LCD Glass Cleaning by Atmospheric Pressure Glow Discharge Plasma

We report on a novel method for the surface modification of indium tin oxide (ITO) in LCD glass by direct exposure to a dielectric barrier discharge (DBD) at atmospheric pressure and room temperature. To remove the organic contaminants from the surfaces of ITO film in LCD glass, the atmospheric pressure RF glow discharge plasma was used. Argon (Ar) and oxygen (O2) were used as the carrier gas and reactive gas, respectively. The addition of O2 gas to Ar decreased the contact angle of water and increased the surface cleaning rate due to the increase of oxygen radicals in the plasma. The chemical characteristics of ITO surface after the plama treatment were investigated using X-ray photoelectron spectroscopy (XPS), and new carboxyl group bond was produced. The contact angle of 64° before the plasma treatment was decreased to 7° in the processing condition with oxygen flow rate of 50 sccm, treatment speed of 100mm/sec, and input power of 300W. These hydrophilic effect will be very useful in the manufacturing processes of LCD glass.