Flat Panel Display Manufacturing

Jun Souk, Shinji Morozumi, Fang-Chen Luo, Ion Bita, Jun Souk, Shinji Morozumi, Fang-Chen Luo, Ion Bita

• Publisher: Wiley
• Year: 2018
• ISBN:
  9781119161363
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

An extensive introduction to the engineering and manufacture of current and next-generation flat panel displays

This book provides a broad overview of the manufacturing of flat panel displays, with a particular emphasis on the display systems at the forefront of the current mobile device revolution. It is structured to cover a broad spectrum of topics within the unifying theme of display systems manufacturing. An important theme of this book is treating displays as systems, which expands the scope beyond the technologies and manufacturing of traditional display panels (LCD and OLED) to also include key components for mobile device applications, such as flexible OLED, thin LCD backlights, as well as the manufacturing of display module assemblies.

Flat Panel Display Manufacturing fills an important gap in the current book literature describing the state of the art in display manufacturing for today's displays, and looks to create a reference the development of next generation displays. The editorial team brings a broad and deep perspective on flat panel display manufacturing, with a global view spanning decades of experience at leading institutions in Japan, Korea, Taiwan, and the USA, and including direct pioneering contributions to the development of displays. The book includes a total of 24 chapters contributed by experts at leading manufacturing institutions from the global FPD industry in Korea, Japan, Taiwan, Germany, Israel, and USA.

• Provides an overview of the evolution of display technologies and manufacturing
• Treats display products as systems with manifold applications, expanding the scope beyond traditional display panel manufacturing to key components for mobile devices and TV applications
• Provides a detailed overview of LCD manufacturing, including panel architectures, process flows, and module manufacturing
• Provides a detailed overview of OLED manufacturing for both mobile and TV applications, including a chapter dedicated to the young field of flexible OLED manufacturing
• Provides a detailed overview of the key unit processes and corresponding manufacturing equipment, including manufacturing test & repair of TFT array panels as well as display module inspection & repair
• Introduces key topics in display manufacturing science and engineering, including productivity & quality, factory architectures, and green manufacturing

Flat Panel Display Manufacturing will appeal to professionals and engineers in R&D departments for display-related technology development, as well as to graduates and Ph.D. students specializing in LCD/OLED/other flat panel displays.

1
Introduction

Fang‐Chen Luo¹, Jun Souk², Shinji Morozumi³, and Ion Bita⁴,

¹ AU Optronics, Taiwan

² Department of Electronic Engineering, Hanyang University, South Korea

³ Crystage Inc., Japan

⁴ Apple Inc., USA

1.1 Introduction

Flat panel displays (FPDs) have greatly changed our daily life and the way we work. Among several types of FPDs, the thin‐film transistor (TFT) liquid crystal displays (TFT‐LCDs) are presently the leading technology, with 30 years of manufacturing history. Recently, TFT‐LCDs reached over 95% market share across TVs, computer monitors, tablet PCs, and smartphones, and are still expanding into other application areas.

The tremendous progress in TFT‐LCD technology has brought us to the point where display performance, screen size, and cost far exceeded most industry leaders' expectation projected at the time of initial TFT‐LCD production, which started in the late 1980s. Owing to a sustained, enormous effort of display engineers around the world for the past three decades, the performance of TFT‐LCD has not only surpassed the original leading cathode ray tube (CRT) in most areas, but also the cost barrier, initially considered to be prohibitive for mass adoption, has been reduced significantly by rapid advances in display manufacturing technology.

In this chapter, we briefly review the history and evolution of display technologies, focusing mainly on the manufacturing technology associated with TFT‐LCD. With organic light emitting diode (OLED) displays in the form of mobile and TV becoming flexible, and growing and drawing a great deal of attention, the current status of active matrix driven OLED (AMOLED) display manufacturing technology is explored in sections 8A, 8B and 10.

1.2 Historic Review of TFT‐LCD Manufacturing Technology Progress

Counted from the early stage production of TFT‐LCD notebook panels that happened in the late 1980s, display manufacturing technologies have evolved enormously over the past three decades in order to meet the market demand for applications and different pixel technologies for notebook, desktop PC, LCD‐TV, and mobile devices. The progress did not come easily, but it was the result of continued innovations and efforts of many engineers across the industry that enabled adoption of new technologies, process simplifications, and increased automation in order to achieve such economics of scale. In this section, we review the historic evolution in TFT‐LCD manufacturing technology from notebooks to LCD‐TV application.

1.2.1 Early Stage TFT and TFT‐Based Displays

TFTs, more precisely, insulated‐gate TFTs, have been critical enablers for the development of flat panel displays. Figure 1.1 shows a schematic cross‐sectional view of the most common type of TFT device, a so‐called inverted staggered TFT. In this device, there is a gate electrode on the bottom, which is covered with an insulator, followed by the active semiconductor material and a top passivation insulator. The passivation insulator is etched back to allow fabrication of source and drain contacts to the semiconductor.

Figure 1.1 Schematic cross‐section of an inverted‐staggered a‐Si:H TFT.

P. K. Weimer at RCA reported first working TFT devices by using CdS as the semiconductor material in 1962 [1]. Various active materials have been developed in addition to CdS: CdSe, polysilicon, amorphous silicon (a‐Si), and so on. Among these, a‐Si remains presently the most widely used due to its practical advantages over other materials.

The first a‐Si TFT was reported by LeComber et al. [2] in 1979, and considered a major milestone in TFT history from a practical standpoint. The characteristics of a‐Si are well matched with the requirements of liquid crystal driving and provide uniform, reproducible film quality over large glass areas using plasma enhanced chemical deposition (PECVD).

The active matrix circuit incorporating a field‐effect‐transistor and a capacitor in every pixel element for LC display addressing, still widely used today, was first proposed by Lechner in 1971 [3]. Fisher et al. [4] reported on the design of an LC color TV panel in 1972. The first attempt for a TFT‐LC panel was reported in 1973 by the Westinghouse group led by Brody [5], which demonstrated the switching of one row of pixels in a 6 × 6‐inch 20 line‐per‐inch panel. In 1973 and 1974, the group reported on an operational TFT‐EL (electroluminescence) [6] and a TFT‐LC panel [7] respectively, all using CdSe as the semiconductor. In the early 1980s, there were active research activities working on a‐Si and high temperature polycrystalline silicon TFTs. Work on amorphous and poly silicon was in its infancy in the late 1970s and nobody had succeeded in building a commercial active matrix display using these materials. In 1983, Suzuki et al. [8] reported a small‐size LCD TV driven by a‐Si TFT and Morozumi et al. [9] reported a pocket‐size LCD TV driven by high‐temperature poly Si. The 2.1inch 240 × 240 pixel LCD‐TV introduced by Seiko Epson (Epson ET‐10) is regarded as the first commercial active matrix LCD product. It prompted the Japanese companies to intensify their efforts to build large‐screen color TFT‐LCDs. In 1989, Sera et al. reported on the low‐temperature poly Si (LTPS) process [10] by recrystallization of a‐Si film using pulsed excimer laser.

1.2.2 The 1990s: Initiation of TFT‐LCD Manufacturi...