Optical Bonding|KOTO Electric Co., Ltd.


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Optical Bonding

Optical Bonding

KOTO Optical Bonding Using UV-LOCA

We provide high quality optical bonding services using UV-curable Liquid Optically Clear Adhesive (LOCA) (Optical Clear Resin (UV-OCR)). The direct bonding which directly bond the cover material to the LCD to eliminate the air gap has become mainstream in optical bonding in order to enhance readability and durability of the display. With superior optical properties, UV-LOCA (UV-OCR) is suitable for the displays with uneven surfaces such as bezels because it is liquid.

The cover glass or touch panel is bonded on Liquid Crystal Module (LCM) using UV-LOCA. The gap between the bezel and liquid crystal surface of the LCM can be sealed with high viscosity UV-LOCA. Using our original dispensing system and lamination mechanism, we can prevent the inclusion of bubbles that largely affect the bonding yield without vacuum processing. As a result, we don't waste expensive LCM, etc. supplied by customers.


Effects of Optical Bonding


Optically Bonded Applications


Optically Bonded Applications


Optical Bonding Specifications

Items Achievements
LCM size 4. 3"、4. 8"、5. 7"、7. 0"、8. 4"、10. 4"、12. 1"、15. 0"
LOCA thickness (Between bezel and cover glass) Std. 0.5mm, Max. 1.0mm
Cover glass thickness 1mmt, 2mmt, 3mmt (Other size available)
Cover glass surface coating (Outsource) Anti-reflective (AR) coating, Anti-smudge coating, etc.

High Quality Optical Bonding

Failed bonding wastes expensive LCM or touch panel supplied by customers. However, our original bonding technique and strict quality control enable high yield and minimization of loss of material.

Curing under Black Masking and Other Shaded Areas

The black printed area of the front cover bonded with a touch panel blocks light, which means the UV light of the UV cure equip. cannot be transmitted through the black printed area to cure the area underneath.
However, we can provide the bonding with LOCA that is also curable in shaded area. It is effective in preventing the quality degradation due to insufficient curing of the adhesive under the black printed area.