Protective sheath for portable electronic device and method for making same

A method for making a protective sheath for receiving a portable electronic device therein and protecting the portable electronic device from being scratched, comprising the steps of:

• (1) injection molding a plastic base;
• (2) pre-treating the base, comprising cleaning and pre-heating the base;
• and
• (3) putting the pre-treated base in a vacuum chamber for plasma chemical vapor deposition treatment;
• whereby a coating comprising silicon oxide is formed on a surface of the base.

An electronic device assembly comprising:

• a protective sheath including:
• a lower cover;
• an upper cover pivotally engaged with the lower cover and comprising a window with a transparent plastic base;
• at least one transparent coating comprising silicon oxide applied on the base;
• two side wings made of elastomer integrally formed at two opposite sides of the window, respectively;
• and
• an electronic device removeably received within a spaced defined between the upper cover and the lower cover.