DIC and Unitika Collaborate to Develop a Specialty PPS Film with Low Dielectric Properties Suitable for Use in a Key Material for Millimeter-Wave Printed Circuit Boards and Millimeter-Wave Radar

Tokyo, Japan—DIC Corporation announced today that it has developed a new specialty polyphenylene sulfide (PPS) film in collaboration with Japanese firm Unitika Ltd. that suppresses transmission loss at high frequencies. This product’s low dielectric properties make it suitable for use in a key for millimeter-wave printed circuit boards compatible with next-generation communications devices and for millimeter-wave radar. This new PPS film has already been evaluated by a number of electronics materials manufacturers and preparations are currently being made to commence commercial production.

Conventional high-frequency flexible printed circuit boards used in smartphones and small electronic devices, among others, are fabricated by bonding layers of liquid crystal polymer (LCP) film and copper foil. LCP creates in an uneven film–copper foil adhesive interface, a cause of higher transmission loss. Because next-generation communication devices use the millimeter-wave frequency band (30 to 300 GHz), they require materials with low dielectric properties, which minimize transmission loss.

The specialty PPS film developed by DIC and Unitika combines the former’s proprietary PPS polymerization and compounding technologies with Unitika’s film manufacturing technologies. This new film maintains the low moisture absorption, as well as the flame and chemical resistance, of PPS resin, while delivering the outstanding low dielectric properties, dimensional stability, reflow resistance and uniformity of thickness required for high-frequency printed circuit boards. In particular, this product demonstrates stable dielectric properties in high-temperature environments and at a wide range of frequencies (10 to 1,000 GHz), a performance feature difficult to achieve with LCP or other common films, as a result of which it is expected to be adopted for a wide variety of applications, from smartphones to automobiles.

This new film also boasts excellent adhesiveness with different materials, meaning that it is compatible with a broad range of flexible copper clad laminate (FCCL) processing methods, including sputtering and plating,* as well as lamination with an adhesive. The sputtering and plating method, in particular, delivers a smooth adhesive interface that achieves lower transmission loss than commonly used films, including LCP or fluoropolymers.

*　The sputtering and plating method involves using vacuum sputtering to deposit particles of metal such as nickel or copper on the film surface to form a conductive seed layer and then electroplating to create a conductor layer of the required thickness.

The DIC Group is contributing to digitalization by developing functional materials that anticipate emerging needs in the development of infrastructure for next-generation communications, including 5G/6G, and generative AI, which are expected to see accelerated demand in the years ahead.

Unitika will display this new PPS film at its booth at the 15th FILMTECH JAPAN exhibition, which will be held at Makuhari Messe in Chiba from October 29 to 31, 2024.


Exhibition details
Name: 15th FILMTECH JAPAN (Part of the 15th Highly-functional Material Week)
Dates and times: October 29–31, 2024, 10:00–18:00 (17:00 on the last day)
Venue: Makuhari Messe (1, Nakase 2-chome, Mihama-ku, Chiba)
Unitika’s booth: Exhibition Hall 5 (24–25)
Organizer: RX Japan Ltd.
Official website: https://www.material-expo.jp/hub/en-gb/exhibit/film.html

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About DIC Corporation
One of the world’s leading fine chemicals manufacturers and the core of the DIC Group—a multinational with over 180 subsidiaries, including Sun Chemical, in over 60 countries and territories—DIC is a global leader in products essential to modern life, from packaging materials and TV/PC display materials to high-performance materials for smartphones and other digital devices and automobiles. With annual sales of over one trillion yen and 22,000+ employees worldwide working together with customers everywhere, DIC delivers safety and peace of mind, contributing to a sustainable society with innovative products that respond to social change and social imperatives.
For more information, please visit the DIC global website https://www.dic-global.com/.

Commercial Contact:
DIC Chemitronics Business Division
E-mail: chemitro-ppsfilm@ma.dic.co.jp