Abstract:
There is provided a case structure having a conductive pattern and a method of manufacturing the same. A case structure having a conductive pattern according to an aspect of the invention includes a case having at least one via hole formed therein; at least conductive pattern formed on an outer surface of the case; and a conductive via formed within the via hole and electrically connecting the at least one conductive pattern to a board inside the case.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of Korean Patent Application No. 2007-0084429 filed on Aug. 22, 2007, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to case structures and a method of manufacturing the same, and more particularly, to a case structure having a conductive pattern formed at a surface thereof that can be electrically connected to a board inside the case, and a method of manufacturing the same. 
     2. Description of the Related Art 
     Recently, mobile communication terminals, such as a GPS, a PDA, a cellular phone, and a wireless laptop computer, have put into widespread use. Correspondingly, there is a need for small, lightweight, and thin mobile communication terminals. In order to satisfy the need, efforts have been made to reduce the volume of the mobile communication terminal with various functions. In particular, an antenna, which is one of the most important elements of the mobile communication terminal, needs to be reduced in size. 
     In general, among antennas of mobile communication terminals, external antennas, such as a rod antenna and a helical antenna, protrude from the outside of the mobile terminal by a predetermined distance, which prevents a reduction in size and portability of the mobile terminal. Further, when the mobile communication terminal drops, the external antenna may be damaged. 
     On the other hand, internal antennas, such as a surface mounted chip antenna, which are mounted on the inside of the mobile communication terminals, may be less damaged. However, a physical size of the internal antenna makes it difficult to reduce the size of the mobile communication terminal. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a case structure having a conductive pattern, a method of manufacturing the same, and a method of forming the conductive pattern on the case. 
     According to an aspect of the present invention, there is provided a case structure having a conductive pattern, the case structure including: a case having at least one via hole formed therein; at least conductive pattern formed on an outer surface of the case; and a conductive via formed within the via hole and electrically connecting the at least one conductive pattern to a board inside the case. 
     A portion of the outer surface of the case where the conductive pattern is formed, and a wall surface of the via hole where the conductive via may be formed may be formed of a platable material. 
     The case may include a protrusion protruding toward the board mounted on the inside of the case, and the via hole may be formed in the protrusion. 
     The at least one conductive pattern may include an antenna pattern. 
     The conductive via may have one end exposed to the inner surface of the case. 
     The conductive via and the conductive pattern electrically connected to each other may be formed integrally with each other. 
     According to another aspect of the present invention, there is provided a method of manufacturing a case structure having a conductive pattern, the method including: forming a case having at least one via hole formed therein; forming a conductive via within the at least one via hole; and forming at least one conductive pattern on an outer surface of the case so that the conductive pattern is connected to the conductive via. 
     The forming a case may include: performing injection molding to form a first region that is a portion of the case by using a non-platable material; and performing injection molding to form a second region at a portion of the first region by a platable material. 
     A portion of the outer surface of the case where the conductive pattern is be formed, and a wall surface of the via hole where the conductive via is formed may be injection-molded by using the platable material. 
     The forming a conductive via and the forming at least one conductive pattern may include plating the second region. 
     The forming a conductive via and the forming at least one conductive pattern may be performed at the same time. 
     The forming a conductive via may include plating the wall surface of the via hole. 
     The forming at least one conductive pattern may include: forming a plating film on the outer surface of the case; and removing a portion of the plating film. 
     The forming a plating film on the outer surface of the case may be performed at the same time as the forming a conductive via, and the forming a conductive via may include plating the wall surface of the via hole. 
     The removing a portion of the plating film may be performed by a cutting process or an etching process. 
     According to still another aspect of the present invention, there is provided a method of forming a case structure having a conductive pattern, the method including: forming a case; forming a plating film on at least one surface of the case; and removing a portion of the plating film to form at least one conductive pattern. 
     The at least one conductive pattern may include an antenna pattern. 
     The removing a portion of the plating film may be performed by using a cutting process or an etching process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1A  is a cross-sectional view illustrating a case structure having a conductive pattern according to an exemplary embodiment of the present invention; 
         FIG. 1B  is a perspective view illustrating the case structure having a conductive pattern according to the exemplary embodiment of the present invention; 
         FIGS. 2A to 2C  are cross-sectional views of the process flow illustrating a method of manufacturing a case structure having a conductive pattern according to another exemplary embodiment of the present invention; 
         FIG. 3A to 3C  are cross-sectional views of the process flow illustrating a method of manufacturing a case structure having a conductive pattern according to still another exemplary embodiment of the present invention; 
         FIG. 4A to 4C  are cross-sectional views of the process flow illustrating a method of manufacturing a case structure having a conductive pattern according to yet another exemplary embodiment of the present invention; and 
         FIGS. 5A to 5C  are cross-sectional views of the process flow illustrating a method of manufacturing a case structure having a conductive pattern according to another exemplary embodiment of the present invention; 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
       FIG. 1A  is a cross-sectional view illustrating a case structure having a conductive pattern according to an exemplary embodiment of the present invention.  FIG. 1B  is a perspective view illustrating the case structure having a conductive pattern according to the exemplary embodiment of the present invention. 
