What is the optimal encapsulation technology for the Flexible AMOLED?

Currently mass-producing flexible AMOLED panels are taking PI substrate, backplane, and RGB deposition method, and the existing encapsulation technologies for A2 line of Samsung Display is TFE (thin film encapsulation) and hybrid encapsulation for LG Display.

But for the flexible AMOLED exclusive A3 line which is newly invested by the Samsung Display, advanced the orders not in the TFE but in the hybrid encapsulation method which is laminating the film after resin coating process on the passivation structure of inorganic layer and organic layer, similar to the method that the LG Display takes.

The reason for the change of encapsulation technology at the A3 of Samsung Display was analyzed in the “2014 Flexible OLED Report” issued by the UBI Research including the latest trends and issues such as the flexible AMOLED related issues and processes, market forecast of the flexible AMOLED panel and flexible OLED lighting, flexible AMOLED technologies comparison of Samsung Display and LG Display, etc.

According to this report, the flexible AMOLED panel market is forecasted to show a compound annual growth rate of about 60% through to 2020, reaching $ 17,600 million where the primary applications are expected to be for the flexible AMOLED panel of tablet pc.

140926_Flexible AMOLED용 encapsulation, 최적의 기술은

<Flexible AMOLED panel Market Forecast>

reporter@olednet.co.kr

OLED TV cost saving, the alternative is co-planar structure

Current AMOLED panel market is mainly led by either Samsung Display or LG Display, mass producing the LTPS backplane for mobiles and Oxide backplane for TVs.

 

Though the AMOLED panel market for mobiles has established stable position in the business beyond LCD panel market, the market for TV is having difficulties in settling for its high price compared to the LCD/LED TV, requiring pressing technological development to lower the cost.

 

As a counterplan for this, the LG Display received a considerable attention at the SID 2014 by exhibiting 65-inch curved UHD OLED TV applying not the existing etch stopper layer (ESL) structure but the co-planar structure.

 

According to the “2014 AMOLED Backplane Technical Report” published by the UBI Research, it was analyzed that there is a difference in the investment expenses by about $ 80 million when making the additional investment in oxide TFT AMOLED line of co-planar for a-Si LCD line against the supplementary investment in oxide TFT AMOLED for LCD line. (For Gen 8) It was also suggested that the co-planar structure is appropriate for the oxide TFT structure which can make the best use of the backplane and color filter equipment of the previous a-Si LCD line as the mask can be used under 6 layers.

 

In addition, the core issue of the AMOLED industry which is a technological concern over the flexible LTPS applied to the flexible display was examined along with the latest technology trend analysis of LTPS, oxide, and organic TFT in the “2014 AMOLED Backplane Technical Report”.

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reporter@olednet.co.kr

KITECH, Developed the world’s first refining technology for organic light-emitting material using ILs for OLED TV

Dr. Taewon Kim’s team of photovoltaic energy convergence research group of Korean Institute of Industrial Technology (KITECH, President Yong-Soo Lee) developed an original technology to refine organic light-emitting materials in bulk for fine OLED TV at low price.

Dr. Kim’s team established a new concept for the refining technology by using Ionic Liquids (ILs), and it can solve issues of high cost·low yield rate arisen in production of the organic light-emitting material for the OLED TV.

Ionic Liquids are liquids that only consist of positive and negative ions at room temperature and stays in liquid form at high vacuum (~100℃) with almost no volatility. Recently, ILs became a future clean solvent in green chemistry field with a strength of good solubility for high molecular substance and a feature of metal salts.

Until now, ‘sublimation refining method’ has been used to get high purify organic light-emitting material by utilizing the difference of sublimation points between vaporization and solidification of a material. However, cons of this method are low yield rate and very high production cost because it is impossible to realize complete auto and continuous process.

To address this issue, Dr. Kim’s team started developing the large scale refining technology for the organic light-emitting materials at low cost since 2011 and applied for original patent in December, 2012. Their effort on verifying the possibility of the technology’s application produced this result in 19 months.

The key of the result is the application of the high purity refining technology on the organic light-emitting material for the OLED TV by focusing on the non-volatile feature of ILs at high vacuum·high temperature.

This technology uses a principle of separating impurities in the order of vaporizing the organic light-emitting material in a vacuum chamber; dissolving it in a liquid filter of ionic liquid; and recrystallizing supersaturated material in the liquid. It enables to get 99.95% of high purity organic light-emitting material through one refining process.

It is a completely new concept of large scale refining method based on the non-volatility characteristic of ionic liquid at high vacuum·high temperature.

The team is credited with the success of new technology development which can overcome the cons of the existing sublimation refining method including refinery yield rate, automation and continuous process of equipment, and efficiency of mass production. It is also expected to bring a huge cost reduction effect by recycling; collect and reprocess during refinery process, of the expensive but non-volatile ionic liquid.

According to “2014 OLED Emitting Material Annual Report Market Forecast (~2020)” by a professional OLED market research firm, UBI Research, the OLED emitting material market is expected to grow to 1.3 trillion won in 2017 from 2014 estimation of 543 billion won. Forecasted annual growth rate is over 30% and experts see that the growth will be much larger if large size display market including the AMOLED TV expends in full-scale.

Dr. Taewon Kim, said, “this technology increased the yield rate and decreased the production cost by more than 50%. And an ultimate goal is to reduce the current price by one tenth” and “technology development is in progress with companies.” He also said, “the success is a game changer with enormous potential to turn the OLED TV market-to-explosively grow” and “based on the low-cost and large scale refining original technology, domestic businesses will largely contribute to preoccupy the global market of forward-backward industry regarding the OLED TV.”

The team currently applied 16 cases for patent with related process․equipment technology in and out of the country and plans active technology transfer to related businesses.

140730_한국생산기술연구원

 

<Comparison of refining methods for organic light emitting materials Source: KITECH>