Flat Panel Display Technology 許 進 明 Southern Taiwan University of Science and technology Department of Eletro-Optical Engineering 0

OUTLINE 1. Flat Panel Displays (FPDs) 2. Thin-Film-Transistor Liquid Crystal Display (TFT-LCD) 3. Organic Light-Emitting Diode (OLED) 4. Plasma Display Panel (PDP) 5.

Field Emission Display (FED)

6.

Electro-Phoretic Display (EPD)

1

Basic Requirements for A Flat Panel Display (1) Light Source Natural:

太陽光

閃電

動物/礦物產生的螢光或磷光

Artificial:

物質(氣液固態)之燃燒

(2) Light Control Device/Power Source

氣體的放電

固態電激發光效應

(3) Panel Substrate

Back light power source Data source

2

Flat Panel Displays Main FPD Technology 顯示器名稱

簡稱

顯示原理

主要應用

光源

備 註

Liquid Crystal Display (液晶顯示器)

LCD

利用液晶分子作為光閘以控 制光之穿透與否

Notebook, PC monitor, TV, PDA, Mobile phone, ViewCam, Digital Camera, Calculator etc.

非自 發光 源

已商 品化

Plasma Display Panel (電漿顯示器)

PDP

利用電漿產生之UV光激發 螢光體產生RGB三原色光

TV

自發 光源

已商 品化

Organic Light Emitting Display (有機電激發光顯示器)

OLED

利用電子與電洞在有激發光 分子材料內結合之能量轉換 激發有機分子發光

自發 光源

已商 品化

Field Emission Display (場發射顯示器)

FED

利用高電場產生之材料尖端 表面穿隧效應獲得電子 並 加速電子撞擊螢光體產生光

TV, PC monitor etc.

自發 光源

小量 商品 化

Electro-Phoretic Display (電泳顯示器)

EPD

利用上下面板電極所形成之 電場使其間之黑白帶電微顆 粒在電極板間泳動

E-book, Smart card, sign board etc.

非自 發光 源

已商 品化

Light Emitting Diode (發光二極體顯示器)

LED

利用化合物半導體內電子電洞對之產生與復合所發射 之能階轉換特性光

Commercial Display Board

自發 光源

已商 品化

Mobile phone, Digital Camera, ViewCam, PDA, Notebook, PC monitor, etc.

*** DLP投影顯示技術

3

Flat Panel Displays Types of Displays  Direct View: Mobile Phone 、 PC Monitor、Television、LED Board

 Projection Type: Projector、Rear-Projection TV、Movie Screen

 Head Mounted Display (HMD)： Medical Operation Glass、Virtual Display、Google Glass

4

Performances of FPDs Product Performance  Resolution : FHD (1920x1280 → 4K2K (3840x2560)

 Thickness & Weight  Power Consumption  Panel Size  Lifetime Technical Performance  View Angle (Imax/Lmin > 10 )  Response Time (ms)



 Contrast Ratio (200:1)  Gray Level

4000:1

 Luminance (nits/cm2)

 Color Saturation 5

Thin Film Transistor Liquid Crystal Display (TFT-LCD)

TFT-LCD Generation Based on Glass Size Generation

Glass Size

1 generation

< 350mm

2 generation

< 360mmx460mm

2.5 generation

< 400mmx500mm

3 generation

< 550mmx650mm

3.5 generation

< 650mmx830mm

4 generation

< 800mmx1000mm

5 generation

< 1100mmx1300mm

6 generation

< 1500mmx1800mm

7 generation

< 1800mmx2100mm

8 generation

< 2100mmx2400mm

8.5 generation

< 2250mmx2550mm

10 generation

< 2700mmx3000mm

Production

7

Liquid Crystal Materials  Material showing a liquid crystal phase (mesophase) is composed of many rod-like molecules.  Due to the anisotropic feature of liquid crystal phase, the solid does not immediately turn into an isotropic liquid at melting point Tm.