     Referring to  FIGS. 1A and 1B , a case structure according to the embodiment of the invention may include a case  11 , conductive vias  12  and  17 , and conductive patterns  13  and  18 . 
     The case  11  may be a case of a mobile communication terminal. In this embodiment, one side of the case of the mobile communication terminal is only shown. 
     One or more via holes that pass through the inside and outside of the case  11  may be formed in the case  11 . Conductive vias are formed within the via holes to electrically connect the conductive patterns  13  and  18  formed on an outer surface of the case  11  to a board  15  that is mounted on the inside of the case  11 . 
     In this embodiment, a protrusion  11   c  is formed on an inner surface of the case  11 , and the protrusion  11   c  protrudes toward the board  15  that is mounted on the inside of the case  11 . The via hole may be formed in the protrusion  11   c . The protrusion  11   c  has a predetermined length corresponding to space between the inner surface of the case and the board mounted on the inside of the case, such that the protrusion  11   c  facilitates electrical connection between the conductive via formed in the case and the board. 
     In this embodiment, the case  11  may include a non-platable region  11   a  and a platable region  11   b . The platable region  11   b  may be formed at a portion of the outer surface of the case and a wall surface of the via hole. Therefore, the conductive patterns  13  and  18  and the conductive vias  12  and  17  can be formed on the platable region  11   b . The case  11  divided into the platable region  11   a  and the non-platable region  11   b  can be formed by dual injection molding. 
     At least one conductive pattern may be formed on the outer surface of the case  11 . The conductive patterns  13  and  18  may be antenna patterns, ground patterns, or electromagnetic interference shielding patterns. 
     In this embodiment, two conductive patterns  13  and  18  are formed. One conductive pattern  13  may be an electromagnetic interference shielding pattern, and the other conductive pattern  18  may be an inverted F antenna pattern. 
     The method of forming the conductive patterns on the outer surface of the case may be variously implemented. A conductor film having a desired conductive pattern is attached to the outer surface of the case, or the outer surface of the case is directly plated, thereby forming the conductive patterns. The conductive patterns formed on the outer surface of the case can be electrically connected to the board mounted on the inside of the case by the conductive vias  12  and  17  formed within the via holes of the case. 
     At least one via hole that passes through the inner and outer surfaces of the case  11  may be formed in the case  11 . The conductive vias  12  and  17  may be formed within the via holes. The conductive vias  12  and  17  can provide electrical connection between the board  15  mounted on the inside of the inside of the case  11  and the conductive patterns  13  and  18  formed on the outside of the case  11 . 
     The conductive vias  12  and  17  may be formed by plating the wall surfaces of the via holes of the case. Here, one set of ends of the conductive vias  12  and  17  may contact the conductive patterns  13  and  18  formed on the outer surface of the case, respectively, and other sets of ends  12   b  and  17   b  thereof may be exposed to the inner surface of the case and thus contact electrodes  15   a  and  15   b  of the board, respectively. 
     When forming the conductive patterns and the conductive vias, if a plating method is used, the conductive patterns may be integrally formed with the conductive vias connected to the conductive patterns. That is, when forming the case, a dual injection molding process may be performed so that the wall surfaces of the via holes and a region where the conductive patterns will be formed are formed by using a platable material. When the case manufactured using the dual injection molding process is immersed in a plating solution, the platable region is only plated with the material. That is, the partial region of the outer surface of the case and the wall surfaces of the via holes are only plated. Therefore, the conductive patterns formed on the outer surface of the case can be integrally formed with the conductive vias. In this way, when the conductive patterns and the conductive vias are integrally formed with each other, loose contact between the conductive patterns and the conductive vias can be prevented. 
       FIGS. 2A to 2C  are cross-sectional views illustrating the process flow for manufacturing a case structure having a conductive pattern according to an exemplary embodiment of the present invention. 
     In  FIG. 2A , a case  21  is manufactured. 
     At least one via hole that passes through an inner surface and an outer surface of the case  21  may be formed in the case  21 . A conductive via is formed within the via hole to electrically connect a conductive pattern formed on the outer surface of the case to a board inside the case  21 . 
