A major problem for active-matrix organic-light-emitting-diode (AMOLED) technology has been a stubborn lack of scalability. That is, the manufacturing processes used to fabricate the OLED array itself (often called the front plane) and the array of thin-film transistors that drive the OLEDs (often called the backplane) have worked very well on relatively small substrates (up to Gen 4 processed half a substrate at a time), but could not be scaled up to work satisfactorily on large substrates. That has made it impossible for OLED to attain the economies of scale that AMLCDs have long enjoyed, so small (cell-phone-sized) AMOLEDs have remained significantly more expensive than small AMLCDs, moderately large AMOLEDs (10 to 20 inches) have been jaw-droppingly expensive, and very large AMOLEDs have been impossible to make in any reasonable way.
Now, that’s starting to change. Early this week, Samsung Electronics announced it will increase its total 2010 investment in manufacturing facilities and R&D to 26 trillion Won, its largest annual investment to date, spread over semiconductors and LCDs. The company will hire 10,000 new employees during the year. At a ground-breaking ceremony for a new semiconductor memory plant in Hwaseong, Gyeonggi Province, Samsung Electronics Chairman Kun-Hee Lee said, “Although the global economic environment and business conditions remain changeable and uncertain, if we invest aggressively in expanding facilities and in hiring then these circumstances also present Samsung an opportunity for future growth and to stimulate the economy.” That establishes Samsung’s aggressive mindset. Now, here comes the AMOLED part.
In a separate announcement, Samsung JV Samsung Mobile Display Co. (SMD) said it will invest an additional 2.5 trillion Won to develop the world’s largest AMOLED display manufacturing facility in the company’s Tangjeong Complex. SMD will build the new Gen 5.5 (1300×1500mm) AMOLED line by 2012. It will have a capacity of 70,000 panels per month. The line will be able to produce panels suitable for AMOLED-TVs.
On the same day DuPont announced it is now able to use its recently announced printable OLED materials to print a 50-inch OLED-TV in less than two minutes, using a custom-made printer from Dainippon Screen.
You may remember that the idea of fabricating OLED displays with drop-by-drop inkjet printing generated a lot of excitement a few years ago, but fizzled when it became clear how difficult it is to make a good-quality display with drop-by-drop printing. Dupont and Dainippon Ink developed an approach that exploited the common display geometry in which the R, G, and B subpixels line up in columns. That allows the red (for instance) OLED material to be sprayed in a continuous stream down the red columns. This continuous printing can be done with much greater consistency and speed than drop-by-drop, says DuPont, making the printing of OLED front planes practical.
DuPont’s current announcement says nothing about the solving the backplane scalability problem. But, in the past, DuPont’s Bill Feehery has said that their piece of the puzzle is the front plane, not the backplane.
Samsung, on the other hand, says it’s building a complete display plant, so it presumably has a solution in hand for the backplane as well as the front plane. What those manufacturing solutions actually are is something I hope to learn when I speak with Samsung.