Affiliation:
1. Product Engineering Center Visionox Technology Inc. China
Abstract
There are metal and space regions in the touch panel (TP) pattern. Their optical performance are not the same due to the difference of reflectivity. Besides, spectral response of the human eye is different to light of various wavelengths. Human have different brightness sensations for light with the same radiation power but different wavelengths, and most sensitive to the light of 555nm wavelength, which is called visual sensitivity characteristics. Thus, texture similar to touch panel pattern can be seen in specified directions. Shadowless is to eliminate or attenuate the visual differences. To achieve the desired effect, increasing the quantity of space in the metal region which can uniform the spaces distribution, adjusting the fracture mode of the space region, and adjusting the space gap are all valid ways to reduce visibility of etching pattern. Sputtering SiNx/Nb2O5 on the metal layer that is etched by hydrofluoric (HF) acid to rough the surface is also an effective method to shadowless, which can lower reflectivity on metal regions. Delta R is reduced, and pattern visible phenomenon disappears or weakens.