Abstract:
Disclosed herein is a rigid-flexible substrate including: a rigid area including a circuit layer; a flexible area formed at one end of the rigid area; and a raw material formed over the flexible area and having indentation formed on a surface thereof.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2012-0048139, filed on May 7, 2012, entitled “Rigid-Flexible Printed Circuit Board And Method For Manufacturing Thereof” which is hereby incorporated by reference in its entirety into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a rigid-flexible printed circuit board and a method for manufacturing the same. 
         [0004]    2. Description of the Related Art 
         [0005]    With the recent development of IT industries, contents such as multimedia, and the like, are increased and with the development of network communication technology, a demand for a high-density, high-integration printed circuit board technology for ultra-high speed communication has increased. In addition, as a demand for slimness and lightness of mobile devices is increased, a demand for a technology for implementing miniaturization, lightness, thinness, multi-function, and various designs of the printed circuit board has increased. 
         [0006]    As described above, as a design of high-density electronic devices is diversified, applications of a rigid-flexible printed circuit board have been increased. 
         [0007]    The rigid-flexible printed circuit board uses both of a multi-layer printed circuit board technology and a flexible technology. That is, the rigid-flexible printed circuit board includes a flexible area in which circuit patterns are formed on a flexible film having flexibility and a rigid area in which physical hardness is increased by multi-layering insulating layers on a flexible film. (U.S. Pat. No. 5,362,534). 
         [0008]    The rigid-flexible printed circuit board can be wired in a three-dimensional structure and easily assemble and therefore, can be applied to notebooks, digital cameras, mobile communication terminals, and the like. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention has been made in an effort to provide a rigid-flexible substrate and a method for manufacturing the same capable of improving adhesion of raw materials. 
         [0010]    According to a preferred embodiment of the present invention, there is provided a rigid-flexible substrate, including: a rigid area including a circuit layer; a flexible area formed at one end of the rigid area; and a raw material formed over the flexible area and having indentation formed on a surface thereof. 
         [0011]    The raw material may be an electronic element. 
         [0012]    The raw material may be an electro magnetic interference (EMI) device. 
         [0013]    According to a preferred embodiment of the present invention, there is provided a method for manufacturing a rigid-flexible substrate, including: providing a base substrate including a rigid area including a circuit layer and a flexible area; forming a raw material in the flexible area; forming a first subsidiary material over the rigid area and the flexible area; forming a first jig on the first subsidiary material; providing heat to the base substrate on which the raw material, the first subsidiary material, and the first jig are formed; and removing the first subsidiary material and the first jig. 
         [0014]    In the forming of the raw material, the raw material may be an electronic element. 
         [0015]    In the forming of the raw material, the raw material may be an electro magnetic interference (EMI) element. 
         [0016]    In the forming of the first subsidiary material, the subsidiary material may be formed of a thermoplastic material. 
         [0017]    In the forming of the first subsidiary material, the subsidiary material may be formed of poly vinyl chloride (PVC). 
         [0018]    In the forming of the first jig, the first jig may include a first body that is extendedly formed longitudinally and a first protrusion that is formed beneath a portion of the first body and is protruded from the first body. 
         [0019]    In the forming of the first jig, the first protrusion may be disposed over an area in which the raw material is disposed. 
         [0020]    The method may further include: after the forming of the first subsidiary material, forming a second subsidiary material under the rigid area and the flexible area. 
         [0021]    In the forming of the second subsidiary material, the second subsidiary material may be formed of a thermoplastic material. 
         [0022]    In the forming of the second subsidiary material, the second subsidiary material may be formed of poly vinyl chloride (PVC). 
         [0023]    The method may further include: after the forming of the second subsidiary material, forming a second jig beneath the second subsidiary material. 
         [0024]    In the forming of the second jig, the second jig may include a second body that is extendedly formed longitudinally and a second protrusion that is formed beneath a portion of the second body and is protruded from the second body. 
