Characteristics of Transparent Conductive Films

Transparent conductive films have the function of transmitting both electricity and visible light.  ITO (Indium Tin Oxide) has been widely used as a transparent electrode for various applications, such as touch displays or solar battery cells.

ITO generally having a resistance of 10s or 100s Ω/sq., in order to meet the demand for lower resistance required in recent years ITO has to be applied thickly, however that causes problems like transmissivity loss or color change (yellowing).

To solve these problems, metal mesh has been developed as an alternative of ITO.

Conventional Etching Type Metal Mesh

Etching method is generally used to produce metal meshes, but there is a trade-off between lower resistance and finer wiring lines. When large size is required, transmissivity is sacrificed by the increased line width in order to lower the resistance.

In addition, metal remainder at the cross point, which tends to happen in the metal mesh produced by etching process, causes deterioration of appearance.

Industry’s First^*1 Unique Roll to Roll Process

Panasonic has developed a double-sided full wiring metal mesh using industry’s first^*1 unique roll-to-roll process to achieve high wiring aspect ratio, realizing low resistance and high transmissivity at the same time.

Wire thinning and Aperture Ratio

Wire thinning greatly contributes to the aperture ratio.
Since a metal blocks light, the narrower the metal wiring line width is, the greater the aperture ratio becomes.
Aperture ratio is proportional to the transmissivity, therefore Panasonic’s metal mesh films can achieve high transmissivity.

Visibility of Wiring Lines

Metal wiring lines are visible due to metal reflection if the line width is not thin enough.
In Panasonic’s metal mesh, wiring line width is 2 um or less so mesh pattern is invisible to human eyes.

➀ Transparent Antenna

Since 5G/6G tele-communication uses high frequency bands, it is strongly affected by various substances and devices nearby.
Therefore, the placement of 5G/6G antennas is less flexible, and ideally they should be placed on the top surface of devices.
Transparent antennas, utilizing Panasonic’s transparent conductive film technology, can be placed anywhere without disturbing the design and function of displays, windows etc.

Transparent pattern using fine wire mesh that achieves performance equivalent to a metal antenna​

② Meta-surface

High frequency radio waves propagates in a straight line, so radio waves cannot reach in long distance, especially in the areas where buildings are densely concentrated.
For this reason, there is a need for metasurface devices, such as reflectors that propagate radio waves in far distance, and lenses that draw radio waves into the room.
Panasonic contributes to 5G/6G world by applying its transparent conductive film to metasurface technology.