     In this embodiment, a protrusion  21   c  that protrudes toward the board to be mounted on the inside of the case is formed on the inner surface of the case. The via hole may be formed in the protrusion  21   c . The protrusion  21   c  has a predetermined length corresponding to space between the inner surface of the case and the board mounted to the case to thereby facilitate electrical connection between the conductive via formed in the case  21  and the board. 
     The case  21  may be formed by an injection molding process. In this embodiment, the case may be injection-molded by using a platable material. 
     In  FIG. 2B , a conductive via  22  is formed within the via hole of the case  21 . 
     A portion  22   a  of the conductive via  22  is formed along a wall surface of the via hole. Both ends  22   b  and  22   c  of the conductive via may be exposed to the inner and outer surfaces of the case, respectively. One end  22   c  that is exposed to the outer surface of the case may contact the conductive pattern formed on the outer surface of the case. The other end  22   b  exposed to the inner surface of the case may contact an electrode of the board mounted on the inside of the case. 
     The process of forming the conductive via  22  may be performed by a plating process. The wall surface of the via hole of the case may be plated with a conductive material according to the plating process to form both ends of the conductive via. 
     In  FIG. 2C , a conductive pattern  23  is formed on the outer surface of the case  21 . 
     The conductive pattern  23  may be an antenna pattern, a ground pattern, or an electromagnetic interference shielding pattern. 
     A method of forming the conductive pattern  23  may be variously implemented. That is, the conductive pattern is formed by attaching a film conductive pattern to the outer surface of the case  21  so that the film conductive pattern may contact the conductive via  22 . 
     Further, the conductive pattern may be formed by plating. When the conductive pattern  23  is formed by plating, the plating process is performed at the same time when the conductive via  22  is formed, so that the conductive via  22  and the conductive pattern  23  can be formed integrally with each other. As such, when the conductive via and the conductive pattern are formed integrally with each other, loose contact between the conductive pattern and the conductive via can be prevented to thereby increase product reliability. 
       FIGS. 3A to 3C  are cross-sectional views of the process flow illustrating a method of manufacturing a case structure having a conductive pattern according to another exemplary embodiment of the present invention. 
     In this embodiment, a case  31  can be formed by dual injection molding. In  FIG. 3A , a first region  31   a  that is part of the case may be formed by using a non-platable material. Here, the part of the case may be formed while leaving space for a conductive pattern  33  to be formed on the case and a region to contact a conductive via  32 . 
     As shown in  FIG. 3B , a second region  31   b  may be formed on the space left in the first region  31   a  of the case by using a platable material. That is, injection molding may be performed by using the platable material to form the second region  31   b  according to the shape of the conductive pattern to be formed on an outer surface of the case, and a wall surface of the via hole. 
     In  FIG. 3C , the conductive pattern and the conductive via hole are formed on the case. 
     The surface of the case  31  that is formed by dual injection molding is divided into a platable region  31   b  and a non-platable region  31   a . By immersing the case  31  in a plating solution, the conductive pattern  33  and the conductive via  32  can be formed on the platable region  31   b.    
     In this embodiment, since the conductive pattern  33  and the conductive via  32  may be formed by the same plating process, the conductive pattern  33  and the conductive via  32  may be formed integrally with each other. As such, since the conductive pattern  33  and the conductive via  32  are formed integrally with each other, loose contact therebetween can be prevented to thereby increase product reliability. 
     The number of conductive patterns and the shape thereof may be varied. When a plurality of antenna patterns are formed, a multi-band antenna that can operate according to signals having different frequency bands can be easily implemented. 
       FIGS. 4A to 4C  are cross-sectional views of the process flow illustrating a method of manufacturing a case structure having a conductive pattern according to still another embodiment of the present invention. 
     In  FIG. 4A , a case  41  is manufactured. At least one via hole that passes through inner and outer surfaces of the case  41  may be formed in the case  41 . A conductive via is formed within the via hole to provide electrical connection between a conductive pattern formed on the outer surface of the case and a board inside the case. 
     In this embodiment, a projection  41   c  that protrudes toward the board mounted on the inside of the case is formed on the inner surface of the case. The via hole may be formed in the projection  41   c . The projection  41   c  has a length corresponding to space between the inner surface of the case and the board mounted on the inside of the case, such that the projection  41   c  facilitates electrical connection between the conductive via formed on the case  41  and the board. 
     In  FIG. 4B , plating is performed on the via hole and the entire outer surface. 
     When plating is performed on the via hole of the case, a conductive via  42  is formed. The outer surface of the case may be plated to form the conductive film  43   a , which then may be processed into a conductive pattern according to the following process. 