         [0025]    In the forming of the second jig, the second protrusion may be disposed under an area in which the raw material is disposed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0027]      FIGS. 1 to 6  are diagrams showing a method for manufacturing a rigid-flexible substrate according to a preferred embodiment of the present invention; 
           [0028]      FIGS. 7 to 12  are diagrams showing the method for manufacturing a rigid-flexible substrate according to the preferred embodiment of the present invention; 
           [0029]      FIG. 13  is a diagram showing a rigid-flexible substrate when jigs are not used according to the embodiment of the present invention; and 
           [0030]      FIG. 14  is a diagram showing a rigid-flexible substrate when jigs are used according to the embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    The objects, features and advantages of the present invention will be more clearly understood from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant descriptions thereof are omitted. Further, in the following description, the terms “first”, “second”, “one side”, “the other side” and the like are used to differentiate a certain component from other components, but the configuration of such components should not be construed to be limited by the terms. Further, in the description of the present invention, when it is determined that the detailed description of the related art would obscure the gist of the present invention, the description thereof will be omitted. 
         [0032]    Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. 
         [0033]      FIGS. 1 to 6  are diagrams showing a method for manufacturing a rigid-flexible substrate according to a preferred embodiment of the present invention. 
         [0034]    Referring to  FIG. 1 , a rigid area  110  including a circuit layer (not shown) and a base substrate  100  including a flexible area  120  may be provided. 
         [0035]    The flexible area  120  may be formed as a flexible substrate  121  on which the circuit layer (not shown) is formed. 
         [0036]    The flexible substrate  121  may be formed of an insulating material. In addition, the flexible substrate  121  may have excellent flexibility. The flexible substrate  121  may be formed of polyimide. However, the material of the flexible substrate  121  is not limited to polyimide. That is, as the material of the flexible substrate  121  any insulating material having property including flexibility can be used. The flexible substrate  121  may include a circuit layer (not shown). 
         [0037]    The rigid area  110  may be formed as a rigid substrate  111  on which the circuit layer (not shown) is formed. In addition, the rigid area  110  may include the flexible substrate  121 . The rigid area  110  may include the flexible substrate  121 , insulating layers (not shown) on top and bottom of the flexible substrate  121 , and the circuit layer (not shown) including circuit patterns, vias, and the like. In this case, the rigid area  110  may be formed to have a thickness thicker than that of the flexible area  120 . 
         [0038]    Referring to  FIG. 2 , a raw material  130  may be formed in the flexible area  120 . The raw material  130  may be disposed on the top of the flexible substrate  121  of the flexible area  120 . The bottom of the raw material  130  contacting the flexible substrate  121  may be previously formed with an adhesive material. The raw material  130  may be electronic elements. For example, the raw material  130  may be an electro magnetic interference (EMI) element for preventing a function from being degraded due to noises. The raw material  130  is not limited to the EMI element. That is, as the raw material  130 , any material which can be bonded to the flexible substrate can be used. 
         [0039]    Referring to  FIG. 3 , a first subsidiary material  141  may be formed over the rigid area  110  and the flexible area  120 . The first subsidiary material  141  may extend from above the rigid area  110  to the top of the raw material  130  that is formed in the flexible area  120 . In this case, the first subsidiary material  141  may be formed so as to be bonded to the top of the base substrate  100 . 
         [0040]    The first subsidiary material  141  may be formed of a thermoplastic material. For example, the first subsidiary material  141  may be formed of poly vinyl chloride (PVC). The first subsidiary material  141  may serve to transfer heat to the raw material  130 . The first subsidiary material  141  is formed of a thermoplastic material and thus, the shape thereof may be changed in a high-temperature state. 
         [0041]    Referring to  FIG. 4 , a first jig  210  may be formed on the first subsidiary material  141 . 
         [0042]    The first jig  210  may be formed to include a first body  211  and a first protrusion  212 . 
         [0043]    The first body  211  may be extendedly formed longitudinally. A length of the first body  211  may be formed enough to partially cover at least the rigid area  110  and the flexible area  120 . For example, the first body  211  may be formed to cover a portion or all of the rigid area  110 . Further, the first body  211  may be formed to cover a portion or all of the flexible area  120 . In this case, when the first body  211  partially covers the flexible area  120 , the first body  211  may be formed to have a length enough to cover an area in which the raw material  130  is formed. 
