Patent Publication Number: US-6669796-B2

Title: Method of manufacturing laminated ceramic electronic component, and laminated ceramic electronic component

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a method for manufacturing a laminated ceramic electronic component such as a laminated inductor or laminated common-mode choke coil and, more particularly, to a method for manufacturing a laminated ceramic electronic component in which a lamination step is performed using a transfer technique, and a laminated ceramic electronic component that is manufactured by this manufacturing method. 
     2. Description of the Related Art 
     Conventional miniaturized inductor components are monolithic coils that are produced using a monolithic ceramic sintering technique. For example, Japanese Unexamined Patent Application Publication No. 56-155516 discloses an open magnetic circuit type monolithic coil as a monolithic inductor. According to the disclosure of this Japanese Application, a magnetic ceramic paste is printed a plurality of times, thereby producing a bottom external layer. A conductor forming a portion of coil, and a magnetic paste are alternately printed. A coil conductor is produced in this way. In the course of printing the coil conductor, a non-magnetic paste is also printed. After the coil conductor is printed, a magnetic paste is printed a plurality of times to form a top external layer. A laminate structure thus produced is pressed in the direction of thickness, and is then sintered. An open magnetic circuit type monolithic coil is thus produced. 
     In the above-described method of manufacturing the open magnetic circuit type monolithic coil, the laminate structure is obtained by printing the magnetic paste, the non-magnetic paste, and an electrically conductive paste for lamination. In such a lamination-by-printing method, a layer is printed on an already printed layer. The height of a portion where a conductor is printed to form the coil conductor is different from the height of the remaining portion, and the flatness of the printed underlayer is not sufficient. For this reason, the magnetic paste, the non-magnetic paste, or the conductive paste tends to run when they are printed, and a desired monolithic coil cannot be produced with high accuracy. 
     In the lamination-by-printing method, the magnetic paste, the non-magnetic paste, and the electrically conductive paste used therein in the respective steps require sufficient contact and closeness with the underlayer thereof, and the number of usable types of paste is limited. 
     In the lamination-by-printing method, an already printed paste needs to be dried to some degree prior to the printing of the next paste. The printing process thus requires much time, and involves complex steps, thereby making it very difficult to reduce the costs of the monolithic coil. 
     SUMMARY OF THE INVENTION 
     In order to overcome the problems described above, preferred embodiments of the present invention provide a reliable, low-cost and simple-structured, laminated ceramic electronic component, and method of manufacturing the same, which allows a desired conductor and a sintered ceramic internal structure to be produced with high accuracy. 
     According to a preferred embodiment of the present invention, a method for manufacturing a laminated ceramic electronic component includes the steps of preparing a first transfer member which includes a conductor-attached composite green sheet and a first carrier film supporting the composite green sheet, the composite ceramic green sheet, including a first ceramic region and a second ceramic region made of a ceramic that is different from a ceramic of the first ceramic region, having a conductor on one surface thereof, preparing a second transfer member which includes a ceramic green sheet and a second carrier film supporting the ceramic green sheet, a first transfer step of transferring the ceramic green sheet of at least one second transfer member on a lamination stage, a second transfer step of transferring the conductor-attached composite green sheet of at least one first transfer member to at least one ceramic green sheet already laminated, a third transfer step of transferring the ceramic green sheet of at least one second transfer member to the conductor-attached composite green sheet already laminated, and sintering a laminated body obtained from the first transfer step through the third transfer step. 
     In another preferred embodiment of the present invention, a method for manufacturing a laminated ceramic electronic component further includes the step of preparing a plurality of first transfer members, and forming a via hole electrode in the composite ceramic green sheet of the conductor-attached composite green sheet of at least one first transfer member so that the conductors are connected among a plurality of conductor-attached composite green sheets subsequent to lamination. 
     In another preferred embodiment of the present invention, a plurality of conductors are connected through the via hole electrodes to form a coil conductor when the plurality of conductor-attached composite green sheets are laminated. 
     It is preferable that the first ceramic region is made of a magnetic ceramic, and the second ceramic region is made of a non-magnetic ceramic. 
     Also, it is preferable that the ceramic sheet of the second transfer member is made of a magnetic ceramic. 
     The conductor is preferably formed on the top surface of the composite green sheet in the first transfer member. 
     The conductor is preferably formed on the bottom surface of the composite green sheet in the first transfer member. 
     The method for manufacturing a laminated ceramic electronic component preferably includes the step of forming the first ceramic region by printing a magnetic ceramic paste and the second ceramic region by printing a non-magnetic ceramic paste. 
     In a further preferred embodiment of the present invention, the method for manufacturing a laminated ceramic electronic component includes forming the first and second ceramic regions except a region where a via hole electrode is to be formed, and thereafter filling the region with an electrically conductive paste to form the via hole electrode. 
