This new electromagnetically transmittable film coating technology uses a special material on the surface of the material to form a base layer of an organic film, coating this with chromium using a method called sputtering. When this is heated, stress differences occur due to differences in the thermal expansion coefficients of the organic film and the chromium film, and extremely fine cracks are generated in the chromium film. These cracks allow transmission of electromagnetic waves, including millimeter waves.
Kimoto Co., Ltd. and the Kanto Gakuin University Materials & Surface Engineering Research Institute have jointly developed technology for the formation of the base layer of the organic film using a special material. The application of this special material and the chromium sputtering were performed using equipment and technology of Shimadzu Corporation. JCU Corporation proposed applying this film coating process for use in automobile emblems.
Performance evaluations of the electromagnetically transmittable film have confirmed that the attenuation rate of electromagnetic waves can be kept low. Compared with the existing method that uses indium, the electromagnetic wave attenuation rate is about the same, whether the frequency is the 76/77 gigahertz band used in existing millimeter-wave radar or the 79 gigahertz band that is expected to be adopted in future, while cost savings of up to 50 percent can be achieved.