Optical Bonding

Lucent Gel

The N2 Series of our Lucent Gel adhesive is specially formulated for laminating industrial and medical grade touch sensors and LCD panels. The N2 Series is non-conductive and can be applied to a wide variety of framed and frameless LCDs with thick or thin bezels.

Lucent Gel is a pliable silicone based solid optically clear adhesive (SOCA). Produced under strict environmental controls, Lucent Gel is transparent, UV-resistant, and can withstand a wide range of temperatures and humidity. Lucent Gel can be produced thick to fill imperfections and increase adhesion.

Lucent Gel has the following characteristics

  • Very ductile and pliable

  • Suitable for uneven surfaces

  • Fills gaps

  • Reworkable

  • High adhesion

  • Resists extreme temperatures

  • Optical characteristics not affected by environment

  • Clarity and brightness increased 10% compared to Air bonding

  • Better optical characteristics compared to liquid bonding

  • Will not yellow


The proprietary Lucent Gel bonding process and equipment minimize the generation of bubbles in the adhesive material and maximize transparency and light transmission. Currently, maximum lamination size is 27" with three different processes as follows:


Lucent Gel is first applied to touch panel then the touch panel/Lucent Gel stack is assembled with the LCD.

Reverse Lamination

There are many ways of applying Lucent Gel for optical bonding and the standard method first applies adhesive to the touch panel active area. In our proprietary reverse lamination process, Lucent Gel is first applied to the LCD to confirm gel position on the active area while avoiding the LCD frame.

Cross LCD Metal Frame Lamination

The unique properties of Lucent Gel allow it to be applied across the LCD and directly onto the LCD’s metal frame. This increases bond strength and avoids light leakage at the gel’s edge.


  • Size: 3.5” ~ 27" or entire sheet size

  • Thicknesses: 0.5 ~ 1.5 mm, and other thicknesses

  • Operation Temperature: -40°C to +80°C

  • Appearance: Colorless

  • Hardness: 14mm (51g, 1/8 inch foot, 5 seconds) under needle penetration conditions.

  • Light transmittance: 94.1% with Gorilla Glass under 25°C/400 nm conditions.

  • Refractive index: 1.40-1.41 under 20°C/589nm conditions.

  • Specific gravity: <1

  • Tensile strength at break: 1.27 N/mm based on JIS K 6815-1 standard 1.0mm thickness

  • Thermal conductivity: 0.18 W/m‧K

  • Volume resistivity: >1012 Ohm‧cm3

  • Dielectric constant: 2.93 under 50Hz(x10-4), 2.89 under 1kHz(x10-4), and 2.89 under 1MHz(x10-4).

  • Outgassing: 392.9 when extracted by pentane solvent for 16 hours and 64.9 when sample was heated at 70°C under the conditions (D3~D10)/ppm


  1. The above specifications are based on bonding material alone. The final optical bonding specifications for the entire touch panel/LCD module will depend on touch panel and LCD specifications.
  2. The above specifications are subject to change without prior notice.


When used to bond a touch panel and LCD, Lucent Gel enhances the look and performance of any product. However, the qualities of Lucent become apparent in a number of unique situations.

Extreme Climate

Lucent Gel’s superior performance in a wide temperature range allows your product to be built for extreme weather and environments.


Lucent Gel’s clarity enhances LCD brightness, increasing sunlight readability outdoors.