Classification and Introduction of Display and Touch Screen Lamination Methods

Classification and Introduction of Display and Touch Screen Lamination Methods

The lamination of display screens and touch screens is mainly divided into three categories: Air Bonding, Optical Bonding (including OCA/LOCA), and 0-Lamination. In addition, there are built-in touch solutions such as On-Cell/In-Cell.
Air Bonding (Frame Bonding)

• Structure: The touch screen is only fixed around the edges with double-sided tape or frame adhesive strips, with a 3–0.5mm air gapreserved in the middle.
• Advantages:
• Lowest cost, simplest process, and high yield (over 90%).
• Easy to assemble and disassemble for maintenance.
• Disadvantages:
• The air gap causes strong reflection, low contrast, and poor outdoor visibility.
• Prone to dust and moisture ingress, with average long-term reliability.
• Typical Applications: Low-end industrial control screens, entry-level monitors, and low-cost tablets.
• Optical Bonding

The air gap is completely filled with optical adhesive, and the touch screen is seamlessly bonded to the display screen to form an integrated structure. There are two mainstream solutions:

1. OCA Lamination (Optically Clear Adhesive)

• Material: Solid optical adhesive film (thickness 100–200μm).
• Characteristics:
• High light transmittance (>90%) and stable adhesion.
• Requires die-cutting, high cost for large sizes, and prone to bubbles and yellowing.
• Applications: Mobile phones, tablets, and high-end small-to-medium-sized screens.

2. LOCA Lamination (Liquid Optically Clear Adhesive)

• Material: Liquid optically clear adhesive, which is cured by UV light after dispensing.
• Characteristics:
• Uniform adhesive layer, suitable for curved/irregular screens, and better yellowing resistance.
• Cost is about 30% lower than OCA, suitable for large and medium sizes.
• Applications: In-vehicle screens, large industrial control screens, and curved displays.

General Advantages of Optical Bonding

• No reflection, high contrast, and transparent display (integrated black effect).
• Dustproof and waterproof, high structural strength, and impact resistance.

General Disadvantages of Optical Bonding

• High cost, complex process, and low yield (75%–80%).
• Difficult to maintain; disassembly is likely to damage the screen.

1. 0-Lamination (Non-Adhesive Lamination)

• Structure: A transparent non-adhesive medium with a refractive index matching that of glass is filled between the touch screen and the display screen, which has no stickiness and eliminates the air gap.
• Advantages:
• Optical effect close to optical bonding, low reflection and good light transmittance.
• Lower cost than optical bonding, and easy to disassemble and repair.
• Disadvantages:
• No adhesive force; fixed by structure, so shock resistance and sealing are weaker than optical bonding.
• Applications: Mid-end industrial control, medical equipment, and scenarios sensitive to cost but requiring good display effect.

1. Built-in Touch Solutions (On-Cell / In-Cell)

Strictly speaking, they are not "lamination" but the touch layer is directly made inside the display screen:

• On-Cell: The touch sensor is between the polarizer and the color filter.
• In-Cell: The touch sensor is embedded inside the liquid crystal layer, making it thinner and lighter.
• Characteristics: Thinner screen, better light transmittance, and simple structure; however, the process is difficult, the cost is high, and maintenance is extremely difficult.

1. Comparison of Core Parameters

1. Selection Recommendations

• High-end Flagships (Mobile Phones/Tablets/In-Vehicle): Choose Optical Bonding (OCA/LOCA)to pursue display effect and reliability.
• Mid-end Industrial Control/Medical: Choose 0-Laminationto balance effect, cost, and maintainability.
• Low-end/Cost-Sensitive: ChooseAir Bondingto prioritize cost control.