Abstract:
Provided is a method for manufacturing a film-formed body wherein a second film is formed by suppressing influence of existence/absence of a first film, at the time of forming the second film by making fine particles collide and deposited on a second film forming surface on a substrate whereupon the first film has been already formed. A film-formed body is provided with a foil-like substrate having a first film-forming surface and a second film-forming surface; a first film formed on a part of the first film-forming surface; and a second film formed at least on a part of the second film-forming surface. The first film includes an overlapping section which overlaps with the second film when viewed in the thickness direction of the substrate. A method for manufacturing such film-formed body is provided with a second film-forming step of forming the second film on the second film-forming surface whereupon the first film has been formed, by making the fine particles collide and deposited on the second film-forming surface, by using a supporting member having a supporting surface and a recessed section depressed from the supporting surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation application based upon and claims the benefit of the prior PCT International Patent Application No. PCT/JP2009/060218 filed on Jun. 4, 2009, the entire contents of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD  
       [0002]    The present invention relates to a method for manufacturing a film-formed body including a foil-like substrate (base body) and a film or layer formed on a film-forming surface thereof. 
       BACKGROUND ART  
       [0003]    As a technique for forming a film or layer having a thickness less than about several hundreds μm on a substrate, an aerosol deposition method has been known. This aerosol deposition method is a technique for forming a film made of microparticles by stirring up raw microparticles in air by for example gas supply, vibration, ultrasonic vibration, etc., thereby dispersing (mixing) the microparticles in carrier gas for aerosolization, making this collide and deposited. 
         [0004]    Patent Literature 1 discloses a technique for forming a composite structure (a film) simultaneously or sequentially on both surfaces of a film-like base material (substrate) by using the aerosol deposition method. 
       Citation List 
     Patent Literature 
       [0005]    Patent Literature 1: JP 2004-300572 A 
       SUMMARY OF INVENTION  
     Technical Problem 
       [0006]    However, some consideration is given to the case in which a foil-like substrate having a first film-forming surface on which a first film has already been formed is to be formed with a second film on a second film-forming surface which is a back surface of the first film-forming surface of the substrate by the technique of Patent Literature 1. In this case, the second film-forming surface have a difference in ease of forming the second film between an overlapping portion which overlaps the first film through the substrate and other portions due to the influence of the thickness of the first film. This may cause such defects in the second film as non-uniform thickness and occurrence of a step or shoulder on or near a boundary area. 
         [0007]    The present invention has been made in view of the circumstances to solve the above problems and has a purpose to provide a method for manufacturing a film-formed body in such a manner that a second film is formed on a second film-forming surface which is a back surface of a substrate whose first film-forming surface has already been formed with a first film, by making microparticles collide and be deposited on the second film-forming surface while suppressing the influence of existence/absence of the first film. 
       Solution to Problem 
       [0008]    To achieve the above object, one aspect of the invention provides a method for manufacturing a film-formed body comprising: a foil-like substrate having a first film-forming surface and a second film-forming surface which is a back side of the first film-forming surface; a first film formed on a part of the first film-forming surface of the substrate; and a second film formed on at least part of the second film-forming surface of the substrate, the first film including an overlapping portion that overlaps with the second film when viewed in a thickness direction of the substrate, the method comprising: a second film-forming step of forming the second film by making microparticles collide with and be deposited on the second film-forming surface of the substrate on which the first film has been formed, wherein the second film-forming step including forming the second film by using a support member having a support surface and a recess depressed lower than the support surface, when a region of the second film-forming surface of the substrate, with which the microparticles are made to collide to form the second film, is referred to as a second film forming region, a film-forming overlap region of the overlapping portion of the first film, which overlaps with at least the second film forming region when viewed in the thickness direction of the substrate, is placed in the recess of the support member. 
         [0009]    In the above film-formed body manufacturing method, in the second film-forming step of forming the second film on the second film-forming surface which is a back surface of the substrate on which the first film has already been formed, the film-forming overlap region of the overlapping portion of the first film is placed in the recess of the support member and the second film is formed. 
         [0010]    Specifically, the second film is formed on the second film-forming surface while at least part of the first film in the thickness direction is placed in the recess depressed lower than the support surface. This makes it possible to reduce the influence of the thickness of the first film as compared with the case where the first film is not placed in the recess. Thus, the second film can be formed appropriately by preventing such defects that the thickness of the second film differs from portion to portion depending on the presence/absence of the first film on the surface and a step occurs. 
