Development of the“ CEE-950” Thin Film Encapsulation Equipment for OLEDs

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3.System composition of Thin Film Encapsulation Equipment for OLEDs

In order to form laminated films for thin film encapsulation, the system is equipped with a PECVD-based SiNx deposition chamber and an acrylic deposition chamber using the vaporization method. These are shown in Figure6. Located in the periphery of the core chamber mounted with a substrate-transfer robot are 4 SiNx deposition chambers, 2 acrylic deposition chambers, 1 load chamber and 1 unload chamber. When processing materials at our recommended film thickness (SiNx/Acrylic/SiNx=400 nm/250 nm/400 nm) with this configuration, production with a tact time of 180 seconds can be realized. The SiNx deposition chamber is a plasma CVD unit with built-in 27.12 MHz parallel planar electrode, and has process characteristics including the excellent barrier property described before. In addition, it has a high capacity with a deposition rate of no less than 400 nm/min and a distribution within ±5% for the G4.5 class (excluding the 10 mm at the edge of the substrate), and enables deposition of SiOxNy film and SiOx film depending on the device configuration.
When using a pattern mask, an alignment mechanism with a performance of ±3 μm, which is achieved using a CCD camera, can be mounted.
The acrylic deposition chamber performs the two different processes of deposition and curing in a single chamber. It is equipped with a deposition unit at the bottom and a UV lamp unit for curing at the top, and is characterized by its very compact structure compared to other companies’ equipment. It is highly capable with a deposition rate of no less than 700 nm/min and a distribution within ±6% for the G4.5 class (excluding the 10 mm at the edge of the substrate).

Figure 6 System composition.

Figure 6 System composition.

4.Conclusion

The technology introduced in this paper can provide over 500 hours of durability under a high temperature and high humidity environment at 60℃ and 90% RH with our recommended film thickness (SiNx/Acrylic/SiNx=400 nm/250 nm/400 nm).
Looking ahead, with the aim of commercializing nextgeneration flexible devices, it is required for encapsulation technology to provide high encapsulation performance and high bending characteristics. Our Chigasaki Head Office/Plant possesses a G4.5 demonstration unit for verification equipped with a SiNx deposition chamber and acrylic deposition chamber (as introduced in this paper), and we continue to develop it in the future as well.

*This article was released in “Technical Journal No.79 published in June, 2015”

For further infomation

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Yuuko KATOU*1, Takahiro YAJIMA*1, Kensuke SEI*2, Makoto AODAI*2, Shougo OGURA*2, Tadashi OKA*1, Katsuhiko MORI*1 and Satohiro OKAYAMA*1
*1 FPD・PV Division, ULVAC, Inc., 2500, Hagisono Chigasaki, Kanagawa, 253-8543, Japan
*2 Institute for Super Materials, ULVAC, Inc., 2500 Hagisono, Chigasaki, Kanagawa, 253-8543, Japan
To produce flexible next generation displays, it is essential to apply thin films that have excellent encapsulation properties against moisture. We have already developed SiNx film as an encapsulation film, and with it we achieved a WVTR value of 5E-5g/m2/day using the Ca method. Now we have developed a technology with excellent particle coverage by layering SiNx film and acrylic using laminated film deposition.