Optical bonding improves display readability

Optical bonding is an enhancement process for TFT displays in which a protective glass, a touch screen, or a combination of both is applied to a TFT display. Optical bonding eliminates the air gaps between the components and thus reduces the reflections of incident light by 99%. The result is optimum contrast and exceptional colour brilliance even when the TFT display is used outdoors and under intense ambient light. The readability is improved significantly without increasing the brightness or power consumption.

Distec's VacuBond technology is also a good choice for environments that require explosion protection. Free air spaces within the display itself, which lead to restrictions in protection certifications, can be avoided or eliminated by "free air exclusion" bonding. This is an alternative to the very expensive and often irreversible conventional methods such as filling the space with glass beads or injecting silicone into the gap between layers. Additionally, Vacubond technology allows for quick-turn prototyping. High-precision serial production is guaranteed by the automated process and the homogeneous silicone material. Clean room conditions ensure that no dust or dirt particles affect the result.

Distec further streamlines production through automated processes and the use of production jigs. These are durable molding tools which guarantee the correct position of the individual components during the bonding process and provide consistent quality when producing large quantities. The basis for any new combination of TFT display and glass is an exact measurement of the contact angles and the physical adhesion forces. This measurement is made with a modern instrument and software that decodes surface energy in polar and dispersion components by using special liquids. Such a measurement protocol is the basis for every new project.

Bernhard Staller, Managing Director, Distec, comments: "Processing the high performance silicone optoGel from the Japanese Taica company with a vacuum-bonding device the VacuBond technology offers enormous advantages compared to traditional bonding methods. In particular, small TFT displays with an extremely compact design in sizes from 2.4" to 7" can be bonded reliably, precisely and cost-effectively with this new vacuum process."

Distec provides the optical bonding service for every display up to a size of 24" in combination with touch screens of all technologies and/or protective glasses. In March, an identical VacuBond manufacturing cell will be installed at Distec's U.S. facility in Ronkonkoma, NY, improving risk management by redundancy.