 A liquid crystal consists of (1) a rigid, skeleton component  crystal (2) a supple, string-like component  liquid.  Liquid Crystal molecules remain some degree of orientation order. Mesophase

Melting point

Cleaning point

Rigid component

Supple component

Isotropi c liquid

Crystalline solid

Tm

Tc

8

LCD Driving and Displaying Mechanism Passive Matrix LCD

Twisted Nematic (TN)

ITO LC ITO

Super-Twisted Nematic (STN)

LCD

C/F Glass Color Filter

Active Matrix LCD

Thin Film Transistor (TFT) Metal-Insulator-Metal (MIM)

ITO Common

Pixel Electrode Data Line Gate Line TFT Glass

9

Basic Structure of a TFT-LCD Cross-section of a color TFT-LCD Glass substrate Sealant

TFT

Black matrix

Polarizer film

Color filter

Anisotropic conductor film TAB

Common electrode Alignment film

Connection

Liquid crystal

Control IC

Capacitor Display electrode

Printed circuit board

Driver LSI

Polarizer Edge light

Light diffuser

Spacer

Waveguide plate

Prism sheet

Reflector

10

Category of TFT-LCD Category TFT-LCD Light Transmission: 

Transmission (Back-Light)



Reflective



Trans-reflective

Operation Mode: 

Normally White



Normally Black

Channel Materials 

-Si TFT-LCD



Poly-Si TFT-LCD



SCS TFT-LCD

n+ a-Si

Bottom Gate (inverse staggered)



Top Gate (normal staggered)

drain

Data line

ITO electrode

source

Gate Position: 

a-Si

glass gate

Gate dielectrics

11

TFT-LCD Displaying Mechanism Line At A Time Display Scheme

12

TFT-LCD Displaying Mechanism

Twisted Nematic (TN) mode 13

Full Color LCD Full Color : 1 million colors

100 x 100 x 100 = 106 colors Twisted Nematic (TN) mode

RGB white back-light

14

TFT-LCD Manufacturing LCD panel processing

TFT-LCD Manufacturing

LCD Cell processing

TFT-Array Color Filter

LCD Module processing Color filter

Module Engineering

Cell Engineering

TFT Array Panel 15

Structure of Back-Chanel-Etch TFT Data busline (Source)

BCE TFT structure Scan busline (Gate)

Storage capacitor

n+ a-Si

a-Si

drain

Data line ITO electrode

source Scan busline (Gate)

glass gate

Gate dielectrics

Storage busline

ITO display electrode

16

-Si TFT_LCD Manufacturing Processes TFT-Array Panel

Island formation

Mask2

Gate electrode line

Mask1 S/D & data line

Mask3 Gate Metal

Thin Film

Passivation

Mask4 Photoresist

Etch

ITO electrode

Mask5

17

-Si TFT_LCD Manufacturing Processes Color Filter Panel

Pigment Diffusion (color resist) Black Matrix Sputter Deposition

resist developing

Red negative resist Blue negative resist

Red color exposure Blue color exposure resist developing

Green negative resist

Green color exposure

resist developing

Inspection

18

-Si TFT_LCD Manufacturing Processes TFT Array Glass rubbing

Color Filter Polyimide as an Alignment Film

rubbing

Cell Processing  Glass Cutting  Alignment Film Rubbing Sealant applying

 Panel Sealing

Spacer applying

 LC Injection

LC vacuum injection and sealing

19

-Si TFT_LCD Manufacturing Processes Spacer Processing Traditional Bead Spacer dispenser Spacer

Post Spacer Organic polymer column formed by photolithography

source: CMO

20

-Si TFT_LCD Manufacturing Processes Liquid Crystal Injection 1.

Set the glass to a vacuum chamber.

2.

Vacuum the chamber & Glass heating

3.

Approach glass to liquid crystal tank and align the LC injection pole to de-bubbled 5. Detach the glass from liquid crystal surface. liquid crystal tank. Vent the chamber.

4.

Vacuum Chamber

N2

Venting Port

Liquid Crystal Tank

Liquid Crystal Tank

Liquid Crystal Tank

Pumping 21

-Si TFT_LCD Manufacturing Processes LC cleaning

Liquid Crystal Injection Hole Sealing UV glue sealing UV glue sealing

Pressurize

Gas Pressure

Gas Pressure

22

-Si TFT_LCD Manufacturing Processes One Drop Filling (ODF) for Glass > 6G

ESD plate UV glue sealing

CCD alignment

Pressurize (low pressure)

Vacuuming

Pressurize (atm)

