A world without a touch screen is hardly imaginable these days as the relevance of displays in our daily life is increasing. One example are the control consoles in vehicles, which in all new models are equipped with larger and more sophisticated digital displays. With the Openair-Plasma technology, Plasmatreat GmbH contributes one of the most important processes for modern display production.
“The introduction of touch screens in the automotive industry is a real boost for display manufacturers,” explains Nico Coenen, Global Business Development Manager at Plasmatreat GmbH. A new product line is set up for each new vehicle model, since different models differ considerably in terms of shape, size and functionality. For example, a curved display requires a completely different handling procedure than a flat display design. The increased use of such displays also leads to new challenges, such as the limited readability of displays under light exposure. Therefore, Plasmatreat’s Openair-Plasma process plays a crucial role in display production.
To improve the readability of vehicle displays in bright environments, optical bonding is used. Optical bonding is a process that fills the air gap between the cover glass or touch panel and the actual display e.g. LCD, OLED with an optically clear OCA adhesive matched to the refractive index to drastically reduce reflections. This method optimizes indoor and outdoor readability, produces improved display performance, and results in a significantly higher user experience.
Before applying the OCA, the glass surfaces are treated with Openair-Plasma. By cleaning the surface through the plasma application and generating highly reactive free radicals the surface properties are improved. This results in improved wetting of the OCA between the two surfaces to be bonded and increased adhesion for better resistance to rapid temperature changes.
Another process step is to assemble the bonded sub-assembly with the electronics and the front and rear side of the touch screen during final assembly. Here, too, plasma treatment enables a connection between the materials, which are typically difficult to join together. “Similar to conformal coating, the use of Openair-Plasma helps to clean and activate the surfaces so that extremely durable and resistant connections are possible between the materials,” says Coenen.
Plasmatreat is exhibiting at the upcoming productronica 2019 in hall B2, booth 103.