Samsung TFT-LCD Module Main Failure mode AMLCD Division Samsung Electronics Co., Ltd

Contents 1. Main Failure Mode 2. Main Failure Mode (detail)‏ Samsung (AMLCD) Responsibility ※ Reference Customer Responsibility

1. Main Failure in TFT-LCD Failure Mode in TFT-LCD 1) Pixel (Dot) Defect Defect perceived by the eyes of viewer on a pixel unit basis due to defect in pixel area such as TFT elements, pixel electrodes, and color filter, etc. 2) Line Defect Defect on a line unit basis due to Open/Short between bus line inside panel or with common electrodes as well as driver IC lead open.

1. Main Failure in TFT-LCD Failure Mode in TFT-LCD 3) Electrical (Driving) Defect It includes functional defect of circuit components operating TFT-LCD, abnormal signal in C-PBA, defect arising from fault of Gate or Data driver IC. 4) Polarizer Defect Scratch line or Sink mark or Bubble (air trapped) on/under the polarizer. (Refer to spec for limit of acceptance)‏

1. Main Failure in TFT-LCD Failure Mode in TFT-LCD 5) Uniformity Defect on uniformity imbalance basis due to Cell gap variation or Imbalance of C/F depo. or Particle in LC or Missalign the panel, etc. 6) B/L Defect Defect perceived by scratched on the B/L sheet or folded sheet. Or particle is inside a B/L unit. (Refer to spec for limit of acceptance)‏

1. Main Failure in TFT-LCD Failure Mode in TFT-LCD 7) Hard Defect Glass damaged by external force or internal particle 8) Appearance Defect which can be observed under no display condition such as abnormal appearance, appearance damage, components breakage, labels or assemblies not attached or wrong attached, etc. damaging quality of product regardless of the quality of screen display.

1) Pixel (Dot) Defect 1-2. Dot distance over : Dot defect distance is not acceptable. (Refer to spec for limit of acceptance)‏ 1-1. Dot over : Bright or Dark color dot on the screen. (Refer to spec for limit of acceptance)‏ 2. Main failure in TFT-LCD (detail)‏ Bright DotDot shining brightly on dark screen. (Pixel)‏ Failure modeDescription Dark DotDark dot appearing on bright screen. (Pixel)‏ Classification by Phenomenon AdjacentMultiple dot defects connected. Failure ModeDescription DistanceMultiple dot defects distributed inside specified area. Classification by Form [Bright Dot] [Dark Dot] [Adjacent] [Distance]

1) Pixel (Dot) Defect – pixel structure 1-3. One pixel (LTA320, 400, 460W2 Model)‏ 2. Main failure in TFT-LCD (detail)‏ It’s ½ Pixel (Not 1 Pixel!)‏ Please, do not confuse this pixel type One pixel (LTA320, 400WT Model)‏ [320WT][400WT] It’s 1 Pixel! 1 Pixel

2) Line Defect 2-2. Gate line Defect : One or two adjacent Horizontal line defect 2. Main failure in TFT-LCD (detail)‏ 2-1. Data line defect : One or two adjacent Vertical line defect 2-3. D/C Short : Common line & Data line Short

2) Line Defect 2-5. G/D Short : Gate line & Data line short 2. Main failure in TFT-LCD (detail)‏ 2-4. G/C Short : Gate line & Common line short

3) Electrical (Driving) Defect 3-2. No display : Only bright (TN Mode) or dark (PVA Mode) screen is observed. No color images 2. Main failure in TFT-LCD (detail)‏ 3-1. A/D : Display is unstable. Show distorted images [PVA Mode] [TN Mode] 3-3. Crosstalk : Shadow or gray effect appears vertically/horizontally from the image. Horizontal Vertical

3) Electrical (Driving) Defect 3-5. Noise : Some interference lines across the screen. 2. Main failure in TFT-LCD (detail)‏ 3-4. Flicker : Image unstable and display “vibration effect”. Can be detected using windows shut down pattern. Cyan 2X1 or 1X1 Green 2X1 or 1X Gray fail : Some gray scales doesn’t display properly.

4) Polarizer Defect 4-2. Dent : Sink mark on the polarizer surface. (Refer to spec for limit of acceptance)‏ 2. Main failure in TFT-LCD (detail)‏ 4-1. Scratch : Scratch line on the polarizer surface. (Refer to spec for limit of acceptance) 4-3. Bubble : Bubble (air trapped) under the polarizer surface. (Refer to spec for limit of acceptance)‏

5) Uniformity 5-2. Gap (Black / White)‏ : Defect on uniformity imbalance basis due to Cell gap variation 2. Main failure in TFT-LCD (detail)‏ 5-1. Horizontal/Vertical Mura : horizontal/vertical dark/bright area appeared at mid-gray scale 5-3. Spot : Small or large size of circular shape mura Horizontal Vertical Black gap White gap Black spotWhite spot

5-5. Arc mura 2. Main failure in TFT-LCD (detail)‏ 5-4. Seal gap (Edge gap)‏ : Edge point looks yellowish(White) or dark(Mid-gray)‏ by excessive dispense of sealant 5-6. C/F Mura : Stains in R/G/B C/F. Mura can be detected R/G/B Pattern Horizontal Vertical 5) Uniformity

6) B/L Defect 6-2. Sheet wrinkle : Folded sheet cause wave effect on back light unit 2. Main failure in TFT-LCD (detail)‏ 6-1. B/L particle : Some point looks dark in white pattern by foreign material inside the backlight unit (Refer to spec for limit of acceptance)‏ 6-3. No(Dim) video : Dim display of image, due to spoilt B/L which cause no light source.

7) Hard Defect 7-1. Crack : Glass was cracked progressively 2. Main failure in TFT-LCD (detail)‏ 7-2. Broken : Glass was perfectly broken by external force

8) Apperance 8-2. Screw : Check the not-inserted & incompletely-inserted 2. Main failure in TFT-LCD (detail)‏ 8-1. Label : It have some check point 8-3. Connector : Check the crack or broken LVDS & Power Conn. (Wire)‏ Pb Free Mark Model No. Rev No. Panel ID Week Code

8) Apperance 8-5. Hole : Check the availability of inserting screw 2. Main failure in TFT-LCD (detail)‏ 8-4. Chassis damage : Chassis bent, Gap between chassis and panel