23

-Si TFT_LCD Manufacturing Processes TFT-LCD LCM Engineering

Polarizer film attachment Polarizer 2 Top Glass

Bottom Glass Polarizer 1

Polarizer

Normally White Mode

24

-Si TFT_LCD Manufacturing Processes

Transmittance of TFT/ LCD Aperture Ratio 100%

50%

33%

31%

10%

5%

AR = At / A Metal lines ITO TFT

Polarizer 50% TFT Glass 92%

Polarizer 50% Display Liquid electrode Crystal Color Filter Glass 92% 70% 95%

Color Filter Film 35%

At A

25

-Si TFT_LCD Manufacturing Processes TFT-LCD LCM Engineering  Surface Mount Technology (SMT)

Anisotropic conducting film

Color Filter

 Tape Automated Bonding (TAB) Tape Carrier Packaging (TCP)  Chip on Film (COF)

PFC Control IC

Polarizer film

Printed circuit board

 Chip on Glass (COG)

TFT Array Panel

Driver LSI BLU

SMT

TAB

COG

COF 26

-Si TFT_LCD Manufacturing Processes Anisotropic Conductive Film (ACF)

TAB Bonding Processing

Conductive Particle Attach ACF to glass 接合劑 (熱固性或 熱朔性或 兩者混合

Resin

ACF ITO Glass

Metal FPC Cu electrode

Align Cu lines to ITO pads Insulating layer

Pressure & pressure

COG Processing Driver IC

Connected

apply heat and pressure

Top glass Bottom glass

Resin coating

Resin

-Si TFT_LCD Manufacturing Processes Back Light Module (BLM) Polarizer Color Filter Liquid Crystal TFT array panel Polarizer

Prism Sheet Dispersion Sheet Light Guide Sheet Reflector

Cold Cathode Fluorescent Lamp (CCFL)

BLM Light Source Cold cathode fluorescent lamp Light-Emitting Diode (LED) Light-guide sheet to guide light into central part

Reflector to direct light towards LCD surface

Prism sheet to increase the brightness Bright Enhancement Film (BEF)

Diffusion sheet Provides an uniform illumination

-Si TFT_LCD Manufacturing Processes TFT-LCD manufacturing must be conducted in a clean room environment

IC circuits can be shorted or opened by a tiny particle dropping on wafer

Yield can be dramatically dropped by tiny particles dropping on glass 29

-Si TFT_LCD Manufacturing Processes Wide Viewing Angle Technology for Large LCD-TV

MVA 廣視角技術

IPS 廣視角技術

E=0

E = Eo

TFT glass

ITO pixel electrode

ITO common electrode 30

-Si TFT_LCD Manufacturing Processes

ODF

31

-Si TFT_LCD Manufacturing Processes In-line Sputter System for ITO Film Deposition (Applied Film Corp.)

Cluster PECVD System for TFT Film Deposition (Applied Materials Corp.) 32

What is the Big Thing for TFT-LCD  System On Glass (SOG)

Development of Low Temperature Poly-Si TFT（LTPS TFT）

Sharp proposed System On Glass Concept in 1996

Speaker Antenna

Touch Display RAM CPU

interfaces ROM Product: SOG panel Year: 2002 Oct. Manufacturer: Sharp / Semiconductor Energy Lab (SEL) Microprocessor: 3MHz Design rule: 3- to 4-micron LTPS technology: continues grain silicon (CGS) 33

What Are the Next Big Things for TFT-LCD Structure of LTPS-TFT Spacer

LC

Alignment film

pad

ITO pixel electrode

P-MOS

N-MOS

Periphery IC

N-MOS

glass

TFT array 34

What is the Big Thing for TFT-LCD Low Temp. Crystallization of a-Si

 Excimer Laser Anneal (ELA) Possible area 10mmx300mm

Laser Source

UV radiation

a-Si

Surface absorption (>1400°C) /a-Si melting Nucleation and grain growth during cooling down

 Continuous Grain Silicon (CGS)  Metal-Induced-Crystallization (MIC)

Metal (Ni)

SiOx a-Si

200~550 °C thermal annealing Metal atoms diffuse into a-Si matrix to form metal silicides MSix, and the nucleation and growth of the Si grains proceed due to the injection of metal out of the metal silicided

35

Organic Light-Emitting Diode (OLED)

