Optical bonding

Optical Bonding Competence

Optical bonding enables the connection of the touch sensor, cover glass and display to one unit using different bonding technologies.

SCHURTER has continuously developed its bonding capabilities in-house and expanded it with a wide range of investments regarding pretreatment and glass cleaning as well as in the bonding process.

Benefit from the various bonding technologies and our know-how in order to get the best solution for your customized application.

White Paper Bonding Technologies

Benefits of Optical Bonding

Better Readability

• Optical Bonding eliminates the reflections between display and

touchscreen / front glass. The refraction of light is reduced,

thus increasing the contrast and the optical brilliance.

No condensation

• By eliminating the air gap between the components no moisture

can penetrate.

No dust and dirt particles

• By eliminating the air gap no dust and dirt particles can penetrate.

Increased robustness

• A touch panel with Optical Bonding has an increased stability

and resistance to mechanical effects such as pressure, impact or

vibration. This way of installation significantly reduces the risk of

glass splintering or breakage.

Improved heat dissipation

• By filling the insulating air gap between the components, heat can

be derived to the outside.

Improved sensitivity

• The eliminated air gap between touch and glass has a positive

impact on touch detection and functionality, and the controller

does not need to constantly recalibrate due to the static connection

created.

Bonding Possibilities for touchscreens

Sensor Bonding

Optical Clear Adhesive (OCA) Lamination

This is a lamination process with optically clear adhesive (OCA). A lamination from "soft to hard" takes place, e.g. a film-based sensor (ITO / mesh) behind the coverlense. With the help of storage in an autoclave, the air bubbles are eliminated.
Liquid Bonding

Here bonding of "hard to hard" is done, i.g. a glass-based PCAP sensor is bonded behind the front glass.

Display Bonding

Air Gap Bonding

In this process, the display is glued all around with an adhesive frame directly behind the sensor or on the printing of the coverlense in the clean room. An air gap between the display and the sensor / coverlense remains.

Air bonding is a simple and cost-effective way to connect displays with coverlenses or touch sensores. Depending on the application, the assembly takes place with single adhesive strips or with a closed adhesive frame.
Liquid Optical Clear Adhesive (LOCA) Bonding

The air gap between the display surface and the rearside of the sensor is filled with a UV liquid adhesive. The adhesive is silicone-free, non-aging and UV stable. The method is suitable for TFT displays with frames.

This method is already a common bonding technology. The liquid adhesive is applied over the cover glass and then bonded to the touch panel or TFT panel. The adhesive is spread evenly and bubble-free between the two components. The adhesive is cured without heat using UV light. This prevents ...
Dry Bonding

In the dry bonding process, the bonding material is cut to the size of the visible display surface. The assembly of the front glass with the touch and display is carried out under vacuum in the bonding machine. This method is not suitable for all displays.