         [0044]    The first protrusion  212  may be formed beneath the first body  211 . The first protrusion  212  may be protruded from the first body  211 . In this case, the first protrusion  212  may be formed to have a thickness enough to contact a bottom surface of the first subsidiary material  141  to a top surface of the raw material  130 . 
         [0045]    When the first jig  210  is disposed on the first subsidiary material  141 , the first protrusion  212  of the first jig  210  may be disposed on the raw material  130 . 
         [0046]    The first jig  210  may be formed of a copper clad laminate (CCL), an epoxy resin, and the like. For example, the first body  211  of the first jig  210  is formed of the CCL and the first protrusion  212  may be formed of the epoxy resin. However, the first jig  210  is not limited thereto and therefore, may be formed of a material having heat resistance but does not include flexibility. 
         [0047]    Referring to  FIG. 5 , heat may be transferred to the base substrate  100 . 
         [0048]    Heat may transfer to the base substrate  100  on which the raw material  130 , the first subsidiary material  141 , and the first jig  210  are formed. As described above, as the base substrate  100  is in a high temperature state, the shape of the first subsidiary material  141  can be modified. 
         [0049]    For example, when the rigid area  110  is formed to have a thickness thicker than that of the flexible area  120 , there may be a difference in a height between the rigid area  110  and the flexible area  120 . In this case, the first subsidiary material  141  formed over the rigid area  110  and the flexible area  120  may be bent in the high-temperature state due to the height difference therebetween. That is, the first subsidiary material  141  may extend downwardly from the flexible area  120 . The first subsidiary material  141  may extend to the top surface of the raw material  130  of the flexible area  120 . In this case, the first subsidiary material  141  may contact the top surface of the raw material  130 . 
         [0050]    In addition, the first subsidiary material  141  may be pressed by the first jig  210  formed thereon. That is, the first protrusion  212  of the first jig  210  may press the first subsidiary material  141  formed therebeneath. As such, as the first subsidiary material  141  is pressed by the first protrusion  212  of the first jig  210 , a contact area between the first subsidiary material and the top surface of the raw material  130  may be increased. 
         [0051]    As the contact area between the first subsidiary material  141  and the raw material  130  is increased by the high temperature and the pressure of the first jig  210 , heat is sufficiently transferred to the raw material  130  through the first subsidiary material  141 . 
         [0052]    The raw material  130  may be supplied with sufficient heat through the first subsidiary material  141  to increase an adhesion of an adhesive material formed on the bottom surface of the raw material  130 . The raw material  130  is supplied with sufficient heat to increase adhesion and may be reliably bonded to the flexible substrate  121 . 
         [0053]    Referring to  FIG. 6 , the first subsidiary material  141  and the first jig  210  may be removed. 
         [0054]    After the raw material  130  is reliably bonded to the flexible substrate  121 , the first subsidiary material  141  and the first jig  210  may be removed. The first subsidiary material  141  and the first jig  210  may be removed by being detached or stripped from the base substrate  100  and the raw material  130 . 
         [0055]      FIGS. 7 to 12  are diagrams showing the method for manufacturing a rigid-flexible substrate according to the preferred embodiment of the present invention. 
         [0056]    Referring to  FIG. 7 , the rigid area  110  including the circuit layer (not shown) and the base substrate  100  including the flexible area  120  may be provided. 
         [0057]    The flexible area  120  may be formed as the flexible substrate  121  on which the circuit layer (not shown) is formed. 
         [0058]    The flexible substrate  121  may be formed of an insulating material. In addition, the flexible substrate  121  may have excellent flexibility. The flexible substrate  121  may be formed of polyimide. However, the material of the flexible substrate  121  is not limited to polyimide. That is, as the material of the flexible substrate  121  any insulating material having property including the flexibility can be used. The flexible substrate  121  may include the circuit layer (not shown). The flexible substrate  121  may include the circuit layer (not shown). 
