DNP Develops Low Profile and Light-Weight Sheet-Type Coil for 11.1kW of High-Power Wireless Charging of Electrified Vehicles

Dai Nippon Printing Co., Ltd. (DNP) has developed a low-profile, light-weight, and low cost sheet-type coil that supports 11.1kW of high-power wireless charging for electrified vehicles and Automatic Guided Vehicles (AGV). Such vehicles include Electric Vehicles (EV), and Plug-in Hybrid Electric Vehicles (PHEV).


In recent years, amid the global penetration of electrified vehicles aimed at lowering environmental burdens, wireless charging technologies that eliminate the complexity of the charging process and improve consumer convenience, have come under the spotlight as a means to further promote the spread of electrified vehicles. Wireless charging is now considered to be as essential a technology as automatic parking. Having said that, existing coils that utilize litz wire as a conductor present the challenge of high-profile, weight, and cost.  

In answer to these challenges, DNP has developed a sheet-type coil with a lower profile, lighter weight, and lower cost than existing product. The new product leverages coil design and manufacturing technology, based on knowledge built up in the electronics division over a period of many years. It supports high power transmission in the J2954-WPT3/11.1kW class as laid down by the Society of Automotive Engineers (SAE) International*1. Apart from EV and PHEV, can also be used with AGV, for which the market is expanding.

*1: According to the organization’s website, “SAE International is a global association of more than 128,000 engineers and related technical experts in the aerospace, automotive and commercial-vehicle industries.”

Sheet-type coil that supports high-power wireless charging

Charging image

New Sheet-Type Coil Features

  • Supports wireless charging systems on both the transmission and reception sides.
  • Coil thickness, including the ferrite for electrified vehicles purposes, is approximately 3mm, with a weight of about 1kg (in the case of J2954-WPT3/Z2 compatible coil as laid down by the SAE International). According to DNP in-house research, the new coil achieves significantly lower profiles and weight saving of approximately 75% compared to currently available products of similar specifications that use litz wiring, where the thickness is approximately 12mm, with a weight in excess of 4kg. 
  • As it is possible to reduce the amount of materials in use, cost savings can also be achieved compared to currently available products. 
  • High power transmission has been achieved by leveraging DNP’s proprietary coil design technology to reduce magnetic field leakage and equalize heat generation.
  • By taking advantage of optimal design technology matching the coil size and power consumption, it is also possible to use the new coil with AGV with restricted installation space. 
  • The new product can be used as a built-in coil in IH home appliances that convert the magnetic field generated by the coil into heat.

Looking Ahead

DNP will promote the early commercialization of the newly developed sheet-type coil that is compatible with high power charging, aiming for sales of 5.0 billion yen (approximately USD 45.8 million) a year by 2025. We will propose the new coil to AGV and IH home appliance manufacturers along with car and system makers both in Japan and overseas. We will also propose the new product to the infrastructure industry, such as road builders. In addition, we will strive to apply and further develop sheet-type coil technology, and further promote product development. In the future, we will expand the uses of the new sheet-type coil product so as to include dynamic wireless charging that is presently the focus of R&D in a variety of countries around the world.

*Company names, products and service names appearing in this release are the trademarks or registered trademarks of those companies.
*Product information and service details described in this release are accurate as of the date of issue. They are subject to change without notice. 

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