Transparent, High-Resistant Film Suits 5G Communications

Toray Industries, Inc. has developed a new film for 5G communications, offering excellent transparency, heat-resistance, flame-retardancy, and dielectric performance.

The highly transparent film caters to a wide-ranging applications. These include transparent 5G antennas, transparent flexible printed circuit boards, transparent heater substrate materials, and other electronic components. Construction materials also benefit from the film’s transparency and flame retardancy, and process release films requiring chemical and heat resistance to ensure visibility for inspections and positioning. The company has begun providing samples to users, and will keep pushing ahead with R&D to accelerate commercialization.

Conventional film (left) and highly transparent polyphenylene sulfide film (right)

Need for Transparent 5G Antennas

5G technology offers ultra-fast communications for broadband cellular networks, but also requires numerous antennas. That is because it uses higher frequency radio waves with short ranges. This situation propelled efforts to explore transparent antennas with good visibility and design.

Existing transparent circuit boards employ polyethylene terephthalate film and transparent polyimide film because they are light and unbreakable. However, their dielectric loss tangent are high, causing large signal losses in 5G communications.

Torelina PPS Film

The existing Torelina film by Toray is ideal for 5G circuit boards. It banks on outstanding heat resistance, flame retardancy and electrical insulation. It has consistently low dielectric loss tangent in varying temperature and humidity conditions. Torelina is the only bi-axially oriented polyphenylene sulfide film available.

Polyphenylene sulfide is a super engineering plastic with outstanding chemical resistance, flame retardancy, electrical insulation, and long-term heat resistance. This crystalline resin has a melting point of 280°C.

However, the film is opaque, with the typically yellow tinge of heat-resistant polymers. That is because tiny voids inside the film scatter light and result in low transparency.

Eliminating Voids

Toray combined its polymer design and proprietary particle dispersion technologies to eliminate these voids. It reduced the yellow tinge and significantly increased film transparency without compromising performance benefits. This highly transparent polyphenylene sulfide film has a haze comparable to that of polyethylene terephthalate film.

Haze refers to the degree of light scattering. A lower haze means less scattering and greater material transparency.

When the new film is used in transparent 5G antennas, it would help stabilize 5G communications. This is done by cutting signal losses under different temperature and humidity conditions and improve visibility and design.

Toray will pursue the research and development of advanced materials that transform societies. It is committed to innovate ideas, technologies, and products that deliver new value. The company will continue to leverage its core technologies of synthetic organic and polymer chemistry, biotechnology, and nanotechnology.