Thin receiving coil for wireless power transfer targets mobile devices

July 13, 2012 // By Jean-Pierre Joosting
TDK Corporation developed a wireless power transfer coil unit designed for smartphones and other mobile devices, that features an industry-leading thickness of only 0.57 mm.

The development reflects the company's extensive expertise in fields such as magnetic materials technology and process technology, and involved the creation of a unique, extremely thin and flexible metal magnetic sheet. As a result, the coil unit not only is ultra thin and lightweight, it also is highly resistant to shock and therefore provides excellent reliability.

In spite of its 0.57 mm profile, the coil's design minimizes the tendency towards rising resistance and achieves a power transfer efficiency that clears the requirements of the WPC "Qi" standard. At this point, output current is of the order of 0.5 to 0.6 A, but an even thinner 0.50 mm type with equal or better output current is already in development, with a view towards starting mass production in 2013.

As smartphones incorporate more and more functions, their power consumption also tends to increase, making charging of the battery a more frequent requirement. With the aim of establishing an infrastructure environment that allows easy charging anywhere at any time, the WPC and other promotional organizations are working towards the standardization of wireless power transfer.