Patent Publication Number: US-2012032566-A1

Title: Housing and fabrication method thereof

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to device housings, and particularly, to a housing having a nanostructure and a fabrication method thereof. 
     2. Description of the Related Art 
     Metal and plastic, due to their water resistance, corrosion resistance and mechanical properties, are widely used in electronic devices. A common housing of an electronic device includes a metal body, an adhesive layer and a plastic portion. The adhesive layer is sandwiched between the metal body and the plastic portion, such that the plastic portion is fixed to the metal body. However, bonding strength between the metal body and the plastic portion decreases with time. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views, and all the views are schematic. 
         FIG. 1  is a cross-section of one embodiment of a housing. 
         FIG. 2  is an enlarged view of a circled portion II shown in  FIG. 1 . 
         FIG. 3  is a flowchart of a fabrication method of the housing shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , one embodiment of a housing  100  includes a main body  20  and a plastic portion  30  integrally formed with the main body  20 . The main body  20  and the plastic portion  30  can be formed in different structures. For example, the main body  20  can be a conducting sheet of a mobile phone, and the plastic portion  30  can be a battery housing of a mobile phone. 
     The main body  20  can be glass, metal, alloy, ceramic or enamel such as magnesium, aluminum, or iron. The alloy may be magnesium alloy or aluminum alloy. 
     The main body  20  includes an interface  201  contacting the plastic portion  30  and a nanostructure  203  formed in the interface  201 . The nanostructure  203  is a plurality of regular, repeating units. In the illustrated embodiment, each regular repeating unit is a sawtooth-shaped ridge. A pitch d between adjacent ridges is in the range from 10 nanometers to 500 nanometers. A height h of each ridge is in the range from 10 nanometers to 100 nanometers. A surface roughness of the nanostructure  203  is in the range from 1 nanometer to 10 nanometers. The plastic portion  30  is partially received in the nanostructure  203 , such that the plastic portion  30  is firmly formed and attached with the main body  20 . 
     In the illustrated embodiment, the nanostructure  203  is directly formed as part of the interface  201  of the main body  20 , which reduces a contact angle of water droplets to a smaller contact angle. Thus, the interface  201  of the main body  20  can remain hydrophilic for a longer time, and enhances bonding strength between the main body  20  and the plastic portion  30 . Furthermore, the nanostructure  203  is much smaller in size compared with the main body  20  as a whole, which is typically macroscopic in size. Therefore, the nanostructure  203  does not change the overall shape of the main body  20 , and does not affect the original appearance of the main body  20 . In addition, the main body  20  is connected to the plastic portion  30  without hook structures, such that the housing  100  is easily made to be more and more thinner. 
     Referring to  FIG. 3 , a fabrication method  100  of the present disclosure is illustrated as follows. 
     In step S 301 , a main body  20  is provided. An interface  201  is defined in a side surface of the main body  20 . 
     In step S 302 , the nanostructure  203  is formed in the interface  201 . In the illustrated embodiment, the nanostructure  203  is formed in the interface  201  by a laser method. 
     The laser method for the hydrophilic treatment of the nanostructure  203  includes the following steps: providing a material having a surface (step 1); providing a laser source (step 2); and applying a plurality of laser beams produced by the laser source to the interface  201  of the main body  20  to form a hydrophilic nanostructure (step 3). In step 1, the material of the main body  20  may be glass, metal, an alloy, ceramic or enamel. The particular laser source employed varies according to the material of the main body  20  provided. If the material is glass, a carbon dioxide laser is employed to process the glass surface. If the material is a metal or an alloy, a neodymium doped yttrium aluminum garnet (Nd:YAG) laser or a femtosecond laser is employed to process the metal or alloy surface. Applying the laser beams to the material surface involves well-known laser processing or laser-carving technologies. That is, high-intensity laser beams produced by the laser source are focused on the surface of the material to form a predetermined shape in the surface, all of which is controlled by a computer. The power density of the focused laser beams can be between 10 7 -10 12  watts per square centimeter, and the temperature of the surface can be up to 1×10 5  degrees Celsius. Accordingly, virtually any glass, metal or alloy material can be fused and vaporized immediately. 
     In step S 303 , the plastic portion  30  is molded on the interface  203  of the main body  20  by insert molding. The main body  20  is placed into a mold. Molten plastic material is injected on the interface  203 . After the molten plastic material is solidified, the plastic portion  30  is firmly formed in the interface  203  of the main body  20 . 
     It should be noted that the nanostructure  203  may also be a plurality of regular, repeating units having other shapes. For example, each repeating unit may be a ridge that is hump-shaped, square-shaped, step-shaped, or multi-step-shaped. The nanostructure  203  may also be defined in a portion of the interface  201 . 
     Finally, while the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.