Introduction to OLED

Data Line

可繞式印 刷電路板

Vdd

Storage Capacitor

Scan Line

Control TFT

Switch TFT OLED

PCB

PCB

封裝蓋板 阻隔壁 OLED

OLED

OLED

封膠

金屬電極線

Driver IC

有機發光材料 非均向導電膜 Driver IC

Glass P-Si TFT

P-Si TFT

玻璃基板

ITO電極線

PCB

P-Si TFT

Full Color AMOLED

Single/Area Color PMOLED

37

OLED Light-Emitting Mechanism

Singlet transition triplet transition Fluorescence

Phosphorescence

38

OLED Manufacturing Processing Single Color PMOLED

Rib formation by photolithography

EL thermal deposition

UV封膠

Metal thermal deposition

Passivation layer deposition by PECVD

無水氧手套箱

玻璃基板 封裝蓋板

UV光照射

39

OLED Manufacturing Processing OLED : Small Molecule

Thermal Evaporation in a vacuum system

PLED : Polymer

PLED : Inject Printing in a glove box

Organic vapor phase deposition (OVPD) A high-precision inkjet printer for making polymer OLED displays

40

OLED Manufacturing Processing

41

OLED Manufacturing Processing Packaging Buffer

robot

N2 with low H2O and O2 Positive Pressure

robot

LL-out

手套箱

Atmospheric Robot



UV框膠塗佈



蓋板貼附



UV光照射

Glass cassette 42

OLED Packaging Why Packaging? Defects and Joule heat generally degrade optoelectronic characteristics of an OLED, and lead to an short lifetime. Degradation of OLED is accelerated in the presence of O2 and H2O.

H2O

O2

Getter Glass back plate UV glue

How to Protect OLED? 1. Protect OLED with a SiO2 passivation layer. 2. Seal OLED with a Glass back plate by curing of UV glue 3. Attach desiccant inside the cell. Glass back plate

Glass Box : O2/H2O < 1 p.p.m.

UV Curing 43

Plasma Panel Displays (PDP) 150”

150”

152”

Basic Structures of PDP

45

Structures of PDP AC Surface –Faced PDP

46

PDP Displaying Mechanism

47

AC type PDP Displaying Mechanism

48

AC type PDP Displaying Mechanism Address and Display Separation (ADS) Sub-frame

1 2 3 4 5 6 7

8

20 21 22 23 24 25 2 6 27 0 0 0 0 0 0 0 0 1 0 0 0 1 0 1 1 1 1 1 1 1

0 = 0 0 = 21+25 = 37 1 = 255

One Frame Sub-frame 1

Write in

Sustain

Sub-frame 2

Sub-frame 8

Erase 49

PDP Manufacturing Processing Bottom Glass

Top Glass

玻璃清洗

黑色對比層形成

金屬定址電極形成 反射層形成

玻璃清洗 ITO電極形成 金屬輔助電極形成 (Ag, Ni) 介電層披覆 (玻璃漿料) MgO保護層披覆

阻隔壁形成 (玻璃漿料)

螢光體網印 封漿塗佈 (玻璃陶磁)

50

PDP Manufacturing Processing

51

Field Emission Display (FED)

What is FED ? FED is also called flat CRT

53

Structure of FED

BM

spacer

phosphors Anode Sealant

Fowler Nordheim Eq.

Gate metal

I =  V2 exp(-3/2/V) /φ

dielectric emitter

Field Emission Cell (FEC)Field Emission Array (FEA)

cathode

54

Display Theory of FED

Display Theory of FED

Full Color FED

FED Manufacturing Cathode Panel Spindt method

Glass cleaning Cathode metal sputtering + patterning Dielectric SiOx deposition Gate metal deposition Gate metal patterning Gate metal + SiOx etch Pad layer + emitter metal glazing angle deposition (MBE) Pad layer stripping

CNT method

Glass cleaning Cathode metal sputter + pattern Catalytic metal depo. + pattern Dielectric SiOx deposition Gate metal deposition Metal + SiOx pattern & etch CNT growth (CVD)

Anode Panel Glass cleaning Anode ITO Sputtering + patterning BM deposition + patterning R, G, B phosphor screen printing + baking spacer oxide screen printing + baking

Sealant printing Hot Press Tube soldering Pump & cut

58

Electro-Phoretic Displays (EPD)

EPD Applications

Watch co-developed by Seiko Watch and Seiko Epson

EPD Display Mechanism

61

EPD E-Ink roller printing  Paper like readability

Technology of E Ink

 Ultra-low power consumption  Ultra portable

Manufacturing of E Ink

Source: E Ink/2003

62

EPD Micro-cup

Source: Sipix

63