     In another preferred embodiment of the present invention, the method for manufacturing a laminated ceramic electronic component includes forming a through hole in which a via hole electrode is to be formed after preparing the composite ceramic green sheet, and filling the through hole with an electrically conductive paste to form the via hole electrode. 
     The ceramic green sheet of the second transfer member is preferably produced by forming a ceramic green sheet on the second carrier film. 
     In a further preferred embodiment of the present invention, a method for manufacturing a laminated ceramic electronic component further includes preparing a third transfer member which includes a composite ceramic green sheet including the first ceramic region and the second ceramic region, and a third carrier film supporting the composite ceramic green sheet, and transferring the composite ceramic green sheet from at least one third transfer member between the first transfer step and the third transfer step. 
     In yet another preferred embodiment of the present invention, a laminated ceramic electronic component includes a sintered ceramic body produced according to the manufacturing method according to preferred embodiments of the present invention described above, a plurality of external electrodes arranged on the external surface of the sintered ceramic body, and respectively electrically connected to conductors within the sintered ceramic body. 
     Another preferred embodiment of the present invention provides a laminated ceramic electronic component including a sintered ceramic body, at least one coil conductor arranged within the sintered ceramic body and including a coil portion and first and second lead-out portions respectively connected to both ends of the coil portion, a plurality of external electrodes arranged on the external surface of the sintered ceramic body and electrically connected to an end of the first lead-out portion or an end of the second lead-out portion, wherein the sintered ceramic body includes a magnetic ceramic and a non-magnetic ceramic, the coil portion of the coil conductor is coated with a non-magnetic ceramic, and the first and second lead-out portions of the coil conductor are coated with a non-magnetic ceramic. 
     Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the attached drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing the external appearance of a laminated ceramic electronic component of a first preferred embodiment of the present invention; 
     FIGS. 2A-2C are sectional views of the laminated ceramic component, respectively taken along line A—A, line B—B, and line C—C in FIG. 1; 
     FIGS. 3A-3F are plan views illustrating composite green sheets prepared for the production of the laminated ceramic electronic component of the first preferred embodiment of the present invention; 
     FIGS. 4A-4F are plan views diagrammatically illustrating composite green sheets prepared for the production of the laminated ceramic electronic component of the first preferred embodiment of the present invention; 
     FIGS. 5A-5C are plan views illustrating a manufacturing process for manufacturing the composite green sheet according to the first preferred embodiment of the present invention; 
     FIGS. 6A-6D are plan views illustrating steps for preparing a first transfer member prepared in the first preferred embodiment of the present invention; 
     FIGS. 7A-7C are plan views illustrating a manufacturing process for manufacturing a conductor-attached composite green sheet according to the first preferred embodiment of the present invention; 
     FIGS. 8A-8C are sectional views illustrating the transfer of a ceramic green sheet from a second transfer member in the first preferred embodiment of the present invention; 
     FIGS. 9A and 9B are sectional views illustrating steps for transferring the conductor-attached green sheet from the first transfer member in the first preferred embodiment of the present invention; 
     FIG. 10 is a perspective view showing a laminated ceramic electronic component of a second preferred embodiment of the present invention; 
     FIGS. 11A and 11B are sectional views of the laminated ceramic electronic component, respectively taken along line A—A and line B—B in FIG. 10; 
     FIGS. 12A-12D are plan views showing green sheets that are laminated in the second preferred embodiment of the present invention; 
     FIGS. 13A and 13B are plan views respectively showing a conductor-attached composite green sheet and a composite green sheet prepared in the second preferred embodiment of the present invention; 
     FIGS. 14A-14D are plan views respectively showing composite green sheets used in a laminate forming a second coil in the second preferred embodiment of the present invention; 
     FIG. 15 is a perspective view showing a laminated ceramic electronic component of a modification of the second preferred embodiment of the present invention; 
     FIGS. 16A and 16B are sectional views of the modification of the second preferred embodiment, respectively taken along line A—A and line B—B in FIG. 15; 
     FIG. 17 is a perspective view showing a laminated ceramic electronic component of a third preferred embodiment of the present invention; 
     FIGS. 18A-18C are sectional views of the laminated ceramic electronic component, respectively taken along line A—A, line B—B, and line C—C in FIG. 17; 
     FIG. 19 is a perspective view showing the external appearance of a laminated ceramic electronic component of a fourth preferred embodiment of the present invention; 
     FIGS. 20A-20C are sectional views of the laminated ceramic electronic component, respectively taken along line A—A, line B—B, and line C—C in FIG. 19; 
     FIG. 21 is a perspective view showing the external appearance of a laminated ceramic electronic component of a fifth preferred embodiment of the present invention; 
     FIGS. 22A-22C are sectional views of the laminated ceramic electronic component, respectively taken along line A—A, line B—B, and line C—C in FIG. 21; 
     FIG. 23 is an elevational sectional view of a laminated ceramic electronic component of a sixth preferred embodiment of the present invention; 
     FIG. 24 is an elevation sectional view of a modification of the laminated ceramic electronic component of the sixth preferred embodiment shown in FIG. 23; and 
     FIG. 25 is an elevational sectional view of another modification of the laminated ceramic electronic component of the sixth preferred embodiment shown in FIG.  23 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention will become apparent from the following description of preferred embodiments with reference to the drawings. 
