Abstract:
A method for manufacturing a casing includes steps of providing a film; attaching a strengthening plate onto the film; placing the film and the strengthening plate into a mold; and injecting a plastic material into the mold such that the plastic material and the strengthening plate are combined with each other.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a division application of Ser. No. 13/937,219, now pending, filed on Jul. 9, 2013. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a method for manufacturing a casing and, more particularly, to a casing of a portable electronic device and a method for manufacturing the same. 
         [0004]    2. Description of the Prior Art 
         [0005]    So far casings of various portable electronic devices (e.g. notebook, tablet personal computer, etc.) are manufactured by injection molding. To strengthen the casing, a strengthening member (e.g. iron member) may be placed into a mold first and then a plastic material is injected into the mold such that the plastic material and the strengthening member are combined with each other by insert molding. After the plastic material and the strengthening member are combined with each other, an outer surface always has a drop height (e.g. gap or overflowed material) such that a manufacturer must process the outer surface with additional surface treatment (e.g. spackle or grinding by abrasive paper) first and then the manufacturer can spray paint on the outer surface or process the outer surface with other appearance treatments. The aforesaid surface treatment always takes lots of labor and time such that the manufacture cost is increased. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention provides a method for manufacturing a casing and a casing of a portable electronic device so as to solve the aforesaid problems. 
         [0007]    According to an embodiment of the invention, a method for manufacturing a casing comprises steps of providing a film; attaching a strengthening plate onto the film; placing the film and the strengthening plate into a mold; and injecting a plastic material into the mold such that the plastic material and the strengthening plate are combined with each other. 
         [0008]    In this embodiment, the method of the invention may further comprise step of cutting an edge of the film. 
         [0009]    In this embodiment, the method of the invention may further comprise steps of removing the film and spraying paint on surfaces of the plastic material and the strengthening plate. 
         [0010]    According to another embodiment of the invention, a casing of a portable electronic device comprises a film, a strengthening plate and a plastic material. The film has a recess. The strengthening plate is disposed in the recess. The plastic material is disposed in the recess and combined with the strengthening plate. 
         [0011]    As mentioned in the above, the invention attaches the strengthening plate onto the film first, places the film and the strengthening plate into the mold together, and then injects the plastic material into the mold such that the plastic material and the strengthening plate are combined with each other. After insert molding, the film can prevent a drop height between an outer surface of the plastic material and the strengthening plate effectively since the film is attached on the outer surface of the plastic material and the strengthening plate. In other words, after manufacturing the casing of the portable electronic device of the invention by insert molding, the invention does not need additional surface treatment (e.g. grinding by abrasive paper). Therefore, the invention can save lots of labor and time from surface treatment so as to reduce the manufacture cost. 
         [0012]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a schematic diagram illustrating a portable electronic device according to an embodiment of the invention. 
           [0014]      FIG. 2  is a flowchart illustrating a method for manufacturing a casing according to an embodiment of the invention. 
           [0015]      FIG. 3  is a schematic diagram illustrating processes for  FIG. 1 . 
           [0016]      FIG. 4  is a top view illustrating the strengthening plate shown in  FIG. 3 . 
           [0017]      FIG. 5  is a top view illustrating a film according to another embodiment of the invention. 
           [0018]      FIG. 6  is a schematic diagram illustrating a portable electronic device according to another embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring to  FIGS. 1 to 4 ,  FIG. 1  is a schematic diagram illustrating a portable electronic device  1  according to an embodiment of the invention,  FIG. 2  is a flowchart illustrating a method for manufacturing a casing according to an embodiment of the invention,  FIG. 3  is a schematic diagram illustrating processes for  FIG. 1 , and  FIG. 4  is a top view illustrating the strengthening plate  102  shown in  FIG. 3 . The method shown in  FIG. 2  is used for manufacturing a casing  10  of the portable electronic device  1  shown in  FIG. 1 . In this embodiment, the portable electronic device  1  may be, but not limited to, a notebook. In another embodiment, the portable electronic device  1  may be a tablet personal computer or other electronic devices. 
         [0020]    In this embodiment, the casing  10  of the portable electronic device  1  is manufactured using a mold  3  by insert molding. To manufacture the casing  10  of the portable electronic device  1 , first of all, step S 10  is performed to provide a film  100  . In this embodiment, the film  100  may be made of, but not limited to, polyethylene terephthalate (PET), polycarbonate (PC) or poly(methyl methacrylate) (PMMA). Afterward, step S 12  is performed to attach a strengthening plate  102  onto the film  100 . In this embodiment, the strengthening plate  102  may be made of, but not limited to, carbon fabric or metal (e.g. iron). It should be noted that the strengthening plate  102  can be adhered onto the film  100  by an adhesive while attaching the strengthening plate  102  onto the film  100  and then the adhesive is baked so as to attach the strengthening plate  102  onto the film  100  tightly. The aforesaid adhesive may be, but not limited to, 2K adhesive containing hardening agent. 
         [0021]    Then, step S 14  is performed to place the film  100  and the strengthening plate  102  into a mold  3 . As shown in  FIG. 3 , the mold  3  comprises a male mold  30  and a female mold  32 . In this embodiment, the film  100  is attached on a surface  320  of the female mold  32  and the strengthening plate  102  faces a surface  300  of the male mold  30 . Then, a plastic material  104  is injected into the mold  3  through an inlet  302  of the male mold  30  such that the plastic material  104  and the strengthening plate  102  are combined with each other. In this embodiment, the plastic material  104  may be, but not limited to, a mixture of polyamide fiber (PA) and glass fiber (GF), a mixture of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) or a mixture of polyphenylene sulfide (PPS) and glass fiber (GF). It should be noted that a plurality of indentations  1020  may be formed on a periphery of the strengthening plate  102  (as shown in  FIG. 4 ) so as to strengthen the connection between the plastic material  104  and the strengthening plate  102 . 