         [0011]    The first film can be produced by any method not particularly limited. Accordingly, the same method as for the second film may be used but another method such as plating, coating, and sputtering may be used. 
         [0012]    The method of forming the second film is a technique for forming the second film by making microparticles collide with and be deposited on the substrate. There are some examples such as an aerosol deposition method in which microparticles are raised or stirred up in gas such as air and blown against the substrate, causing the microparticles to collide and be deposited thereon, thereby forming the second film, a gas deposition method in which a raw material is evaporated and vaporized and then precipitated in the form of nanoparticles in gas phase, and the precipitated nanoparticles are dispersed in carrier gas and caused to collide with a substrate to form the second film. Furthermore, other alternatives may include thermal spraying, cold spraying, etc. In the case of a foil-like substrate, the aerosol deposition method and the gas deposition method are preferably adopted because aerosols or nanoparticles collide against the substrate at lower collision speeds than that in the thermal spraying and the cold spraying. 
         [0013]    The foil-like substrate may have an appropriate shape such as a rectangular shape having a predetermined size and a long strip shape. Accordingly, as well as the case where the substrates each having a predetermined size are simultaneously subjected to the second film-forming step, a long substrate may be sequentially or continuously formed with second films from one end to the other end by movement in the longitudinal direction. In this case where a portion to be formed with the second film is moved for continuous formation, the second film forming region is also moved on the substrate with time. 
         [0014]    The support member may be an integral member formed with a recess but may be constituted of a plurality of members. For example, it may be arranged that a member formed with a through hole in only a portion corresponding to the recess is placed on a base member to provide the support surface and the recess. The support surface is formed in the support member and defines a plane facing the substrate (or its first film-forming surface) (a substrate facing plane). This support surface may contact or may not contact with the substrate. 
         [0015]    In the above film-formed body manufacturing method, preferably, the second film-forming step including placing a film-forming non-overlap region of a first exposed portion of the first film-forming surface on the support surface of the support member, the film-forming non-overlap region overlapping at least the second film forming region when viewed in the thickness direction of the substrate and the first exposed portion being exposed without being formed with the first film. 
         [0016]    In the above film-formed body manufacturing method, in the second film-forming step of forming the second film on the second film-forming surface which is the back side of the substrate on which the first film has already been formed, the film-forming overlap region of the overlapping portion of the first film is placed in the recess of the support member, the film-forming non-overlap region of the first exposed portion of the first film-forming surface is placed on the support surface of the support member, and the second film is formed. This can reliably prevent such defects that the thickness of the second film differs from portion to portion and a step occurs. 
         [0017]    In a method for manufacturing a film-formed body comprising: a foil-like substrate having a first film-forming surface and a second film-forming surface which is a back side of the first film-forming surface; a first film formed on a part of the first film-forming surface of the substrate; and a second film formed on at least part of the second film-forming surface of the substrate, the first film including an overlapping portion that overlaps with the second film when viewed in a thickness direction of the substrate, preferably, the method comprises: a second film-forming step of forming the second film by making microparticles collide with and be deposited on the second film-forming surface of the substrate on which the first film has been formed, wherein the second film-forming step including forming the second film by using a support member having a support surface and a recess depressed lower than the support surface, and the second film-forming step including forming the second film while holding the overlapping portion of the first film in the recess of the support member and holding a first exposed portion of the first film-forming surface, the first exposed portion being not formed with the first film, on the support surface of the support member. 
         [0018]    In this film-formed body manufacturing method, in the second film-forming step of forming the second film on the second film-forming surface of the substrate in which the first film has already been formed on the first film-forming surface, the second film is formed while the overlapping portion of the first film is placed in the recess of the support member and also the first exposed portion of the first film-forming surface is placed on the support surface of the support member. 
         [0019]    This can reduce the influence of presence/absence of the first film as compared with the case where the overlapping portion of the first film is not placed in the recess. 
         [0020]    The substrate may include for example a configuration that enables simultaneous formation of second films on a substrate held at rest with respect to the substrate. 
         [0021]    In the above film-formed body manufacturing method, preferably, the recess of the support member has a depth larger than thickness of the first film, the second film-forming step includes forming the second film while holding the film-forming non-overlap region on the support surface of the support member. 
         [0022]    If the depth of the recess of the support member is smaller than the thickness of the first film, a part of the first film in the thickness direction protrudes from the recess. Accordingly, the substrate (the first film-forming surface) is liable to separate from and come out of contact with the support surface around the first film. 
