Abstract:
A non-contact type IC card comprises a core-sheet ( 12 ), made of resin, having first and second surfaces and a hole ( 14 ) penetrating from the first surface to the second surface; a plane coil ( 54 ) formed on the first surface of the core-sheet, the plane coil having respective terminals ( 54   a   , 54   b ) located at an opening region in the hole; a semiconductor element accommodated ( 56 ) in the hole, the semiconductor element having electrodes terminals ( 58 ) electrically connected to the respective terminals of the plane coil; and a pair of over-sheets ( 62 ), made of resin, for covering the first and second surfaces, respectively, to integrally cover the core-sheet with the plane coil and the semiconductor element.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a non-contact type IC card composed in such a manner that over-sheets are attached onto the respective faces of a core-sheet to which a semiconductor element and a plane coil are attached.  
           [0003]    2. Description of the Related Art  
           [0004]    Referring to FIG. 9, an overall arrangement of a conventional non-contact type IC card  50  will be explained below.  
           [0005]    The core sheet  52  is made of polyimide resin.  
           [0006]    The plane coil  54  is formed on one face of the core sheet  52 . The semiconductor element  56  is mounted on one face of the core sheet  52  so that the face of the semiconductor element  56  on which the electrode terminals  58  are formed, that is, the electrode terminal formation face of the semiconductor element  56  can be opposed to one face of the core sheet  52 . The electrode terminals  58  are electrically connected with the respective terminal sections  54   a ,  54   b  ( 54   b  is not shown in the drawing) of the plane coil  54 .  
           [0007]    The over-sheets  62 , on one face of each of which an adhesive sheet  60  is formed, are attached onto the respective faces of the core sheet  52 . These over-sheets  62  and core sheet  52  are subjected to thermal pressing, so that they are integrally heated, pressed and formed into a single body.  
           [0008]    However, the following problems occur in the above mentioned conventional non-contact type IC card. Since the semiconductor element  56  is mounted on the surface of the core sheet  52  and further the over-sheet  62  is put on the semiconductor element  56 , the thickness of the non-contact type IC card is increased. Further, irregularities are caused on the surface of the non-contact type IC card  50  by the semiconductor element  56  mounted on the surface of the core sheet  52 .  
           [0009]    Furthermore, since the core sheet  52  is made of expensive polyimide resin, the unit price of the non-contact type IC card  50  is high.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention is intended to solve the above problems. Accordingly, it is an object of the present invention to provide a non-contact type IC card which is thin and in which irregularities are seldom caused on the surface of non-contact type IC card.  
           [0011]    According to the present invention, there is provided a non-contact type IC card comprising: a core sheet made of resin and having first and second surfaces and a through-hole penetrating from the first surface to the second surface; a plane coil formed on the first surface of the core sheet, the plane coil having respective terminals located at a region in the hole; a semiconductor element accommodated in the hole, the semiconductor element having electrodes terminals electrically connected to the respective terminals of the plane coil; and a pair of over sheets, made of resin, for covering the first and second surfaces, respectively, to integrally cover the core sheet with the plane coil and the semiconductor element.  
           [0012]    Due to the above arrangement, the semiconductor element is accommodated or housed in the through-hole formed on the core-sheet. Therefore, the thickness of the non-contact type IC card can be reduced, and irregularities are seldom caused on the surface of the non-contact type IC card.  
           [0013]    If the resin material is changed from polyimide resin to polyethylene resin which is less expensive than polyimide resin, the unit price of the product can be lowered.  
           [0014]    If the through-hole is filled with sealing material, the semiconductor element can be mechanically reinforced. Therefore, the mechanical strength of the non-contact type semiconductor element can be enhanced when a bending force or an impact is given to the non-contact type semiconductor element.  
           [0015]    The respective terminals can be transversely extending along the first surface of the core sheet over an opening of the hole. Otherwise, respective terminals can be extending into and terminated at the opening region of the hole.  
           [0016]    A thickness of the semiconductor element may be substantially the same or a little smaller than that of the core sheet, so that the semiconductor element can thus be accommodated in the hole within a range of thickness of the core sheet. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    FIGS.  1  to  4  are schematic illustrations for explaining a manufacturing process of an embodiment of the non-contact type IC card of the present invention;  
         [0018]    [0018]FIG. 5 is a plan view for explaining a positional relation between the plane coil and the thorough-hole of the non-contact type IC card shown in FIG. 1;  
         [0019]    [0019]FIG. 6 is an enlarged view showing a portion close to the through-hole illustrated in FIG. 5;  
         [0020]    [0020]FIG. 7 is an enlarged view showing a portion close to the through-hole of the non-contact type IC card in which both terminal sections of the plane coil protrude into the through-hole;  
         [0021]    [0021]FIG. 8 is a schematic illustration for explaining another embodiment of the non-contact type IC card of the present invention; and  
         [0022]    [0022]FIG. 9 is a schematic illustration for explaining an example of the structure of a conventional non-contact type IC card known in the prior art. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    Referring to the appended drawings, preferred embodiments of the non-contact type IC card of the present invention will be explained in detail as follows.  
         [0024]    First, referring to FIGS. 4 and 5, the structure of the non-contact type IC card  10  is explained below. In this connection, like reference characters are used to indicate like parts in these views and the view showing the conventional example, and detailed explanations are omitted here.  
         [0025]    The core sheet  12  is made of resin material, and the through-hole  14  is formed in the core sheet  12  so as to penetrate from the upper surface to the lower surface of the IC card. In this case, when the core sheet  12  is made of polyethylene resin, such as PET, which is less expensive than polyimide resin, the manufacturing cost of the non-contact type IC card  10  can be preferably reduced.  
