and optical devices for wireless communications equipment and optical fiber communications that make full use of multiple semiconductor technologies. Furthermore, by reducing the space required for communications equipment, the cooling function can be simplified, thereby contributing to comprehensive energy savings.
Industrial-use TFT color LCD modules provide a mercury-free, low-power consumption option owing to the white LED backlight used in them. We have an extensive lineup of LCD modules that are used in measuring equipment, construction and agricultural machinery, machine tools, and POS terminals.
In addition to providing these products, the Semiconductor & Device Group is working to reduce negative environmental impact during production. We are continuously and proactively reducing energy use through measures such as installing high-efficiency air conditioners in cleanrooms where high levels of cleanliness require a large amount of energy, improving wafer processing operations, and reducing the emissions of non-CO2 greenhouse gases (SF6, HFC, and PFC) through the introduction of detoxifying equipment.
Focusing on the SDGs
Mitsubishi Electric is developing semiconductor devices using silicon carbide (SiC), the material physical attributes of which can significantly contribute to reducing power loss, and expanding the product lineup.
In fiscal 2011, we were the first company in the world to equip air conditioners with SiC power semiconductor modules. Since then, we have promoted their use in various products such as rolling stock and industrial equipment. In March 2017, we launched the SiC-SBD*1 (discrete), which reduces power loss by approximately 21%*2 compared to our conventional products. It contributes to improving the efficiency and reducing the size of electric vehicle power supply systems used for charging batteries, photovoltaic power systems, air conditioners, and more.
We will continue to accelerate the development of new technologies and products to respond to diverse needs for energy efficiency.
25 Gbps EML CAN
Data transmission volume has been rapidly increasing with the widespread use of handheld mobile communication devices and the storage of information on cloud networks. In response to these trends, the construction of large-volume, high-speed optical communications systems is being planned between base stations where traffic is concentrated and exchanges where communication signals from base stations are centrally controlled. In November 2018, Mitsubishi Electric launched a new optical communications device that is used to connect the base stations in such networks. The 25 Gbps EML CAN has improved the speed and volume of mobile communications systems and reduced energy consumption, thus contributing to energy efficiency.
Mitsubishi Electric Transflective Series Color TFT-LCD modules
(Left: 8.4-inch VGA, right: 10.4-inch XGA)
Transflective Series TFT-LCD modules*6 use outside light as a light source in bright outdoor environments (in reflective mode) and as backlight in dark places (in transmissive mode). Because of their high visibility, even in direct sunlight, and lower power consumption owing to the use of outside light, demand is mounting for use in portable industrial measuring equipment. Expansion of the product lineup will help reduce power consumption of displays installed in a wide range of industrial devices used outdoors.
In addition to contributing to society through our business operations, we are striving to reduce the negative environmental impact stemming from our business activities. Some of the initiatives we are implementing are as follows.
The manufacturing of semiconductors and devices is conducted in cleanrooms under rigorous temperature, humidity, and cleanliness controls to ensure product quality and reliability. Maintaining such a high-level cleanroom environment requires air-conditioners that consume as much energy as production equipment. These circumstances led to our decision to take every possible step to reduce energy consumption; for example, by replacing conventional air-conditioners with high-efficiency units and improving the efficiency of wafer processing equipment.
The Power Device Works at the Kumamoto site has changed over to higher efficiency air-conditioners and integrated management, resulting in a 16.6 million kWh (equivalent to 7,000t of CO2) reduction in annual electricity consumption.
A rooftop photovoltaic system with a rated power output of 300 kW has been installed at Power Device Works in Fukuoka, resulting in a total reduction in consumption of approximately 290,000 kWh (equivalent to 120t of CO2) per year.
The LCD Division uses nighttime power to create ice for its ice-based thermal storage system. Cold energy stored in the ice is then used for air-conditioning. This system helps us reduce the division's electricity usage and realize a peak shift in response to requests from Japanese government and power companies.
At the Power Device Works and High-Frequency & Optical Device Works, we have been systematically moving towards LED lighting. In fiscal 2016, we installed practical-use LED yellow lamps, which affect manufacturing conditions, for verification purposes as well. This realized a 650,000 kWh (equivalent to 275t of CO2) reduction in annual electricity consumption. Further conversions to LED lighting are planned for the future.
The design technology building at the Fukuoka-based Power Device Works is equipped with various environment-conscious features, including Mitsubishi Electric's own Facima system, which controls and manages energy consumption. This building has been recognized for its high environmental performance and was awarded the highest evaluation of "S Rank" under Fukuoka CASBEE*, a system that evaluates the environmental performance of buildings. Moreover, a new technological control building for the LCD business also earned the recommendation rank of "A (very good)" under Kumamoto CASBEE in recognition of its high environmental performance.
Semiconductor production factories use large volumes of pure water. From the viewpoint of preventing further depletion of water resources, we are making efforts to reuse pure water. As part of this, we ensure removal of organic and inorganic contaminated impurities contained in the wastewater, and have established a system to process and recycle effluent.
In order to quickly and accurately respond to customer inquiries related to information on the environmental impact of our products, we have introduced a chemical substances management system.
We started a biological research project involving animals and plants at our Power Device Works and High-Frequency & Optical Device Works in fiscal 2016. As a result of examining the animals and plants living at these sites with expert guidance, we were able to confirm the presence of many regional endemic species, including some living organisms designated as endangered species. We are conducting activities designed to improve the habitat of these local species.
Additionally, we produced a living creature guide at Power Device Works and distributed it to nearby elementary schools and neighborhood community associations. We are also working to live in harmony with the local communities, giving due consideration to biodiversity.