On December 19, 2019, Japan Toray Industries Co., Ltd. released a polyphenylene sulfide (PPS) film that maintains excellent dielectric properties and chemical stability of PPS polymers.
This film is a polyphenylene sulfide (PPS) film suitable for 5G circuit substrates. Compared with ordinary PPS films, its heat resistance is also increased by 40 ° C.
It will not be deformed under heating test at 250 ℃, plus dimensional stability and dielectric characteristics, Toray will use these characteristics as product requirements, in order to obtain flexible printed circuit board (FPC) for high-speed transmission use.
At this stage, the PI with a dielectric loss of 0.008 is the main antenna material, but in the 5G era, the dielectric characteristics of PI are slightly insufficient. The LCP with a dielectric loss of 0.002 is the most concerned antenna material at present. Excellent, but the LCP dielectric performance reduces the transmission loss in the high frequency band, and this film can also produce thermal resistance when soldering the circuit board.
At the same time, LCP costs are high, and there are still issues in processability.
The R & D staff therefore turned their attention to PPS with a dielectric loss of 0.002. The unique technology to control the crystal structure greatly improves heat resistance.
There is a reflow soldering process when making FCP. The heating temperature is 200 ~ 250 ℃. The past PPS film is heated at 250 ℃. The thermal shrinkage rate is 3.9%, and the new product is 0.5%. And the reflow soldering test was carried out in the state of the printed circuit board, and it was found that the previous PPS film curled and deformed did not occur in the new product.
In response to this new type of PPS film, Toray plans to build a mass production system in 2020 and realize revenue of 2-30 billion yen in 2025.