     FIG. 1 is a perspective view showing the external appearance of a laminated ceramic electronic component  1  of a first preferred embodiment of the present invention. The laminated ceramic electronic component  1  is preferably a closed magnetic circuit type, common-mode monolithic choke coil. 
     The laminated ceramic electronic component  1  includes a substantially rectangular, sintered ceramic body  2 . First and second external electrodes  3  and  4 , and third and fourth external electrodes  5  and  6  are disposed on the sintered ceramic body  2 . The external electrodes  3  and  4  are provided on one end surface of the sintered ceramic body  2 , and the external electrodes  5  and  6  are provided on the other end surface of the sintered ceramic body  2  opposite to the first end surface having the external electrodes  3  and  4 . 
     FIG. 2A is a sectional view of the laminated ceramic component, taken along line A—A in FIG. 1, FIG. 2B is a sectional view of the laminated ceramic component, taken along line B—B in FIG. 1, and FIG. 2C is a sectional view of the laminated ceramic component, taken along line C—C in FIG.  1 . 
     The sintered ceramic body  2  includes a magnetic ceramic  7  and a non-magnetic ceramics  8 . First and second coils  9  and  10  are disposed within the non-magnetic ceramics  8 . The coils  9  and  10  are wound within the sintered ceramic body  2  in the direction of width. A top lead-out portion  9   a  of the coil  9  is routed out to an end surface  2   a  of the sintered ceramic body  2 , and a bottom lead-out portion  9   b  of the coil  9  is routed out to an end surface  2   b  of the sintered ceramic body  2 . A top lead-out portion  10   a  of the coil  10  is also routed out to the end surface  2   a,  while a bottom lead-out portion  10   b  is routed to the end surface  2   b.    
     FIG. 2B shows a section along line B—B in FIG. 1, in which the coil lead-out portions  9   a  and  9   b  are represented by dotted lines. The coil lead-out portions  10   a  and  10   b  are represented by dot-dash chain lines to indicate that the coil lead-out portions  10   a  and  10   b  are not present in the plane of the page of FIG. 2B but actually lie in a section that is parallel to and above the page. 
     The same is true of FIG. 11B, FIG. 16B, FIG. 18B, FIG. 20B, and FIG.  22 B. 
     The lead-out portions  9   a  and  10   a  of the coils  9  and  10  that are led out to the end surface  2   a  are respectively electrically connected to the external electrodes  3  and  4 . On the other hand, the lead-out portions  9   b  and  10   b  of the coils  9  and  10  are respectively electrically connected to the external electrodes  5  and  6  on the end surface  2   b.    
     The first coil  9  and the second coil  10  are spaced in the direction of thickness within the sintered ceramic body  2 . The coils  9  and  10  disposed within the non-magnetic ceramic  8  are covered with the magnetic ceramic  7  from above and from below. 
     A method of manufacturing the laminated ceramic electronic component  1  of this preferred embodiment will now be described with reference to FIG.  3 A through FIG.  9 B. 
     External layers  2   c  and  2   d  shown in FIGS. 2A-2C are now produced. A carrier film having a substantially rectangular magnetic ceramic green sheet is prepared to form a plurality of second transfer members. 
     Sheets shown in FIGS. 3A-3F and FIGS. 4A-4F are prepared to form a section sandwiched between the external layers  2   c  and  2   d.  A composite green sheet  11  shown in FIG. 3A includes a magnetic ceramic region  12  defining a first ceramic region and a non-magnetic ceramic region  13  defining a second ceramic region. Referring to FIG.  3 B through FIG. 7C, the magnetic ceramic and the non-magnetic ceramic are distinguished by areas hatched with lines drawn in different directions as shown in FIG.  3 A. 
     To produce the composite green sheet  11 , a carrier film  14  fabricated of a synthetic resin such as polyethylene terephthalate, for example, is prepared as shown in FIG. 5A. A magnetic ceramic paste is printed on the carrier film  14  to form the magnetic ceramic region  12 . 
     A non-magnetic ceramic paste is then printed on the carrier film  14  on the area other than the formation area of the magnetic ceramic region  12  to form the non-magnetic ceramic region  13  (see FIG.  5 C). 
     In this way, a third transfer member  15  in this preferred embodiment of the present invention is prepared and includes the composite green sheet  11  on the carrier film  14 . 
     A conductor-attached composite green sheet  21  shown in FIG. 3B is preferably produced in a similar fashion. In the conductor-attached composite green sheet  21 , a conductor  22  forming a portion of the coil  9  is produced by printing an electrically conductive paste on the composite green sheet  11 . The external end of the conductor  22  defines the top lead-out portion  9   a.    
     The method of manufacturing the conductor-attached composite green sheet  21  will now be described, referring to FIGS. 6A-6D. 
     A first carrier film  23  is prepared as shown in FIG. 6A. A magnetic ceramic paste and a non-magnetic ceramic paste are successively printed on the first carrier film  23  to form a magnetic ceramic region  24  and a non-magnetic ceramic region  25 . In this way, a composite green sheet is produced. An electrically conductive paste is printed on the top surface of the composite green sheet, specifically on the top surface of the non-magnetic ceramic region  25  to form a conductor  22 . 
     A first transfer member  26  is thus obtained as shown in FIG.  6 D. 
     The conductor  22  has a via hole electrode  27  on the inner end thereof in the first transfer member  26 . The via hole electrode  27  is formed by opening a through hole using a laser or through punching, and by printing the conductive paste during the formation of the conductor  22  so that the conductive paste fills the through hole. 
     A conductor-attached composite green sheet  31  shown in FIG. 3C is produced in a similar fashion. Referring to FIG. 7A, a composite green sheet  32  is formed on a carrier film (not shown) similar to the composite green sheets  11  and  21 . Also shown in FIG. 3C are a magnetic ceramic region  33  and a non-magnetic ceramic region  34 . 
     In the composite green sheet  32 , a through hole is opened at a location where a via hole electrode is to be formed. A conductive paste is then printed on the top surface of the composite green sheet  32 . During the printing operation, the conductive paste fills the through hole. As shown in FIGS. 7B and 7C, a conductor  35  is electrically connected to a via hole electrode  36  that fills the through hole  32   a.    
     A conductor-attached composite green sheet  41  shown in FIG. 3D preferably has a construction similar to that of the conductor-attached composite green sheet  31 . The conductor-attached composite green sheets  31  and  41  define one turn of coil with the conductors  35  and  45  connected. By repeatedly laminating the conductor-attached composite green sheets  31  and  41 , a coil having a desired number of turns is produced. 
     A conductor-attached composite green sheet  51  shown in FIG. 3E has a conductor  52  having a bottom lead-out portion  9   b  at the end thereof in the same way as the conductor-attached composite green sheet  21 . The conductor-attached composite green sheet  51  has the bottom end of the coil  9  without a via hole electrode. 
     A required number of composite green sheets  11  shown in FIG. 3F is laminated below the conductor-attached composite green sheet  51 . 
     FIGS. 4A-4F are plan views diagrammatically illustrating composite green sheets accommodating the coil  10  arranged in the lower portion of the laminated ceramic electronic component  1 . Referring to FIG. 4A, a composite green sheet  11  provided to isolate the coils  9  and  10  is laminated on the top of the lower portion. Laminated below the composite green sheet  11  are composite green sheets  61 ,  62 ,  63 ,  64 , and the composite green sheet  11  respectively shown in FIG.  4 B through FIG. 4F in that order. The conductor-attached composite green sheets  61  and  64 , respectively corresponding to the conductor-attached composite green sheets  21  and  51  used in the first coil  9 , have respectively conductors  65  and  66 . The positions of the coil lead-out portions  10   a  and  10   b  are different from the positions of the coil lead-out portions  9   a  and  9   b  in the conductor-attached composite green sheets  21  and  51 . The conductor-attached composite green sheets  62  and  63  have a construction similar to that of the conductor-attached composite green sheets  31  and  41 . 
     To produce the laminated ceramic electronic component  1  of this preferred embodiment, composite green sheets shown in FIG.  3 A through FIG. 4F are stacked into a laminate, and then a plurality of green sheets defining the external layers and made of a magnetic ceramic are stacked onto the laminate from above and from below. The resulting laminate structure is then pressed in the direction of thickness thereof, and is then sintered. The sintered ceramic body  2  shown in FIG. 1 is thus produced. The external electrodes  3  through  6  are disposed on the external surfaces of the sintered ceramic body  2 . The laminated ceramic electronic component  1  is thus produced. 
     The lamination method of the composite green sheet will now be discussed, referring to FIG.  8 A through FIG.  9 B. 
     Referring to FIG. 8A, a second transfer member  71  is prepared to produce the bottom external layer. The second transfer member  71  includes a substantially rectangular magnetic ceramic green sheet  73  arranged on a second carrier film  72 . 
     Referring to FIG. 8B, the second transfer member  71  is pressed with the side of the magnetic ceramic green sheet  73  against a flat lamination stage  74 . The second carrier film  72  is then peeled off from the magnetic ceramic green sheet  73 . In this way, the magnetic ceramic green sheet  73  is transferred to the lamination stage  74  from the second transfer member  71 . 
