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Direct Bonding for In-cell, On-cell, OGS, G+G, G+F

Abbreviations

G+G: Glass + Glass

G + F: Glass + Film

OGS: One Glass Solution

OCA: Optical Clear Adhesive

LOCA: Liquid Optical Clear Adhesive

SCA: Solid Clear Adhesive

ITO: Indium Tin Oxide

LCD: Liquid Crystal Display

OLED: Organic Light-emitting Diode

EPD: Electronic Paper Display

What are G+G, G+F, In-cell, On-cell and OGS

In order to distinguish the touch function in different structures, people identify them as G+G, G+F, In-cell, On-cell and OGS. G+G is to bond the ITO sensor glass to cover glass using OCA. G+F is to bond the ITO sensor film to cover glass using OCA. The film could be one layer of film, or bonded film+film, or bonded x/y array film. Both G+G and G+F are with a separate touch layer which need to be bonded to the cover glass. In order to make the touchable display product thinner and improve the display performance, people integrate the touch layer with display panel and identify them On-cell and In-cell, or integrate the touch layer with cover glass and identify it OGS.

All these structures need to be bonded with cover glass as protection. We can bond the top layer (cover glass or bonded cover glass) with the display panel (LCD, OLED or EPD) using OCA or LOCA depending on the structure of the display panel.

What is the Difference among G+G, G+F, In-cell, On-cell and OGS Touch Products

Separate Touch Function:

Integrated Touch Function

1. 1. Transparency

OGS is the best in terms of screen transparency and visual effects, followed by In-Cell/On-Cell and G+G/G+F.

1. 2. Thickness

Generally speaking, In-Cell is the lightest and the thinnest. After OGS, On-Cell is slightly worse than the previous two, then G+G, then G+F is thickest.

1. 3. Screen Strength (impact resistance, drop resistance),

On-Cell is the best, G+F is second, then G+G, then OGS, and In-Cell is the worst.

1. 4. Touch Sensitivity

OGS has best touch sensitivity, then G+G/G+F, then On-Cell/In-Cell screens.

OGS has better touch sensitivity, but this is sometimes not a good thing. The high sensitivity of OGS is prone to "crossover". Subtle dust, sweat, and water vapor can cause "misoperation" of the touch screen. In addition, because the In-Cell screen directly fuses the touch layer with the liquid crystal layer, the sensing noise is large, and a dedicated touch chip is required to perform filtering and correction processing. The dependence of the OGS screen on the touch chip is not so high.

1. 5. Technical Requirements

In-Cell/On-Cell are more complex than OGS, and production control is more difficult. G+G and G+F are easist to control.

1. 6. Direct Bonding Difficulties

To bonding, Hard to Soft is easier than Hard to Hard. In SWI, we use rolling bonding for hard to soft (Glass to Film bonding), and laminaion bonding for hard to hard (Glass cover to ITO glass, or Glass Cover to LCD/OLED/EPD).

Why do We Need Direct Bonding for all these Laminated Layers

If we don’t fully bond the layers, there will be air gap created between 2 layers of sheet or parts. The gap results in setbacks which include a more fragile screen glass, loss of touch accuracy, and a narrower viewing angle.

Optical bonding (direct bonding) eliminates the air gap between 2 layers. This will improve the ruggedness, touch experience, durability, touch experience, and the display performance, and also maximum the dust & moisture protection.

What does SWI Provide for the Optical Bonding

SWI is making traditional touch panels (G+G), and processing optical bonding of G+G, G+F, F+F, In-cell, On-cell and OGS for LCD, OLED and EPD, using OCA, SCA and LOCA. The maximum bonding size is up to 110”.