Patent Publication Number: US-2012034452-A1

Title: Article and method for manufacturing same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is related to co-pending U.S. patent applications (Attorney Docket No. US34923, US34942, US34943), entitled “ARTICLE AND METHOD FOR MANUFACTURING SAME”, by Zhang et al. These applications have the same assignee as the present application and have been concurrently filed herewith. The above-identified applications are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The exemplary disclosure generally relates to articles and methods for manufacturing the articles. 
     2. Description of Related Art 
     Vacuum deposition is used to form a thin film or coating on housings of portable electronic devices, to improve abrasion resistance. However, typical vacuum deposition only can deposit black or gold coatings on the housing, limiting possible variations in appearance compared to other processes used, such as anodic treatment. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary embodiment of an article and method for manufacturing the article. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment. 
         FIG. 1  illustrates a cross-sectional view of an exemplary embodiment of an article. 
         FIG. 2  is a schematic view of a magnetron sputtering coating machine for manufacturing the article in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an exemplary embodiment of an article  10  manufactured, by a coating process, such as by vacuum deposition, and includes a substrate  11 , a bonding layer  13  deposited on the substrate  11 , and a color layer  15  deposited on the bonding layer  13  opposite to the substrate  11 . The article  10  may be a housing of an electronic device. The substrate  11  may be made of aluminum alloy, magnesium alloy, or stainless steel. 
     The bonding layer  13  is formed between the substrate  11  and the color layer  15  for improving the binding force between the substrate  11  and the color layer  15 . The bonding layer  13  may be made of titanium. The bonding layer  13  has a thickness ranging from about 0.05 micrometers to about 0.2 micrometers, and in this exemplary embodiment has a thickness of about 0.1 micrometers. In this exemplary embodiment, the bonding layer  13  has a color that does not affect the color of the color layer  15 , such as silver, white, or gray. 
     The color layer  15  is a titanium carbon-nitride layer. The color layer  15  has an L* value between about 36 to about 48, an a* value between about 4 to about 5, and a b* value between about 2 to about 4 in the CIE L*a*b* (CIE LAB) color space, so the color layer  15  is substantially chocolate color. The color layer  15  has a thickness ranging from about 0.5 micrometers to about 3 micrometers, and preferably has a thickness of 1 micrometers. 
     A method for manufacturing the article  10  manufactured by vacuum deposition may include at least the following steps. 
     A substrate  11  is provided. The substrate  11  may be made of aluminum alloy, magnesium alloy, or stainless steel. 
     The substrate  11  is pretreated. For example, the substrate  11  may be washed with a solution (e.g., alcohol or acetone) in an ultrasonic cleaner, to remove, e.g., grease, dirt, and/or impurities. The substrate  11  is then dried. The substrate  11  may also be cleaned using argon plasma cleaning. The substrate  11  is retained on a rotating bracket  50  in a vacuum chamber  60  of a magnetron sputtering coating machine  100 . The vacuum level of the vacuum chamber  60  is adjusted to 8.0×10−3 Pa. Pure argon is fed into the vacuum chamber  60  at a flux of about 300 Standard Cubic Centimeters per Minute (sccm) to 600 sccm from a gas inlet  90 . A bias voltage is applied to the substrate  11  in a range of −300 to −800 volts for about 5 to about 10 min. The substrate  11  may then be washed by argon plasma, to further remove any contaminants. Thus, the binding force between the substrate  11  and the color layer  15  is enhanced. 
     The bonding layer  13  is deposited on the substrate  11  by magnetron sputtering. The temperature in the vacuum chamber  60  is adjusted to be in range from 100 degrees Celsius (° C.) to 150° C., i.e., the reaction temperature is about 100° C. to about 150° C.; argon is fed into the vacuum chamber  60  at a flux from about 100 sccm to about 200 sccm from the gas inlet  90 , i.e. the reaction gas for depositing the bonding layer  13  is argon. The substrate  11  is rotated in a range from 2 revolutions per minute (rpm) to 5 rpm. A titanium target  70  in the vacuum chamber  60  is evaporated at a power from about 8 kW to about 11 kW, and a bias voltage is applied to the substrate  11  is in a range from about −100 volts to about −200 volts and with a duty cycle ranging from about 30% to about 70%, for about 5 min to about 15 min, to deposit the bonding layer  13  on the substrate  11 . 
     The color layer  15  is deposited on the bonding layer  13  by magnetron sputtering. The temperature in the vacuum chamber  60  is kept between about 100° C. to about 150° C., i.e., the reaction temperature is about 50° C. to about 180° C. Argon is continuously fed into the vacuum chamber  60  at a flux from about 100 sccm to about 200 sccm from the gas inlet  90 . Nitrogen is fed into the vacuum at a flux from about 40 sccm to 80 sccm and ethylene is fed into the vacuum at a flux from about 5 sccm to 20 sccm from the gas inlet  90 , i.e, the reaction gas for depositing the color layer  15  is ethylene and nitrogen. The substrate  11  is rotated in a range from about 2 rpm to about 5 rpm. The titanium target  70  is evaporated at a power from about 8 kW to about 11 kW. A bias voltage is applied to the substrate  11  is in a range of about −10 volts to about −250 volts and with a duty cycle ranging from about 10% to about 100%, for about 10 min to about 30 min, to deposit the color layer  15  on the bonding layer  13 . 
     The color layer  15  has an L* value between about 36 to about 48, an a* value between about 4 to about 5, and a b* value between about 2 to about 4 in the CIE L*a*b* (CIE LAB) color space, and is substantially chocolate color. 
     To form the color layer  15  in the above exemplary embodiment, the titanium target  70  is employed, and by adjusting the flux of the reaction gas, i.e., adjusting the flux of ethylene and nitrogen, to change the composition of the color layer  15 . So the color of the color layer  15  has an L* value between about 36 to about 48, an a* value between about 4 to about 5, and a b* value between about 2 to about 4 in the CIE L*a*b* (CIE LAB) color space, thereby a substantially chocolate colored article  10  is produced. 
     It is to be understood, however, that even through numerous characteristics and advantages of the exemplary disclosure have been set forth in the foregoing description, together with details of the system and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.