A patent filed by Apple in March 2014 was revealed by the United States Patent and Trademark Office on Thursday, which contains details about the company’s effort to waterproof its devices using hydrophobic coating. The patent contains “methods for shielding electronic components from moisture.”
Unlike traditional waterproofing techniques employed in existing devices, which involves sealing the entire housing of the device to prevent any water from seeping in, Apple aims to only protect the critical electrical components via a hydrophobic coating using using plasma-assisted chemical vapor deposition (PACVD) technology. This will create an insulation layer that will provide enough protection to prevent any short circuits and other damage to the electrical components when the device is exposed to liquids.
As described by Apple, the PACVD process involves charging the surface of a given substrate, in this case a device’s PCB, before placing the device in a vacuum chamber filled with a fluoropolymer gas. When a voltage is applied to the gas, it turns into plasma and ultimately settles on and adheres to the charged substrate.
The advantage of Apple’s method is that the hydrophobic coating is extremely thin and is anywhere between one to ten microns thick, which makes it ideal for smartphones, smartwatches and other devices.
To coat components that are protected by an electromagnetic interference (EMI) shield, Apple proposes to create a small opening in the shield right above the components to let the plasma in.
As for other components that might be vulnerable to corrosion and short circuits when exposed to water, Apple suggests using silicone seals to prevent such scenarios, especially on open connectors present on the PCB (Printed Circuit Board).
Looking at how advanced technologies the patent talks about, it is unlikely that we will see it come to life in a future Apple product in the foreseeable future.