         [0059]    The rigid area  110  may be formed as the rigid substrate  111  on which the circuit layer (not shown) is formed. In addition, the rigid area  110  may include the flexible substrate  121 . In this case, the flexible substrate  121  may include the circuit layer (not shown). The rigid area  110  may include the flexible substrate  121 , the insulating layers (not shown) on the top and bottom of the flexible substrate  121 , and the circuit layer (not shown) including circuit patterns, vias, and the like. In this case, the rigid area  110  may be formed to have a thickness thicker than that of the flexible area  120 . 
         [0060]    Referring to  FIG. 8 , the raw material  130  may be formed in the flexible area  120 . The raw materials  130  may be disposed on the top of the flexible substrate  121  of the flexible area  120 . The bottom of the raw material  130  contacting the flexible substrate  121  may be previously formed with an adhesive material. The raw material  130  may be electronic elements. For example, the raw material  130  may be the electro magnetic interference (EMI) element for preventing a function from being degraded due to noises. The raw material  130  is not limited to the EMI element. That is, as the raw material  130 , any material which can be bonded to the flexible substrate can be used. 
         [0061]    Referring to  FIG. 9 , the first subsidiary material  141  and the second subsidiary material  145  may be formed on the base substrate  100  on which the raw material  130  is formed. The first subsidiary material  141  may be formed over the rigid area  110  and the flexible area  120 . The first subsidiary material  141  may extend from above the rigid area  110  to the top of the raw material  130  that is formed in the flexible area  120 . The second subsidiary material  145  may be formed under the rigid area  110  and the flexible area  120 . The second subsidiary material  145  may extend from under the rigid area  110  to the bottom of the raw material  130  that is formed in the flexible area  120 . The first subsidiary material  141  and the second subsidiary material  145  may be formed so as to be bonded to the top and bottom of the base substrate  100 . 
         [0062]    The first subsidiary material  141  and the second subsidiary material  145  may be made of a thermoplastic material. For example, the first subsidiary material  141  and the second subsidiary material  145  may be made of poly vinyl chloride (PVC). The first subsidiary material  141  and the second subsidiary material  145  may serve to transfer heat to the raw material  130 . The first subsidiary material  141  and the second subsidiary material  145  is made of a thermoplastic material and thus, the shape thereof may be changed in a high-temperature state. 
         [0063]    Referring to  FIG. 10 , the first jig  210  may be formed on the first subsidiary material  141 . In addition, a second jig  220  may be formed beneath the second subsidiary material  145 . 
         [0064]    The first jig  210  may be formed to include a first body  211  and a first protrusion  212 . 
         [0065]    The first body  211  may be extendedly formed longitudinally. The length of the first body  211  may be formed enough to partially cover at least the rigid area  110  and the flexible area  120 . In this case, when the first body  211  partially covers the flexible area  120 , the first body  211  may be formed to have a length enough to cover an area in which the raw material  130  is formed. 
         [0066]    The first protrusion  212  may be formed under the first body  211 . The first protrusion  212  may be protruded from the first body  211 . In this case, the first protrusion  212  may be formed to have a thickness enough to contact a bottom surface of the first subsidiary material  141  to a top surface of the raw material  130 . 
         [0067]    The second jig  220  may be formed to include a second body  221  and a second protrusion  222 . 
         [0068]    The second body  221  may be extendedly formed longitudinally. The length of the second body  221  may be formed enough to partially cover the rigid area  110  and the flexible area  120  at least. In this case, when the second body  221  partially covers the flexible area  120 , the second body  221  may be formed to have a length enough to cover an area in which the raw material  130  is formed. 
         [0069]    The second protrusion  222  may be formed on the second body  221 . The second protrusion  222  may be protruded from the second body  221 . In this case, the second protrusion  222  may be formed to have a thickness enough to contact a top surface of the second subsidiary material  145  to a bottom surface of the flexible substrate  121 . 