     By repeating the above step, a plurality of magnetic ceramic green sheets  73  are laminated as shown in FIG.  8 C. The composite green sheets  11  shown in FIG. 4F are laminated in the same transfer method. The composite green sheet  11  is supported on the carrier film  14 , thereby forming the third transfer member  15 . The third transfer member  15  is laminated with the composite green sheet  11  pressed onto the already laminated magnetic ceramic green sheet  73  as shown in FIG. 8C, and the carrier film  14  is peeled off. In this way, the composite green sheet  11  is transferred from the third transfer member  15 . 
     Referring to FIG. 9A, the conductor-attached composite green sheet  51  is laminated in the same transfer method. Specifically, a first transfer member  78  having a conductor-attached composite green sheet  51  supported by a first carrier film  77  is prepared. The first transfer member  78  is laminated with the conductor-attached composite green sheet  51  pressed on the already laminated composite green sheet  11 . The first carrier film  77  is then peeled off. The conductor-attached composite green sheet  51  is laminated in this way. Referring to FIG. 9B, a conductor-attached composite green sheet  41  is also laminated through the same transfer method. Through these steps, a laminate for the above-referenced sintered ceramic body  2  is obtained. 
     In the manufacturing method of the laminated ceramic electronic component  1  of this embodiment, the transfer member having the composite green sheet or the conductor-attached composite green sheet supported on the carrier film is prepared. The composite green sheets and the conductor-attached composite green sheet are successively laminated. The laminate structure for the sintered ceramic body  2  is thus obtained. 
     FIG. 10 is a perspective view showing a chip type monolithic common-mode choke coil as a laminated ceramic electronic component of a second preferred embodiment of the present invention. FIGS. 11A and 11B are sectional views of the laminated ceramic electronic component, respectively taken along line A—A and line B—B in FIG.  10 . 
     A laminated ceramic electronic component  101  includes a sintered ceramic body  102 . In the second preferred embodiment as well, first and second coils  9  and  10  are arranged in the top portion and the bottom portion of the sintered ceramic body  102 . Similar to the sintered ceramic body  2 , the sintered ceramic body  102  is constructed of a magnetic ceramic  103  and a non-magnetic ceramic  104 . The coil portions of the coils  9  and  10  are enclosed in the non-magnetic ceramic  104 . 
     The second preferred embodiment is different from the first preferred embodiment in that the non-magnetic ceramic  104  is provided in the regions of the coil portions of the coils  9  and  10 , and is not provided in the regions of the lead-out portions  9   a,    9   b,    10   a,  and  10   b.  The rest of the laminated ceramic electronic component  101  of the second embodiment is preferably identical to that of the laminated ceramic electronic component  1  of the first preferred embodiment. 
     The sintered ceramic body  102  is produced by laminating sheets shown in FIGS. 12A-12D, FIGS. 13A and 13B, and FIGS. 14A-14D and by sintering the resulting laminate. 
     External layers are provided in the top portion and the bottom portion of the laminated ceramic electronic component  101  by laminating a desired number of substantially rectangular magnetic ceramic green sheets  111  shown in FIG.  12 A. 
     To produce the top coil  9 , a conductor-attached green sheet  112  shown in FIG. 12B, a conductor-attached green sheet  113  shown in FIG. 12C, and a conductor-attached green sheet  114  shown in FIG. 12D are laminated in that order from top to bottom. The conductor-attached green sheet  112  includes a magnetic ceramic region  116  and a non-magnetic ceramic region. The non-magnetic ceramic region, although not shown in FIG. 12B, is formed below a conductor  118 . A via hole electrode is arranged at the inner end of the conductor  118 . The via hole electrode is formed by opening a through hole in the ceramic green sheet using a laser or through punching, and by filling the through hole with an electrically conductive paste preferably made of the same material as that of the conductor  118 . 
     The conductor-attached green sheet  113  shown in FIG. 12C includes a substantially rectangular non-magnetic ceramic region  119  located at an area of the coil portion in a substantially rectangular frame outline and a magnetic ceramic region  120  located in the remaining area. A conductor  121  is formed by printing an electrically conductive paste in a half turn portion of the non-magnetic ceramic region  119  in the substantially rectangular frame outline. The conductor  121  has a via hole electrode at one end  121   a  thereof. 
     Like the conductor-attached green sheet  113 , the conductor-attached green sheet  114  shown in FIG. 12D includes a substantially rectangular outline non-magnetic ceramic region  119 . A conductor  122  is connected to the conductor  121 , thereby forming one turn of the coil. The conductor  122  overlaps only the end of the conductor  121 . 
     By laminating alternately conductor-attached green sheets  113  and  114 , the coil  9  having a desired number of turns is produced. 
