What is Optically Clear Adhesive (OCA) ?

This article briefly introduces the optically clear adhesive as well as the main applications. The article focus on four questions about OCA.

1. What is Optically clear adhesive (OCA)?
The Optically clear adhesive (OCA) is bonding technology used in touch panels and display devices to bind the cover lens, plastic, or other optical materials to the main sensor unit or each other. These adhesives improve optical characteristics and durability.


Optical bonding, including LOCA and non-liquid OCA tape, are used in a wide range of electronic equipment, especially those with touch panels. The adhesive bonds the touch panel to the main liquid crystal display, and also bonds any protective cover, such as the lens, to the touch panel. After application, the adhesive is cured onto the device through UV, heat, moisture, or a combination, depending on the manufacturer and specifications. Major applications include capacitive touch panels, 3D televisions (3D TV), and glass retarders.

Optical bonding improves optical performance of displays. It eliminates the air gap between the cover glass and LCD, and usually includes an anti-reflective (A/R) coating (as well as anti-smudge and anti-glare treatments on the cover glass). Optical bonding improves the contrast ratio by reducing the amount of reflected light, thus improving viewability. This is especially important in outdoor applications, where direct sunlight can decrease viewability.

LOCA is generally used in displays and touch panel applications. Application is expected to increase as mobile devices, televisions, tablets, monitors and laptops migrate to touch interfaces. 

2.What are advantages of OCA compared to other adhesives?

Reliable bonding
Adhesion to non-even surfaces
Superior optical properties

3. How is Optically Clear Adhesive (OCA) used?

Lamination of films to rigid or flexible substrates
Lamination of two rigid substrates
Bonding of touch panels to cover lens
Bonding of displays to cover lens or touch panels
4. How is Optically Clear Adhesive (OCA) produced?

For a roll-to-roll coating, the coating machine works as following:

Unwind unit --Dust eliminator --Infeed unit --Web guide--Metering roll coater--UV drier --Web guide --Feed unit (cooling) --Web Accumulator--Outfeed unit--Rewind unit

Huayan offers a coating solution to manufacture Optically clear adhesive. To learn more about the process, click https://en.huayang-ppm.com/product/oca-film-coating-machine.html.

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