         [0070]    When the first jig  210  is disposed on the first subsidiary material  141 , the first protrusion  212  of the first jig  210  may be disposed on the raw material  130 . In addition, when the second jig  220  is disposed beneath the first subsidiary material  145 , the second protrusion  222  of the second jig  220  may be disposed under the raw material  130 . In this case, the first protrusion  212  of the first jig  210  and the second protrusion  222  of the second jig  220  may be disposed to face each other. 
         [0071]    The first jig  210  and the second jig  220  may be formed of a copper clad laminate (CCL), an epoxy resin, and the like. For example, the first body  211  of the first jig  210  is formed of the CCL and the first protrusion  212  may be formed of the epoxy resin. However, the first jig  210  is not limited thereto and therefore, may be formed of a material having heat resistance but does not include flexibility. The second jig  220  may be formed of the same material as the first jig  210 . 
         [0072]    Referring to  FIG. 11 , heat may be transferred to the base substrate  100 . 
         [0073]    Heat may transfer to the base substrate  100  on which the raw material  130 , the first subsidiary material  141 , the second subsidiary material  145 , the first jig  210 , and the second jig  220  are formed. As described above, as the base substrate  100  is in a high temperature state, the shape of the first subsidiary material  141  and the second subsidiary material  145  can be modified. 
         [0074]    For example, when the rigid area  110  is formed to have a thickness thicker than that of the flexible area  120 , there may be a difference in a height between the rigid area  110  and the flexible area  120 . In this case, the first subsidiary material  141  and the second subsidiary material  145  formed over and under the rigid area  110  and the flexible area  120  may be bent in the high-temperature state due to the height difference therebetween. 
         [0075]    The first subsidiary  141  may extend to the top surface of the raw material  130  of the flexible area  120 . In this case, the first subsidiary material  141  may contact the top surface of the raw material  130 . 
         [0076]    The second subsidiary material  145  may extend to the flexible substrate  121  of the flexible area  120 . In this case, the second subsidiary material  145  may contact the bottom surface of the flexible substrate  121 . 
         [0077]    In addition, the first subsidiary material  141  may be pressed by the first jig  210  formed thereon. That is, the first protrusion  212  of the first jig  210  may press the first subsidiary material  141  formed therebeneath. As such, as the first subsidiary material  141  is pressed by the first protrusion  212  of the first jig  210 , a contact area between the first subsidiary material  141  and the top surface of the raw material  130  may be increased. 
         [0078]    The second subsidiary material  145  may be pressed by the second jig  220  formed therebeneath. That is, the second protrusion  222  of the second jig  220  may press the second subsidiary material  145  formed thereon. As such, as the second subsidiary material  145  is pressed by the second protrusion  222  of the second jig  220 , a contact area between the second subsidiary material  145  and the bottom surface of the flexible substrate  121  on which the raw material  130  is formed may be increased. 
         [0079]    As the contact area between the first subsidiary material  141  and the raw material  130  is increased by the high temperature and the pressure of the first jig  210  and the second jig  220 , heat is sufficiently transferred to the raw material  130  through the first subsidiary material  141 . 
         [0080]    The raw material  130  may be supplied with sufficient heat through the first subsidiary material  141  to increase an adhesion of an adhesive material formed on the bottom surface of the raw material  130 . The raw material  130  is supplied with sufficient heat to increase adhesion and may be reliably bonded to the flexible substrate  121 . 
         [0081]    According to the preferred embodiment of present invention, the first subsidiary material  141  and the second subsidiary material  145  simultaneously may press the top and bottom of the raw material  130  by the first jig  210  and the second jig  220 . That is, the raw material  130  and the flexible substrate  121  may be more firmly bonded to each other. Therefore, the flexible substrate  121  may be improved, in the case in which two subsidiary materials and jigs are used, the adhesion between the raw material  130  and the flexible substrate  121  and than in the case in which one subsidiary material and a jig are used. 
         [0082]    Referring to  FIG. 12 , the first subsidiary material  141 , the second subsidiary material  145 , the first jig  210 , and the second jig  220  may be removed. 
