Method of forming anodic titanium oxide layers having dual-color appearance and article having the same

Abstract

A method of forming anodic titanium oxide layers having dual-color appearance includes the following steps: providing a cleaned substrate; depositing a titanium film on the substrate; forming a mask of a desired pattern covering a portion of the substrate; carrying out a first anodization by immersing the substrate in an electrolytic solution as anode; applying a first direct-current voltage to produce a first titanium oxide layer; removing the mask; carrying out a second anodization by immersing the substrate in the electrolytic solution as anode; applying a second direct-current voltage having a value smaller than that of the first voltage to produce a second titanium oxide layer; and cleaning the coated substrate. The instant disclosure also includes an article made by the above method.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The instant disclosure relates to a method of forming anodic titanium oxide layers having dual-color appearance and an article having the same; more particularly, to a method of forming titanium oxide layers on a substrate, such that the substrate would have at least two different color finishes, and an article having the same.[0003]2. Description of Related Art[0004]Portable electronic devices are very popular today, such as mobile phones, personal digital assistants (PDAs), laptops, etc. As the consumers begin to put more focus on the cosmetic appearances of these portable electronics, the housings of most portable electronics have shiny finishes for attractiveness. Especially for metal surfaces, which typically are specially processed to attain smoothness and shininess for visual attractiveness.[0005]To apply color on surfaces of a housing, the existing technique involves anodizing to form a thin layer of titanium ox...

AI Technical Summary

Benefits of technology

The patent describes a method to color-coat metal housings without causing surface damage or dust contamination. The method involves anodizing the metal surface with a high-voltage direct current to create a layer with a first color, and then anodizing it again with a low-voltage direct current to create a layer with a second color. This process allows for easy and accurate color-formation control, and can be repeated for different colors. The method is efficient and suitable for mass production.

Problems solved by technology

However, coloration done by such technique restricts the metal surfaces to a mono-colored state, unable to generate multi-color variations.

However, in practice, the process of forming multiple titanium oxide layers on a same housing to create different colorations thereon is quite challenging.

However, since the adhesive film covers the metal housing, the user is unable to sense the actual metallic color and touch feel.

Therefore, the challenge of producing at least two different colors on a metallic housing while maintaining the metallic touch feel is a main issue the manufacturers intend to resolve.

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