     Arranged beneath the conductor-attached green sheet  114  is a composite green sheet  123  shown in FIG.  13 A. The composite green sheet  123  preferably includes a substantially rectangularly outlined non-magnetic ceramic region  125  and a magnetic ceramic region  124  located in the remaining area of the composite green sheet  123 . A conductor  126  having a coil lead-out portion  9   b  is printed to overlap the non-magnetic ceramic region  125  by a half turn. The inner end of the conductor  126  is electrically connected to a via hole electrode of the conductor-attached composite green sheet laminated above. The composite green sheet  123  thus has no via hole electrode. 
     Arranged beneath the conductor-attached composite green sheet  123  are a desired number of composite green sheets  131  shown in FIG.  13 B. The composite green sheet  131  includes a substantially rectangularly outlined non-magnetic ceramic region  133  and a magnetic ceramic region  132  located in the remaining area of the composite green sheet  131 . The composite green sheet  131  is arranged to isolate the lower coil  10  from the upper coil  9 . 
     FIGS. 14A-14D are plan views respectively showing composite green sheets used in a laminate forming a coil  10 . A composite green sheet  141  has a construction that is preferably identical to that of the conductor-attached composite green sheet  123  except for the position of the coil lead-out portion thereof. Specifically, a conductor  142  has a lead-out portion  10   a  of the coil  10 . 
     Conductor-attached composite green sheets  143  and  144  respectively shown in FIGS. 14B and 14C respectively preferably have the same constructions as those of the conductor-attached green sheets  113  and  114  forming the coil  9 . A conductor-attached composite green sheet  145  shown in FIG. 14D has a construction that is substantially identical to that of the conductor-attached green sheet  112  arranged above the coil  9 . Specifically, a conductor  146  has a lead-out portion  10   b  of the coil  10 . 
     The above-described composite green sheets are laminated through the same transfer method described in connection with the first preferred embodiment, and the magnetic ceramic green sheets  111  are laminated above and below the laminate through the transfer method. The resulting laminate structure is pressed in the direction of thickness, and is then sintered. The sintered ceramic body  102  of the second preferred embodiment is thus produced. 
     Each of the sintered ceramic bodies  2  and  102  of the first and second preferred embodiments is preferably provided with the four external electrodes. Alternatively, a laminated ceramic electronic component  151 , as a modification of the first and second preferred embodiments, preferably includes six or more external electrodes  153 - 158  on the external surface of a sintered ceramic body  152 . In this case, as shown in FIGS. 16A and 16B, the sintered ceramic body  152  includes three coils arranged in the direction of thickness in the same way as in the first and second preferred embodiments. 
     In the present invention, the number of coils and the number of internal electrodes, arranged within the sintered ceramic body, are not limited to any particular numbers. 
     FIG. 17 is a perspective view showing the external appearance of a laminated ceramic electronic component  201  according to a third preferred embodiment of the present invention. FIGS. 18A-18C are sectional views of the laminated ceramic electronic component  201 , respectively taken along line A—A, line B—B, and line C—C in FIG.  17 . As in the first and second preferred embodiments, in the laminated ceramic electronic component  201  of the third preferred embodiment, a sintered ceramic body  202  is preferably made of a magnetic ceramic  203  and a non-magnetic ceramic  204 . The sintered ceramic body  202  accommodates first and second coils  9  and  10  therein. The coil  9  includes a coil portion where a conductor thereof is coiled, and first and second lead-out portions  9   a  and  9   b.  The coil  10  also includes a coil portion where a conductor thereof is coiled, and first and second lead-out portions  10   a  and  10   b.  The non-magnetic ceramic  204  is different from its counterpart in the second preferred embodiment. In the laminated ceramic electronic component  1  of the second preferred embodiment, non-magnetic ceramic layers are not provided above and below each of the coil lead-out portions  9   a  and  9   b  of the coil  9  and the coil lead-out portions  10   a  and  10   b  of the coil  10 . In the third preferred embodiment, each of the coil lead-out portions  9   a  and  10   a  is sandwiched between non-magnetic ceramic layers  204   a  and each of the coil lead-out portions  9   b  and  10   b  is sandwiched between non-magnetic ceramic layers  204   b.  The rest of the construction of the third preferred embodiment is preferably the same as that of the second preferred embodiment. Like components are designated with like reference numerals, and repetitious discussion of these elements is omitted. 
     By enclosing the coil lead-out portions  9   a,    9   b,    10   a,  and  10   b  in the non-magnetic ceramic layers  204   a  and  204   b,  normal impedance is reduced. 
     Since the coil lead-out portions  9   a,    9   b,    10   a,  and  10   b  are also enclosed in the non-magnetic ceramic in the first preferred embodiment, the first preferred embodiment also provides the advantage of a low normal impedance. 