         [0083]    After the raw material  130  is reliably bonded to the flexible substrate  121 , the first subsidiary material  141 , the second subsidiary material  145 , the first jig  210 , and the second jig  220  may be removed. The first subsidiary material  141 , the second subsidiary material  145 , the first jig  210 , and the second jig  220  may be removed by being detached or stripped from the base substrate  100  and the raw material  130 . 
         [0084]      FIG. 13  is a diagram showing the surface of the rigid-flexible substrate when the jigs are not used according to the embodiment of the present invention. 
         [0085]    Referring to  FIG. 13 , it can confirm the surface  122  of the flexible substrate  121  when the jigs are not used. The flexible substrate  121  may be formed with wrinkles since the surface  122  thereof is melted during a high-temperature high-pressure process. Referring to  FIG. 13 , it can be confirmed that the surface  122  of the flexible substrate  121  may be formed with wrinkles. When the raw material  130  of  FIG. 3  is bonded to the surface of the flexible substrate  121  formed with wrinkles, a gap may occur between the surface  122  of the flexible substrate  121  and the bottom surface of the raw material  130  of  FIG. 3 . In this case, when the raw material  130  of  FIG. 3  is not sufficiently supplied with heat and pressure from the first subsidiary material  141  of  FIG. 3 , it is difficult to reliably bond between the flexible substrate  121  the raw material  130  of  FIG. 3 . 
         [0086]      FIG. 14  is a diagram showing the surface of the rigid-flexible substrate when the jigs are used according to the embodiment of the present invention. 
         [0087]    Referring to  FIG. 14 , it can confirm the surface  122  of the flexible substrate  12  when the jigs are not used. The flexible substrate  121  may be formed with wrinkles since the surface  122  thereof is melted during a high-temperature high-pressure process as shown in  FIG. 13 . When the raw material  130  of  FIG. 5  is bonded to the surface  122  of the flexible substrate  121  formed with wrinkles, pressure may be applied to the first subsidiary material  141  of  FIG. 4  that is formed on the raw material  130  of  FIG. 5 , by using the first jig  210  of  FIG. 5 . The first subsidiary material  141  of  FIG. 4  may apply pressure to the flexible substrate  121  and the raw material  130  of  FIG. 5 , by the pressure of the first jig  210  of  FIG. 5 . In this case, the flexible substrate  121  and the raw material  130  of  FIG. 5  may be applied with pressure from the first subsidiary material  141  of  FIG. 5  and the first jig  210  of  FIG. 5  to be bonded to each other. As described above, the surface  122  of the flexible substrate  121  is bonded to the bottom of the raw material  130  of  FIG. 5  by pressure and thus, the surface  122  of the flexible substrate  121  may be flat as shown in  FIG. 14 . As the surface  122  of the flexible substrate  121  is flat, the contact area between the surface  122  of the flexible substrate  121  and the raw material  130  of  FIG. 5  may be increased. As described above, when sufficient heat for bonding is supplied from the first subsidiary material  141  of  FIG. 5  in the state in which the contact area between the surface  122  of the flexible substrate  121  and the raw material  130  of  FIG. 5  is increased, the flexible substrate  121  and the raw material  130  of  FIG. 5  can be reliably bonded to each other. 
         [0088]    In the preferred embodiments of  FIGS. 13 and 14 , the first jig  210  and the first subsidiary material  141  are described by way of example, but are not limited thereto. That is, when the first jig  210  and the first subsidiary material  141  are used, the second jig  220  and the second subsidiary material  142  may be simultaneously used. 
         [0089]    According to the preferred embodiment of the present invention, when the raw material is bonded to the flexible area of the base substrate, the jigs formed with the protrusions are used and thus, the sufficient heat may be transferred to the raw material through the subsidiary materials. Therefore, it is prevent the raw material from being lifted due to the increase in the adhesion of the raw material and the raw material from separating from each other due to pores formed between the raw material and the base substrate, and the like. 
         [0090]    According to the rigid-flexible substrate and the method for manufacturing the same, it is possible to improve the adhesion of the raw material bonded to the flexible area. 
         [0091]    Although the embodiments of the present invention have been disclosed for illustrative purposes, it will be appreciated that the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. 
         [0092]    Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims.