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The Total Solution Exhibition for Electronic Equipment 2021 (October 27-29)


The Total Solution Exhibition for Electronic Equipment 2021
New proposals for flexible device are cranked-up

October 27-29, The Total Solution Exhibition for Electronic Equipment 2021 was held in Tokyo Big Sight. Main topics in this exhibition are picked up.

Dedicated blade edge was developed for flexible glass of NEG

Yamagata University exhibited OLED lighting devices using ultra-thin flexible glass "G-Leaf", which was developed by Nippon Electric Glass (NEG). In this device, all layers inclusive of electrodes and organic layers were deposited continuously by the Roll to Roll method. If G-Leaf is used as a substrate, flexible OLED with high mechanical strength and gas barrier property can be easily manufactured.


Picture 1. Variant OLED
In this time, manufactured mother-glass was cut at device size by using a specific blade edge "SOLID-D", which was developed by Mitsuboshi Diamond Industrial. It's a dedicated cutting tool for G-Leaf by optimization of hardness and surface condition of diamond blade. If typical diamond blade edge and laser scribe technology are used as scribe method, clacks often occur in the neighborhood of cutting plane. On the other hand, if SOLID-D is used, clack does not almost occur. In short, after scribe and break, strain is not generated inside of the substrate. For this reason, after manufacturing of the flexible product, high bending strength is obtained. Of course, it's unnecessary to bevel cutting cross-section surface after break.

Its scribing speed is 100㎜/sec. The company is releasing a dedicated cutting system "MUGP9010" and SOLID-D. By the way, MUGP9010 is a sheet type system, but Roll to Roll type system has been developed yet.

As picture 1, a variant OLED was exhibited in the booth. The project group indicated that this technology was effective for not only simple cutting, but also variant fabrication.

Roll-to-Roll type direct imaging system is practical use for long FPCs


Picture 2. Wire harness and long FPC
With respect to equipment system, Inspec introduced a Roll-to-Roll type direct imaging system for long FPCs. In this system, substrate is directly patterned by using semiconductor laser (405nm). Therefore, it's possible to pattern seamlessly. In the latest system, it's possible to correspond to 250㎜ in width and 6m in length. Imaging speed and resolution are 35mm/sec and L&S＝100μm/100μm respectively.

As picture 2, the company exhibited wire harness and long FPC in the booth. Firstly, the company proposes this system in the automobile system for long FPCs, which is replacer of wire harness.

Upper ITO electrode can be used to organic device by relaxation of stress in deposition process

As concerns manufacturing process, National Institute of Advanced Industrial Science and Technology (AIST) appealed degradation of characteristics of organic devices could be avoided by relaxation of stress in ITO electrode deposition process.


Fig.1 J-V curves of transparent OLED1)
In deposition process of upper ITO electrode, H2O gas was purged into the vacuum chamber at approximate 10-4Pa due to block of poly crystallization of ITO film. As a result, ITO film became to be amorphous, and then, stress in ITO film was reduced.

Therefore, a transparent OLED with upper ITO transparent electrode was pilot-produced. Its device was composed of ITO anode/NPB/Alq3/LiF:MgAg/ITO cathode. In proportion as reduce of stress in ITO film, as figure 1, J-V curves of device was enhanced.

Epoxy film becomes to be a candidate of newly transparent plastic film

As regards material, Mitsubishi Chemical exhibited an epoxy film as a new transparent plastic film. Various inks, pastes, and liquids can be directly coated and printed on this film without buffer layer because of high adhesiveness, which is essential property of epoxy resin. Furthermore, thermal resistance is superior because of Tg free. Transmittance and coefficient of thermal expansion are approximate 85% and 54 - 71ppm respectively.


Picture 4. Distributed type inorganic EL

Picture 3 Epoxy film
Compared to epoxy film and the conventional PEN film with printed Ag Nano wire in bending test at R＝1㎜, bending strength of the former was higher than that of the latter. In the booth, a distributed type inorganic EL (PEDOT/Ag grid electrode/ZnS+polymer/BaTiO3+polymer/rear electrode) using this film was exhibited. The company supplies roll type sample (maximum 900㎜ in width) for various flexible devices.

Reference
1)Suemori, et.al.：Controlling the internal stress of ITO layer for improving the performance of transparent organic light emitting diode , The 82th JSAP Autumn Meeting, 2021, 11-286 (2021.9)

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