         [0026]    The plane coil  54  is formed on one face of the core sheet  12 , that is, the plane coil  54  is formed on a lower face of the core sheet  12  as shown in FIG. 4. The plane coil  54  is made of metal such as aluminum or copper, and both terminal sections  54   a ,  54   b  of the plane coil  54  are arranged in the through-hole  14 . To be more specific, in this embodiment, the terminal sections  54   a ,  54   b  of the plane coil  54  are arranged over the through-hole  14 , and at least portions of the terminal sections  54   a ,  54   b  with which the electrode terminals  58  of the semiconductor element  56  are connected are plated with gold.  
         [0027]    The semiconductor element  56  is housed in the through-hole  14  from the other face side (the upper face side shown in FIG. 4) of the core sheet  12  so that the face on which the electrode terminals  58  are formed, that is, the electrode terminal formation face can be directed onto the plane coil  54  side, and a pair of electrode terminals  58  are electrically connected with the terminal sections  54   a ,  54   b  of the plane coil  54  by means of ultrasonic bonding.  
         [0028]    In this case, when a thin semiconductor element  56 , the thickness of which is approximately 50 μ, is used, the semiconductor element  56  does not protrude from the surface of the commonly used core sheet  12  made of PET, the thickness of which is approximately 75 μ. Therefore, no protruding portion are formed on the surface of the non-contact type IC card  10 . Further the thickness of the non-contact type IC card  10  can be reduced. In this connection, in order to prevent the occurrence of irregularities, it is preferable that the thickness of the core sheet  12  and that of the semiconductor element  56  (the thickness of the semiconductor element  56  including the electrode terminals  58 ) are made equal to each other.  
         [0029]    On both faces of the core sheet  12 , in the through-hole  14  of which the semiconductor element  56  is housed, a pair of over-sheets  62  made of resin, on one face of each of which an adhesive layer  60  is formed, are respectively arranged in such a manner that the adhesive layer  60  is located on the core sheet  12  side. These over-sheets  62  are integrated with the core sheet  12  when they are heated and pressed by means of thermal press. In the same manner as that of the core sheet  12 , it is preferable that the over-sheets  62  are made of polyethylene resin which is less expensive than polyimide resin.  
         [0030]    Next, referring to FIGS.  1  to  4 , the manufacturing process of the non-contact type IC card  10  will be explained below.  
         [0031]    In the first process, the through-hole  14  is formed on the core sheet  12  as shown in FIG. 1. In this connection, the profile and size of the through-hole  14  are determined so that the semiconductor element  56  can be housed in the through-hole  14  while consideration is given to the profile of the semiconductor element  56 . In order to prevent the formation of irregularities on the surface of the non-contact type IC card, the thickness of the core sheet  12  is determined by giving consideration to the thickness of the semiconductor element  56 , that is, it is preferable that the thickness of the core sheet  12  is the same as the thickness of the semiconductor element  56 .  
         [0032]    In the second process, a layer of foil  16  of metal such as copper or aluminum is made to adhere onto one face of the core sheet  12 , that is, a layer of foil  16  of metal such as copper or aluminum is made to adhere onto a lower face shown in FIG. 1 as illustrated in FIG. 2.  
         [0033]    In the third process, the layer of metallic foil  16  is etched in a predetermined pattern, so that the plane coil  54  is formed on one face of the core sheet  12 . An example of the plan profile of the plane coil  54  is shown in FIG. 5. The plane coil  54  is arranged so that a portion of the plane coil  54  can be arranged over the through-hole  14 . Especially, in the case of the plane coil  54  of this embodiment, as shown in FIG. 6, the terminal sections  54   a ,  54   b  are also arranged over the through-hole  14 . However, it is possible to adopt such a structure that the terminal sections  54   a ,  54   b  are not arranged over the through-hole  14  but are extended into the through-hole  14  as shown in FIG. 7. If necessary, the terminal sections  54   a ,  54   b  may be plated with gold.  
         [0034]    In the fourth process, the semiconductor element  56  is housed in the through-hole  14  in such a manner that the electrode terminal forming face is directed to the plane coil  54  side as shown in FIG. 3. In this case, the semiconductor element  56  is housed in the through-hole  14  while the semiconductor element  56  is being positioned so that a pair of electrode terminals  58  formed on the electrode terminal face can be contacted with the terminal sections  54   a ,  54   b  of the plane coil  54 . The electrode terminals  58  of the semiconductor element  56  are electrically connected with the terminal sections  54   a ,  54   b  of the plane coil  54  by means of ultrasonic bonding.  
         [0035]    In the fifth process, the over-sheets  62  made of polyethylene resin, on only one face of which the adhesive layer  60  is formed, are made to adhere onto both faces of the core sheet  12 , in the through-hole  14  of which the semiconductor element  56  is housed. These over-sheets  62  are integrated with both faces of the core sheet  12  when they are heated and pressed by means of thermal press as shown in FIG. 4. In this way, the non-contact type IC card illustrated in FIG. 4 can be manufactured.  
         [0036]    When a process in which the sealing material is filled in the through-hole  14  is provided between the fourth and the fifth process, it becomes possible to manufacture the non-contact type IC card  20  in which the periphery of the semiconductor element  56  is reinforced by the sealing material  18  as shown in FIG. 8.  
         [0037]    It should be understood by those skilled in the art that the foregoing description relates to some of the preferred embodiments of the disclosed invention, and that various changes and modifications may be made to the invention without departing from the spirit and scope thereof.