Paper EM-ThP24
Deposition and Characterization of Hydrophobic Coatings on Electronic Devices

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

More cell phones are damaged by water than by any other means, and this damage often requires the devices to be discarded. The number of damaged phones is also increasing because these phones are now taken almost everywhere. Chemical vapor deposition may provide a solution to this problem, which is large (100.9 million Smartphones were shipped in Q4 2010). For example, the phones may be coated with a hydrophobic monolayer or multilayer of fluorosilanes. Bonding of the fluorosilane may be improved using of a primary adhesion layer, which may be a different silane monolayer, e.g., an isocyanatosilane, and/or by introduction of hydroxyl groups via plasma treatment. The latter process is typically rapid and economical and can take place both on oxide and polymeric materials. The presence of OH groups can be assayed by XPS, ToF-SIMS and ATR-FTIR. The density of surface hydroxyl groups can be varied by changing the proportions of etch gases, the time and intensity of the plasma treatment, and the system base pressure. The hydrophobicity of the surface can be characterized by contact angle goniometry and XPS and ToF-SIMS analysis of fluorine. Resistance to abrasion can be tested with a Martindale abrasion tester. This work can be further extended to touch screen panels in equipment used under water.