     FIG. 19 is a perspective view showing the external appearance of a laminated ceramic electronic component  251  of a fourth preferred embodiment of the present invention, and FIGS. 20A-20C are sectional views of the laminated ceramic electronic component, respectively taken along line A—A, line B—B, and line C—C in FIG.  19 . 
     As in the third preferred embodiment, the laminated ceramic electronic component  251  of the fourth preferred embodiment includes coil lead-out portions  9   a  and  9   b  of a coil  9  and coil lead-out portions  10   a  and  10   b  of a coil  10  enclosed in non-magnetic ceramic layers  204   c  and  204   d.  As seen from FIG. 20C, the non-magnetic ceramic layers  204   c  and  204   d  enclosing the coil lead-out portions  9   a  and  10   a  extend along the full width of a sintered ceramic body  252  at respective levels. In the third preferred embodiment, a portion surrounding the coil lead-out portions  9   a  and  10   a  is formed of the non-magnetic ceramic layers  204   a  and  204   b.  In the fourth preferred embodiment, the non-magnetic ceramic layers  204   c  and  204   d  extend along the full width of the sintered ceramic body  252  in the coil lead regions. 
     FIG. 21 is a perspective view showing the external appearance of a laminated ceramic electronic component  301  of a fifth preferred embodiment of the present invention, and FIGS. 22A-22C are sectional views of the laminated ceramic electronic component, respectively taken along line A—A, line B—B, and line C—C in FIG.  21 . 
     Referring to FIG. 22A, in the laminated ceramic electronic component  301  of the fifth preferred embodiment, a sintered ceramic body  302  preferably includes a magnetic ceramic  303  and non-magnetic ceramics  304 . The non-magnetic ceramics  304  extend outwardly from the coil portions of the coils  9  and  10  in the longitudinal direction of the sintered ceramic body  302 . In other words, the sintered ceramic body  302  includes the magnetic ceramic  303  in the center thereof, and the non-magnetic ceramics  304  in both longitudinal end portions thereof. The non-magnetic ceramics  304  inwardly extend from the longitudinal end portions of the sintered ceramic body  302  to cover the coil portions of the coils  9  and  10 . Therefore, the coil lead-out portions  9   a,    9   b,    10   a,  and  10   b  of the coils  9  and  10  are enclosed in the non-magnetic ceramics  304 . The longitudinal end portions of the sintered ceramic body  302  are thus fully formed of the non-magnetic ceramics  304 . The rest of the construction of the fifth preferred embodiment is substantially the same as that of the second preferred embodiment. 
     Since the non-magnetic ceramics  304  fully coat the coil lead-out portions  9   a,    9   b,    10   a,  and  10   b  in the laminated ceramic electronic component  301  of the fifth preferred embodiment, high-frequency characteristics and normal impedance of the laminated ceramic electronic component  301  are greatly improved. 
     FIG. 23 is an elevational sectional view of a laminated ceramic electronic component  401  of a sixth preferred embodiment of the present invention. 
     In the laminated ceramic electronic component  401 , a sintered ceramic body  402  includes a coil  403 . The top end of the coil  403  is routed out to an end surface  402   a  of the sintered ceramic body  402 , while the bottom end of the coil  403  is routed out to the other end surface  402   b.  As in the first preferred embodiment through fifth preferred embodiment, the coil  403  is enclosed in the non-magnetic ceramic  405 , and the remaining portion of the laminated ceramic electronic component  401  is made of a magnetic ceramic  406 . A non-magnetic ceramic layer  407  fully horizontally extends at a level within the sintered ceramic body  402  between an upper portion  403   a  and a lower portion  403   b  of the coil  403 . 
     External electrodes  408  and  409  are arranged, respectively, to cover end surfaces  402   a  and  402   b.  The external electrodes  408  and  409  are electrically connected to the top end and the bottom end of the coil  403 . The laminated ceramic electronic component  401  of the sixth preferred embodiment is also manufactured preferably in the same manner as those of the first through fifth preferred embodiments. Specifically, the conductor-attached composite green sheets are laminated through the transfer method, the magnetic green sheets are stacked onto the laminate from above and below, and the resulting laminate structure is then sintered. Like the laminated ceramic electronic component  1  of the first preferred embodiment, the laminated ceramic electronic component  401  of the sixth preferred embodiment is manufactured through relatively simple steps at low costs, compared with conventional monolithic inductors. When the conductor is printed, printing accuracy of the electrically conductive paste is high because the top surface of the composite green sheet is flat. 
     Since the laminated ceramic electronic component  401  of the sixth preferred embodiment includes the non-magnetic ceramic layer  407  located between the top portion  403   a  and the bottom portion  403   b  of the coil  403 , an open magnetic circuit type inductor is provided. The generation of a magnetic flux between coil conductors at each level of the coil  403  is controlled. Furthermore, the generation of a magnetic flux running between the top portion  403   a  and the bottom portion  403   b  is controlled. This arrangement results in a monolithic inductor that is excellent in current superimposition characteristics and is much less susceptible to a reduction in inductance value. 