         [0023]    In this case, the second film-forming surface includes a portion whose back side (the first film-forming surface side) contacts with the support surface and a portion whose back side does not contact with the support surface. Thus, the ease of forming the second film, the thickness, and the property of the second film may differ according to the portions. 
         [0024]    According to the aforementioned film-formed body manufacturing method, on the other hand, the depth of the recess is larger than the thickness of the first film, so that the whole first film in the thickness direction can be received (placed) in the recess. Also, the film-forming non-overlap region is supported by the support surface of the support member. This can prevent the substrate from separating from the support surface around the first film and also avoid a difference in the ease of forming the second film due to the separation. 
         [0025]    Alternatively, in the above film-formed body manufacturing method, preferably, the recess of the support member has a depth less than or equal to the thickness of the first film, the support surface of the support member and a bottom surface of the recess have different hardnesses, the hardnesses are determined such that a difference in thickness between a portion of the second film overlapping with the film-forming overlap region and a portion of the second film overlapping with the film-forming non-overlap region when viewed in the thickness direction of the substrate is smaller than that when the second film is formed in the second film-forming step in the case where the support surface and the bottom surface of the recess have the same hardness. 
         [0026]    In the portion overlapping with the film-forming overlap region in the second film-forming surface, the first film and the substrate are present between the second film and the bottom surface of the recess of the support member. On the other hand, in the portion overlapping with the film-forming non-overlap region in the second film-forming surface, only the substrate is present between the second film and the support surface of the support member, that is, it is different in the presence/absence of the first film. For instance, therefore, the influence of impact on the microparticles is different between a case where the support surface and the bottom surface of the recess of the support member are made of the same material (e.g., the same metal material) and with the same hardness and the microparticles are made to collide and be deposited on the film-forming overlap region and a case where microparticles are made to collide and be deposited on the film-forming non-overlap region. This may result in the second films formed with different thickness. 
         [0027]    In the aforementioned film-formed body manufacturing method, on the other hand, the support surface and the bottom surface of the recess of the support member are designed to be different in hardness. This can prevent such defects that the thickness of the second film differs between the film-forming overlap region and the film-forming non-overlap region due to the influence of hardness of both surfaces. 
         [0028]    A method for providing different hardness between the support surface and the bottom surface of the recess may be achieved by for example forming a film identical to the first film or a film made of a different material from the first film but with the same hardness on the support surface, thereby providing different hardness between the support surface and the bottom surface of the recess. 
         [0029]    In the above film-formed body manufacturing method, preferably, the support surface is formed of a film made of the same material and with the same thickness as the first film. 
         [0030]    In the aforementioned film-formed body manufacturing method, the support surface of the support member is made of the same material and further with the same thickness as the first film. Accordingly, when the substrate on which the first film has been formed is to be supported by the support member, the first film contacting with the substrate in the film-forming overlap region can be the same in material and thickness as the film of the support surface with which the substrate in the film-forming non-overlap region contacts. In other words, the ease of forming the second film can be uniform between a portion overlapping with the film-forming overlap region and a portion overlapping with the film-forming non-overlap region in the second film-forming surface. Thus, the second film can be formed with uniform thickness and quality over the second film-forming surface of the substrate. 
         [0031]    In one of the above film-formed body manufacturing methods, preferably, the second film-forming step adopts an aerosol deposition method or a gas deposition method. 
         [0032]    In the aforementioned film-formed body manufacturing method, the second film-forming step adopts the aerosol deposition method or the gas deposition method. For example, the collision speed of aerosols or nanoparticles can be made lower than that in the case of using thermal spraying or cold spraying, so that film formation can be achieved without deforming the foil-like substrate. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0033]      FIG. 1  is a perspective view of a film-formed body in a first embodiment and a first modified example; 
           [0034]      FIG. 2  is a sectional view (section A-A in  FIG. 1  and section C-C in  FIG. 12 ) of the film-formed body in the first embodiment, a second embodiment, and the first modified example; 
           [0035]      FIG. 3  is a top view of the film-formed body in the first embodiment and the first modified example; 
           [0036]      FIG. 4  is an explanatory view of a power generating element of a bipolar secondary battery; 
           [0037]      FIG. 5  is an explanatory view of a first film-forming step for the film-formed body in the first embodiment; 
           [0038]      FIG. 6  is an explanatory view of a second film-forming step for the film-formed body in the first embodiment; 
           [0039]      FIG. 7  is an explanatory view of a second film-forming step for the film-formed body in the first embodiment and the first modified example; 
           [0040]      FIG. 8  is an explanatory view of the second film-forming step for the film-formed body in the first embodiment; 
           [0041]      FIG. 9  is an explanatory view of the second film-forming step for the film-formed body in the first embodiment; 
           [0042]      FIG. 10  is an explanatory view of the second film-forming step for the film-formed body in the first modified example; 
           [0043]      FIG. 11  is an explanatory view of the second film-forming step for the film-formed body in the first modified example: 
           [0044]      FIG. 12  is a perspective view of the film-formed body in the second modified example; 
           [0045]      FIG. 13  is a top view of the film-formed body in the second modified example; 
           [0046]      FIG. 14  is an explanatory view of a manufacturing step for the film-formed body in the second embodiment; 
           [0047]      FIG. 15  is another explanatory view of the manufacturing step for the film-formed body in the second embodiment; 
           [0048]      FIG. 16  is another explanatory view of the manufacturing step for the film-formed body in the second embodiment; 
           [0049]      FIG. 17  is another explanatory view of the manufacturing step for the film-formed body in the second embodiment; and 
           [0050]      FIG. 18  is another explanatory view of the manufacturing step for the film-formed body in the second embodiment. 
