Printing on glass

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By Jim Badders | Mar 07, 2017
A display with a printed glass solution.

GM Nameplate (GMN) produces custom printed glass solutions for a wide variety of industries. Whether you need a border to hide mounting hardware or want to include a logo or other backlit icon, GMN can support any printed glass solution from development through value-added assembly. With a growing amount of printed glass options available, there are many considerations to keep in mind that will help to ensure program success.

A variety of graphic features can be printed on the backside of the cover glass, including decorative borders, company names or logos, and symbols. Most printed glass solutions are predominantly done in black, but can incorporate multiple custom colors as well.

Indicator windows are also commonly requested for ambient light sensors, power indicators, or IR sensing. Dead-front indicator windows can be used to help disguise the port windows, making the windows less obvious to the user and hiding the component behind the window.

It is essential to understand how different ink colors are printed to be able to create a clean and polished look. Inks need to be printed thick enough to reach a sufficient level of opacity in order to prevent light from showing through the background and along the edges of the screen. As a result, light colored inks require an additional ink layer for opacity. The buildup of extra layers increases the ink’s thickness, but can also lead to processing difficulties later on if the ink becomes too thick.

When printing light colors – especially with precise color matches – the manufacturer must also consider the inherent tint or hue of the glass being utilized. Some types of glass, such as soda-lime, have a slight green tint that will alter the finished color of the ink when looking through the glass. To counteract this issue, colors have to be adjusted to account for the tint. If there are persisting color-matching difficulties, the customer may need to switch to a low iron soda-lime or borosilicate glass, which has a more water-clear/blue tint.

During the bonding or lamination of flexible sensor films or touchscreens to printed glass, micro air bubbles can form along the window border if the ink is too thick. To prevent the formation of these micro bubbles, the edges of the ink can be gradually pulled back. This creates a stair step effect so that the ink gradually increases and decreases in thickness, which helps the adhesive to flow.

To learn more about GMN’s printed glass and front panel integration capabilities, visit our front panel integration page.