     FIG. 24 is an elevation sectional view of a modification of the laminated ceramic electronic component  401  of the sixth preferred embodiment shown in FIG.  23 . The laminated ceramic electronic component  401  includes the non-magnetic ceramic layer  407  fully extending along the horizontal section at a middle level within the sintered ceramic body  402 . As shown in FIG. 24, a non-magnetic ceramic layer  407 A extends only within a region in which a coil  403  is wound. In this case, an open magnetic circuit type inductor results. 
     FIG. 25 is an elevational sectional view showing yet another modification of the laminated ceramic electronic component  401 . In a laminated inductor  421  shown in FIG. 25, a non-magnetic ceramic layer  407 B is arranged externally relative to a region in which a coil  403  is wound. In this case as well, an open magnetic circuit type inductor results. 
     To control a large magnetic flux running between the top and bottom portions  403   a  and  403   b  of the coil, each of the non-magnetic ceramic layers  407 ,  407 A, and  407 B is arranged in a place where the magnetic flux needs to be blocked. The position of the non-magnetic ceramic layer is not limited to specific preferred embodiments and the modifications thereof described above. 
     In accordance with the method of various preferred embodiments of the present invention of manufacturing the laminated ceramic electronic component, the first and second transfer members are prepared, and are subjected to the first through third transfer steps. The laminated ceramic body is thus produced. Compared with the lamination-by-printing method that repeats printing, the steps are simplified, and costs of the laminated ceramic electronic component are greatly reduced. 
     In the lamination-by-printing method, the flatness of the surface of the underlayer is not sufficient, and the pastes run and migrate. The ceramic component suffers from variations in performance. In accordance with various preferred embodiments of the present invention, the underlayer on which the conductor is printed is flat. Since the conductor-attached composite green sheets and the ceramic green sheet are laminated through the transfer method. A laminated ceramic electronic component that is reliable and suffers from less performance variations is thus provided. 
     The via hole electrode is formed in the composite ceramic green sheet in at least one first transfer member to connect the conductors of the conductor-attached composite green sheets. A plurality of conductors are electrically connected through the via holes. A coil conductor functioning as an inductor is thus easily produced. 
     The first ceramic region is preferably made of the magnetic ceramic, and the second ceramic region is preferably made of the non-magnetic ceramic. By arranging a conductor forming a coil in the non-magnetic ceramic region, an open magnetic circuit type laminated coil is easily provided. 
     When the ceramic green sheet of the second transfer member is made of the magnetic ceramic, the top and bottom external layers of the laminated ceramic electronic component are preferably made of the magnetic ceramic. 
     The first ceramic region and the second ceramic region are formed by respectively printing the magnetic ceramic paste and the non-magnetic ceramic paste. Since the first and second ceramic regions do not overlap each other, a composite ceramic green sheet having a flat top surface is easily produced. 
     The via hole electrode is produced by keeping the first and second ceramic regions out of a via hole electrode formation area when the composite ceramic green sheet is produced, and then by filling the via hole electrode formation area with an electrically conductive paste. In this way, the via hole electrode having a highly reliable electrical connection is provided. 
     The via hole electrode is produced by opening a through hole in a via hole electrode formation area subsequent to the production of the composite ceramic green sheet, and then by filling the through hole with an electrically conductive paste. The via hole electrode formation step is simplified. Since the filling step of filling the through hole with the electrically conductive paste is performed concurrently together with the printing step of printing the conductor, the steps are substantially simplified. 
     When the ceramic green sheet of the second transfer member is produced by forming the ceramic green sheet on the second carrier film, a known ceramic green sheet formation technique such as a doctor blading technique may be used. 
     The third transfer member that includes the composite ceramic green, and the third carrier film supporting the composite ceramic green sheet, is prepared. The composite ceramic green sheet is transferred from at least one third transfer member between the first transfer step and the third transfer step. One of the first ceramic region and the second ceramic region is formed to be in contact with the conductor such as the coil from above or below. 
     The laminated ceramic electronic component of other preferred embodiments of the present invention is produced by the manufacturing method of the above-described preferred embodiments of the present invention of the laminated ceramic electronic component. In the laminated ceramic electronic component having the first and second ceramic regions in the sintered ceramic body, the laminated ceramic electronic component having a variety of functions such as an open magnetic circuit type laminated coil may be produced by selecting the materials of the first and second ceramic regions. 
     In the laminated ceramic electronic component according to preferred embodiments of the present invention, not only the coil portion of the coil but also the first and second coil lead-out portions are encapsulated in the non-magnetic ceramic. When the component is used as a monolithic inductor, normal impedance thereof is greatly reduced. 
     While preferred embodiments of the invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing the scope and spirit of the invention. The scope of the invention, therefore, is to be determined solely by the following claims.