TFT Screen Production Process Introduction
I. Basic Process Explanation
The TFT LCD/AMOLED production process is divided into three parts: upstream, midstream, and downstream.
- Upstream (Material Handling):
- Input Product Status: Raw materials such as glass substrates, photolithography materials, etc.
- Output Product Status: Large panel displays
- Main Processes: Photolithography (coating, exposure, development, etching), polarizer lamination, etc.
- Company’s Involvement: Not involved
- Midstream (Manufacturing):
- Input Product Status: Large panel displays
- Output Product Status: Display modules
- Main Processes: Cutting, cleaning, lamination, bonding (COG, FOG), backlight assembly, etc.
- Company’s Involvement: Actively engaged
- Downstream (Assembly and Testing):
- Input Product Status: Display modules
- Output Product Status: Finished electronic products
- Main Processes: Assembly, testing, aging, packaging, etc.
- Company’s Involvement: Not involved
II. Midstream Process Explanation
The midstream process is further divided into three segments: front-end, mid-end, and back-end.
- Front-end:
- Input Product Status: Large panel displays
- Output Product Status: Small panel displays
- Main Processes:
- Cutting: Dividing the large panel into smaller display units
- Cleaning: Removing dust and contaminants
- Lamination: Attaching polarizers and other optical films
- Debubbling: Eliminating air bubbles
- Electrical Testing: Initial testing of display functionality
- Mid-end:
- Input Product Status: Small panel displays
- Output Product Status: Display modules
- Main Processes:
- Bonding (COG, FOG, FOB): Attaching chips and flexible circuits to the display
- Conductive Particle/AOI Inspection: Checking for defects and alignment issues
- Dispensing and Drying: Applying adhesives and curing them
- Backlight Assembly and Welding: Integrating the backlight unit
- Electrical Testing and Image Inspection: Verifying display quality and performance
- Aging: Stress testing to ensure reliability
- Back-end:
- Input Product Status: Display modules
- Output Product Status: Module assemblies
- Main Processes:
- Cover Glass Loading: Attaching the protective cover glass
- TP (Touch Panel) Assembly: Integrating the touch panel with the display module
- Module Assembly Testing and Aging: Final testing and reliability checks
- Packaging and Shipping: Preparing the finished products for distribution
- Lamination Processes:
- Water Glue Lamination: Using liquid adhesive for bonding
- OCA (Optically Clear Adhesive) Glamination: Using optically clear adhesive for high-quality bonding
- Frame Glue (Box Glue) Lamination: Using frame adhesive for structural bonding
III. Detailed Explanation of Midstream Processes
- Front-end Process Details:
- Cutting: Precision cutting of the large panel into smaller displays using laser or diamond blade technology
- Baking and Drying: Stabilizing the display structure through controlled heating
- Electrical Testing: Checking for electrical connectivity and functionality
- Appearance Inspection: Visual inspection for defects such as scratches or dust particles
- Grinding and Washing: Smoothing the display surface and removing contaminants
- Polarizer Attachment: Attaching polarizing films to control light polarization
- High-Pressure Debubbling: Using high-pressure processes to remove trapped air bubbles
- Cleaning: Final cleaning to ensure a pristine surface for subsequent processes
- Mid-end Process Details:
- Automatic Loading: Automated handling of display units to ensure consistency
- COG (Chip On Glass) Bonding: Attaching driver chips directly to the glass substrate
- FOG (Flex On Glass) Bonding: Attaching flexible circuits to the glass substrate
- FOB (Flex On Board) Bonding: Connecting flexible circuits to external boards
- Conductive Particle/AOI (Automated Optical Inspection): Inspecting for proper alignment and conductivity
- Appearance and Electrical Performance Inspection: Verifying both visual and functional quality
- Dispensing: Precisely applying adhesives or conductive materials
- Drying: Curing adhesives through controlled drying processes
- Backlight Assembly and Welding: Integrating the backlight unit and securing it through welding
- Electrical Testing: Verifying the electrical performance of the assembled module
- Image Inspection: Checking for display quality issues such as color uniformity
- Aging: Subjecting the module to stress conditions to ensure long-term reliability
- Back-end Process Details:
- Cover Glass Loading: Attaching the protective cover glass to the display module
- TP (Touch Panel) Assembly: Integrating the touch panel with the display module
- Module Assembly Testing: Final functional testing of the complete module
- Aging: Additional stress testing to ensure reliability
- Packaging and Shipping: Preparing the finished products for distribution
- Lamination Processes:
- Water Glue Lamination: Using liquid adhesive for bonding, suitable for flexible applications
- OCA (Optically Clear Adhesive) Lamination: Using high-quality adhesive for optimal optical performance
- Frame Glue (Box Glue) Lamination: Using structural adhesive for robust bonding
This detailed introduction provides a comprehensive overview of the TFT screen production process, highlighting the key steps and technologies involved in each stage.
