Foxconn enticed by Sharp's IGZO display technology
ATSUNOBU TAKESHITA, TAKASHI KUROKAWA, Nikkei staff writers
TOKYO -- Taiwanese electronics tycoon Terry Gou was so enchanted by Sharp's cutting-edge display technology that he had no second thoughts about buying the embattled Japanese maker when the opportunity arose.
The display technology that led the chairman of Hon Hai Precision Industry, better known as Foxconn, into signing the $3.5 billion deal to acquire Sharp uses the clunky name IGZO, from indium gallium zinc oxide.
At a press conference after the inking of the takeover deal on April 2, Gou crowed about the advantages of IGZO over the amorphous silicon used in conventional liquid crystal display panels. IGZO screens provide more detailed images while using less power, and this next-generation display technology will help secure successful products in a highly competitive market, he said.
Display resolution and power consumption are crucial to customer satisfaction.
What's behind it?
IGZO is a semiconductor material used in making a backplane, which controls the pixels that create images by shooting electric signals to turn pixels on and off. It consists of a material and an assembly design used for the thin-film transistors that drive the main display. The backplane contains an array of transistors responsible for activating the individual pixels.
Backplane technology is a determining factor in a display's resolution and power use.
Electrons move 10 to 30 times faster in IGZO than in amorphous silicon. That means the transistors can be made much smaller, allowing for smaller pixels, which then translate into higher resolution and lower power consumption.
IGZO-based displays consume 30-40% less power than conventional LCD displays, making it possible for devices such as smartphones to run longer on one battery charge.
In 2012, Sharp became the world's first maker to launch smartphones using IGZO-based LCD panels. They are now used in tablets as well. Sharp is currently working to apply IGZO into organic light-emitting diode panels.
Sharp may have made the breakthrough in large-scale manufacture of IGZO panels, but the display technology was made possible by nearly three decades of work by Japanese researchers.
It has its roots in groundwork done by Noboru Kimizuka, who belonged to the National Institute for Research in Inorganic Materials (currently the National Institute for Materials Science). Kimizuka synthesized IGZO for the first time and published a paper on the semiconductor in 1985. He cleared up its crystal structure in 1995.
Then, Hideo Hosono, a professor at the Tokyo Institute of Technology, hit upon the idea of using IGZO for making displays. He realized IGZO could significantly improve the performance of panels by replacing silicon in the manufacture of TFTs, because IGZO is a semiconductor with higher electron mobility.
Hosono made a prototype of these TFTs in 2002 with the support of the Japan Science and Technology Agency. In 2003, he proved IGZO is superior to silicon for making TFTs. After Hosono published a paper on his research in the science journal Nature in 2004, the acronym IGZO became a buzzword in display technology circles.
Leading South Korean display manufacturers, such as Samsung Electronics and LG Electronics, were quick to start applying IGZO to displays. But their Japanese rivals were mostly lukewarm about the technology, Hosono said. Sharp was one of the few Japanese makers that showed serious interest in it.
All of the dozens of IGZO patents are owned by the Japan Science and Technology Agency. In 2012, Sharp concluded a patent licensing agreement with the agency and then set about developing IGZO-based displays. But it was not an agreement for exclusive use: Samsung had struck a similar deal with the Japan Science and Technology Agency in 2011.
However, there are uncertainties surrounding the future of Sharp's IGZO display technology due to the company's acquisition by Hon Hai. It is not yet clear whether the licensing agreement will remain valid now that a Taiwanese company owns Sharp.