Patent Publication Number: US-2012027968-A1

Title: Device housing and method for making the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is one of the three related co-pending U.S. patent applications listed below. All listed applications have the same assignee. The disclosure of each of the listed applications is incorporated by reference into all the other listed applications. 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Attorney 
                   
                   
               
               
                 Docket No. 
                 Title 
                 Inventors 
               
               
                   
               
             
            
               
                 US 34428 
                 DEVICE HOUSING AND METHOD  
                 HSIN-PEI CHANG 
               
               
                   
                 FOR MAKING THE SAME 
                 et al. 
               
               
                 US 34432 
                 COATED ARTICLE AND METHOD  
                 HSIN-PEI CHANG 
               
               
                   
                 FOR MAKING THE SAME 
                 et al. 
               
               
                 US 34433 
                 COATED ARTICLE AND METHOD  
                 HSIN-PEI CHANG 
               
               
                   
                 FOR MAKING THE SAME 
                 et al. 
               
               
                   
               
            
           
         
       
     
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to device housings, particularly to a device housing having an anti-fingerprint property and a method for making the device housing. 
     2. Description of Related Art 
     Many electronic device housings are coated with anti-fingerprint film. These anti-fingerprint films are commonly painted with a paint containing organic anti-fingerprint substances. However, the print films are thick (commonly 2 μm-4 μm) and not very effective. Furthermore, the paint may not be environmentally friendly. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURE 
       Many aspects of the device housing can be better understood with reference to the following figure. The components in the figure are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the device housing. 
       The figure is a cross-section view of an exemplary embodiment of a device housing. 
     
    
    
     DETAILED DESCRIPTION 
     The figure shows a device housing  10  according to an exemplary embodiment. The device housing  10  includes a substrate  11 , and an anti-fingerprint film  13  formed on a surface of the substrate  11 . 
     The substrate  11  may be made of metal or non-metal material. The metal may be selected from a group consisting of stainless steel, aluminum, aluminum alloy, copper, copper alloy, and zinc. The non-metal material may be plastic, ceramic, glass, or polymer. 
     The anti-fingerprint film  13  is a metal-nitrogen-oxygen compound coating. The metal-nitrogen-oxygen compound may be M x O y —N or M x O y —N—Me x O y —N, wherein M, Me are two different metals and may be selected from a group consisting of titanium (Ti), aluminum (Al), silicon (Si), chromium (Cr), and zirconium (Zr), provided M is different from Me. If M or Me is one of Ti, Si, and Zr, then ‘x’ and ‘y’ may have a relationship of y≧2x; if M or Me is one of Al and Cr, then ‘x’ and ‘y’ may have a relationship of y≧1.5x. That is, M or Me of the anti-fingerprint film  13  is completely oxidized with oxygen atoms. The values of ‘x’ and ‘y’ are not restricted in this embodiment. The metal-nitrogen-oxygen compound is amorphous. The anti-fingerprint film  13  has a good anti-fingerprint property. 
     The anti-fingerprint film  13  is transparent and very glossy. The anti-fingerprint film  13  has a thickness of only about 100-500 nm. The anti-fingerprint film  13  may be formed by an environmentally friendly vacuum sputtering process, and the anti-fingerprint film  13  is tightly bonded to the substrate  11 . 
     Moreover, the nitrogen contained in the anti-fingerprint film  13  may further enhance the compactness and corrosion resistant properties of the anti-fingerprint film  13 . 
     It is to be understood that, a color coating may be set between the substrate  11  and the anti-fingerprint film  13  to make the device housing  10  more attractive. 
     A method for making the device housing  10  may include the following steps: 
     The substrate  11  is provided and to be pretreated. The pre-treating process may include the following steps: 
     The substrate  11  is cleaned in an ultrasonic cleaning device (not shown) which is filled with ethanol or acetone. 
     The substrate  11  is plasma cleaned. The substrate  11  may be positioned in a plating chamber of a vacuum sputtering equipment (not shown). The plating chamber is fixed with a target therein. The target may be made of one or two of the elements selected from a group consisting of Ti, Al, Si, and Zr. The plating chamber is then vacuum pumped to about 4.0×10 −3  Pa. Argon (Ar, having a purity of about 99.999%) may be used as a working gas and injected into the chamber at a flow rate of about 300-500 standard-state cubic centimeter per minute (sccm). The substrate  11  may be biased with negative bias voltage at a range of −300V to about −500 V, then high-frequency voltage is produced in the plating chamber and the Ar is ionized to plasma. The plasma then strikes the surface of the substrate  11  to clean the surface of the substrate  11 . Plasma cleaning the substrate  11  may take about 3-10 minutes. The plasma cleaning process enhances the bonding between the substrate  11  and the anti-fingerprint film  13 . The targets are unaffected by the pre-cleaning process. 
     The anti-fingerprint film  13  is vacuum sputtered on the pretreated substrate  11 . Vacuum sputtering of the anti-fingerprint film  13  is implemented in the plating chamber of the vacuum sputtering equipment. The inside of the plating chamber is heated to about 20-300° C. Oxygen (O 2 ) and nitrogen (N 2 ) may be used as reaction gases and injected into the chamber at a flow rate of about 300-800 sccm and 100-400 sccm respectively, and argon (Ar) may be used as a working gas and injected into the chamber at a flow rate of about 300-500 sccm. Power is now applied to the target fixed in the plating chamber, and the substrate  11  may be biased with negative bias voltage to deposit the anti-fingerprint film  13  on the substrate  11 . The negative bias voltage may be about −100 V to about −300 V. Depositing of the anti-fingerprint film  13  may take about 20-60 minutes. 
     It is to be understood that a color coating may be sputtered on the substrate  11  before sputtering the anti-fingerprint film  13 . The color coating makes the device housing  10  more attractive. 
     It is believed that the exemplary embodiment and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its advantages, the examples hereinbefore described merely being preferred or exemplary embodiment of the disclosure.