         [0022]    Then, step S 16  is performed to open the mold  3  so as to take out a semi-manufactured product consisting of the film  100 , the strengthening plate  102  and the plastic material  104 . After taking the semi-manufactured product out, step S 18  may be performed to cut an edge of the film  100  so as to finish the casing  10  of the portable electronic device  1 , as shown in  FIG. 3 . On the other hand, after taking the semi-manufactured product out, step S 20  may be performed to remove the film  100  and spray paint on surfaces of the plastic material  104  and the strengthening plate  102  so as to finish the casing  10  of the portable electronic device  1 , as shown in  FIG. 3 . After insert molding, the film  100  can prevent a drop height between an outer surface of the plastic material  104  and the strengthening plate  102  effectively since the film  100  is attached on the outer surface of the plastic material  104  and the strengthening plate  102 . Accordingly, no matter whether the film  100  is removed, the surface of the casing  10  is very flat and does not need additional surface treatment (e.g. spackle or grinding by abrasive paper) . Furthermore, if the film  100  has to be removed, the strengthening plate  102  may be adhered to the film  100  by an adhesive with low stickiness. 
         [0023]    It should be noted that if the film  100  is kept on the casing  10 , the casing  10  comprises the film  100 , the strengthening plate  102  and the plastic material  104  correspondingly. As shown in  FIG. 3 , the film  100  has a recess  1000 , and the strengthening plate  102  and the plastic material  104  are disposed in the recess  1000  and combined with each other. 
         [0024]    Three embodiments in the following are used for describing related parameters set by the invention. 
       Embodiment 1 
       [0025]    The invention can take a mixture of PA and 45% GF to be the aforesaid plastic material  104 , take carbon fabric to make the aforesaid strengthening plate  102 , and take PET to make the aforesaid film  100 . In this embodiment, the temperature of the plastic material  104  may be between 310° C. and 330° C., the temperature of the male mold  30  and the female mold  32  may be about 130° C., the speed for injecting the plastic material  104  may be between 30% and 40%, and the temperature and time for baking the strengthening plate  102  and the film  100  may be about 60° C. and 30 minutes, respectively. 
       Embodiment 2 
       [0026]    The invention can take a mixture of PC and ABS to be the aforesaid plastic material  104 , take carbon fabric to make the aforesaid strengthening plate  102 , and take PET to make the aforesaid film  100 . In this embodiment, the temperature of the plastic material  104  may be between 250° C. and 260° C., the temperature of the male mold  30  and the female mold  32  may be about 70° C., the speed for injecting the plastic material  104  may be between 30% and 40%, and the temperature and time for baking the strengthening plate  102  and the film  100  may be about 60° C. and 30 minutes, respectively. 
       Embodiment 3 
       [0027]    The invention can take a mixture of PPS and 45% GF to be the aforesaid plastic material  104 , take carbon fabric to make the aforesaid strengthening plate  102 , and take PET to make the aforesaid film  100 . In this embodiment, the temperature of the plastic material  104  may be between 310° C. and 330° C., the temperature of the male mold  30  and the female mold  32  may be about 130° C., the speed for injecting the plastic material  104  may be between 30% and 40%, and the temperature and time for baking the strengthening plate  102  and the film  100  may be about 60° C. and 30 minutes, respectively. 
         [0028]    It should be noted that the material of the film  100  can be selected according to the plastic material  104 . For example, a film capable of resisting high temperature is selected for a high temperature plastic material and a film capable of resisting low temperature is selected for a low temperature plastic material. Furthermore, the parameters adapted for insert molding can be set according to the material of the film  100 , the material of the strengthening plate  102  and the plastic material  104 . 
         [0029]    Referring to  FIGS. 5 and 6 ,  FIG. 5  is a top view illustrating a film  100 ′ according to another embodiment of the invention, and  FIG. 6  is a schematic diagram illustrating a portable electronic device  1 ′ according to another embodiment of the invention. As shown in  FIGS. 5 and 6 , the invention can form a pattern  1002  on a film  100 ′ in advance such that the pattern  1002  will be formed on a casing  10 ′ after the plastic material  104  and the strengthening plate  102  are combined with each other. Accordingly, the invention can enhance visual effect of the appearance of the casing  10 ′ of the portable electronic device  1 ′. In this embodiment, the pattern  1002  may be formed on the film  100 ′ by, but not limited to, ink printing, coating or the like. 
         [0030]    As mentioned in the above, the invention attaches the strengthening plate onto the film first, places the film and the strengthening plate into the mold together, and then injects the plastic material into the mold such that the plastic material and the strengthening plate are combined with each other. After insert molding, the film can prevent a drop height from being formed on an outer surface of the plastic material and the strengthening plate effectively since the film is attached on the outer surface of the plastic material and the strengthening plate. In other words, after manufacturing the casing of the portable electronic device of the invention by insert molding, the invention can spray paint on the surface of the casing or process the surface of the casing with other appearance treatments directly without additional surface treatment (e.g. spackle or grinding by abrasive paper). Therefore, the invention can save lots of labor and time from surface treatment so as to reduce the manufacture cost. 
         [0031]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.