     When the via hole and the outer surface of the case  41  are plated, the via hole and the outer surface may be plated at the same time by the same plating process. Alternatively, the via hole and the outer surface may be plated according to different plating processes. 
     In this embodiment, the via hole and the outer surface of the case  41  may be plated by the same plating process. When the conductive via  42  and the conductive film  43   a  are formed by the same plating process like this embodiment, the conductive pattern to be formed by processing the conductive film  43   a  and the conductive via  42  can be formed integrally with each other, thereby preventing loose contact and increasing product reliability. 
     In this embodiment, one end  42   b  of the conductive via may be exposed to the inner surface of the case. As such, by exposing one end of the conductive via to the inner surface of the case, contact between a board mounted on the inside of the case and the conductive via can be improved. 
     In  FIG. 4C , a conductive pattern  43  is formed by partially removing the conductive film  43   a  formed on the outer surface of the case. 
     In  FIG. 4C , a potion of the conductive film  43   a  formed on the outer surface of the case is removed to form the conductive pattern  43  having a desired pattern. In this embodiment, one conductive pattern is only formed. However, when a plurality of via holes are formed in the case, a plurality of vias or a plurality of conductive patterns may be formed. When a plurality of conductive patterns are formed, the conductive patterns may be antenna patterns, ground patterns, or electromagnetic interference shielding patterns. Further, when a plurality of antenna patterns having different patterns are formed on the outer surface of the case according to this process, a multi-band antenna that can operate according to signals having different frequency bands can be easily implemented. 
     A process of processing the conductive film to form the conductive pattern can be variously implemented. 
     That is, the portion of the conductive film  43   a  can be removed by cutting the conductive film  43   a . The conductive film  43   a  may be cut by using a laser. 
     Further, an etching process may be performed on the conductive film  43   a . That is, a photo resist film having a desired conductive pattern shape may be formed on the conductive film  43   a , parts of the conductive film where the photo resist is not formed may be etched by using an etchant, and then the photo resist film is removed. In this way, the conductive pattern having the desired shape is only left on the outer surface of the case. 
     In  FIGS. 5A to 5C , a process of manufacturing a case structure having a conductive pattern according to yet another exemplary embodiment of the present invention. 
     In  FIG. 5A , a case  51  is manufactured. At least one via hole that passes through inner and outer surfaces of the case  51  may be formed in the case  51 . A conductive via is formed in the via hole, and provides electrical contact between conductive patterns formed on the outer surface of the case and a board inside the case. 
     In  FIG. 5B , conductive films  53   a  and  59   a  are formed on the outer surface and the inner surface of the case, respectively. 
     The conductive films  53   a  and  59   a  may be formed by a plating process. In this embodiment, the conductive films are formed on the inner surface and the outer surface of the case. However, the conductive film may be formed at least one surface of the case. 
     In this embodiment, a wall surface of a via hole of the case  51  is plated in a plating process of forming the conductive films  53   a  and  59   a . In this embodiment, a conductive via  52  formed within the via hole can electrically connect the first conductive film  53   a  to a board inside the case. Since the second conductive film  59   a  is formed on the inner surface of the case, the first conductive film  59   a  can be electrically connected to the board mounted on the inside of the case. 
     In  FIG. 5C , conductive patterns  53  and  59  are formed by partially removing the conductive films  53   a  and  59   a  formed on the outer surface and the inner surface of the case. 
     In this embodiment, one conductive pattern is formed on each of the outer surface and the inner surface of the case. However, the number of conductive patterns that are formed on the inner and outer surfaces of the case may be varied. When a plurality of conductive patterns are formed, the conductive patterns may be antenna patterns, ground patterns, or electromagnetic interference shielding patterns. Further, when a plurality of different antenna patterns are formed on the inner and outer surfaces of the case according to this process, a multi-band antenna that can operate according to signals having different frequency bands can be easily implemented. 
     The process of processing the conductive films to form the conductive patterns can be performed by using various kinds of methods. 
     That is, parts of the conductive films  53   a  and  59   a  can be removed by cutting the conductive films  53   a  and  59   a . The conductive films  53   a  and  59   a  may be cut by using a laser. 
     Further, an etching process may be performed on the conductive films  53   a  and  59   a . That is, photo resist films having a desired conductive pattern shape are coated on the conductive films  53   a  and  59   a , parts of the conductive films where the photo resist films are not coated are etched by using an etchant, and then, the photo resist films are removed. In this way, the conductive patterns having the desired shape are only left on the outer surface of the case. 
     As set forth above, according to the exemplary embodiments of the invention, a case structure having a conductive pattern can easily make electrical contact between the conductive pattern and a board inside the case structure, has high reliability, and can form conductive patterns having various shapes. 
     While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.