Fujitsu Semiconductor achieves 2.5kW output in server power supply units
22 Nov 2012
Fujitsu Semiconductor Asia Pte Ltd (FSAL) disclosed on Tuesday that it has successfully achieved high output power of 2.5kW in server power supply units equipped with gallium-nitride (GaN) power devices built on a silicon substrate. 
The company said that it aims to start volume production of the GaN power devices in the second half of 2013. These devices will enable Fujitsu Semiconductor to propose their use in a wide variety of value-enhancing power supply applications, significantly contributing to the realisation of a low-carbon society.
The company is targetting approximately 10 billion yen in sales of GaN power devices in fiscal 2015.
Compared to conventional silicon-based power devices, GaN-based power devices feature characteristics such as lower on-resistance and the ability to perform high-frequency operations.
These characteristics are expected to contribute to improvements in the conversion efficiency of power supply units and make them more compact.
Fujitsu Semiconductor is aiming to commercialise GaN power devices on a silicon substrate, which, with increases in the diameters of silicon wafers, enables low-cost production, for which the company has been developing technology for volume production since 2009.
In addition, the company has provided specific power supply-related partners with sample GaN power devices since 2011 and has worked on optimizing them for use in power supply units.
Recently, in a collaborative effort together with Fujitsu Laboratories Limited, Fujitsu Semiconductor has been working on technical development initiatives, such as developing a process technology for growing high quality GaN crystals on a silicon substrate, developing device technologies, such as optimising the design of electrodes to control the rise of on-resistance during switching, and devising a circuit layout for power supply units that can support the high-speed switching of GaN-based devices.
These results have enabled Fujitsu Semiconductor, in a test circuit using a GaN power device, to succeed in achieving conversion efficiency that exceeds the performance of conventional silicon devices. Fujitsu Semiconductor also prototyped a power supply unit for servers equipped with a GaN power device for the power factor correction circuit and successfully achieved output power of 2.5kW.
Fujitsu Semiconductor says it views its success in these results as opening a path to high-voltage, large-current applications for its GaN power devices. 
The company has recently completed setting up a mass-production line for 6-inch wafers at its Aizu-Wakamatsu plant, and will begin full-scale production of GaN power devices in second half of 2013.
Moving forward, by offering GaN power devices optimised for customer applications and technology support for circuit designs, Fujitsu Semiconductor will support the development of low-loss, highly-compact power supply units suited to a wide range of uses. Fujitsu Semiconductor is aiming to achieve approximately 10 billion yen in sales of GaN power devices in fiscal 2015.