       
    
    
     REFERENCE SIGNS LIST  
       [0000]    
       
           1 ,  101  Film-formed body 
           11 ,  111  First film 
           12 ,  112  Second film 
           20 ,  120  Metal foil (Substrate) 
           21 ,  121  First metal principal surface (First film-forming surface) 
           21 F,  121 F First exposed portion (First exposed portion) 
           22 ,  122  Second metal principal surface (Second film-forming surface) 
           53 ,  153  Metal foil support member (Support member) 
           55 ,  155 ,  255  Support surface 
           56 ,  156 ,  256  Recess 
           56 D,  156 D,  256 D Bottom surface (of Recess) 
           253  Second backup roll member (Support member) 
         D 2  Second mixed microparticles (Microparticles) 
         D 3  Third microparticles (Microparticles) 
         DT Thickness direction (of metal foil) 
         F 1 , F 2 , F 3  Depth (of Recess) 
         LW Overlapping portion (of first film) 
         R Second-film forming region 
         RW Film-forming overlap region 
         RX Film-forming non-overlap region 
         SF 1 , SF 2  Film 
         TS Film thickness (Thickness) (of film SF) 
       
     
       DESCRIPTION OF EMBODIMENTS  
     First Embodiment  
       [0073]    A detailed description of a first preferred embodiment of the present invention will now be given referring to the accompanying drawings. 
         [0074]    A film-formed body  1  of the first embodiment will be first explained.  FIG. 1  is a perspective view of the film-formed body  1  and  FIG. 2  is a sectional view (section A-A in  FIG. 1 ) of the film-formed body  1 . 
         [0075]    The film-formed body  1  of the first embodiment includes a rectangular metal foil  20  made of stainless steel, a first film (layer)  11  containing a mixture of lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), and a second film (layer)  12  containing a mixture of lithium cobalt oxide (LiCoO 2 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), and besides, a third film  13  containing phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). In this film-formed body  1 , the first film  11  is formed on a first metal principal surface  21  facing upward in  FIGS. 1 and 2 , of the metal foil  20 , and the second film  12  is formed on a second metal principal surface  22  facing downward in  FIGS. 1 and 2 , which is an opposite side to the first metal principal surface  21 , and further the third film  13  is formed on the second film  12 . 
         [0076]    As shown in the sectional view of the film-formed body  1  in  FIG. 2 , the size of the second film  12  in a lateral direction in  FIG. 2  is larger than the size of the first film  11 . When the film-formed body  1  is viewed in a thickness direction DT of the metal foil  20  (see  FIG. 3 ), the first film  11  is positioned on a frontmost side in  FIG. 3 , the metal foil  20  is located behind the first film  11 , and further the second film  12  is positioned further behind this metal foil  20  in  FIG. 3 . When the film  11  is entirely viewed in the thickness direction DT of the metal foil  20 , the first film  11  is also an overlapping portion LW that overlaps with the second film  12 . 
         [0077]    In the film-formed body  1 , the lithium titanium oxide (Li 4 Ti 5 O 12 ) of the first film  11  can be used as a negative active material of a lithium ion secondary battery. The lithium cobalt oxide of the second film  12  can be used as a positive active material of the lithium ion secondary battery. Furthermore, the phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) of the first film  11 , the second film  12 , and the third film  13  can be used as an electrolyte of the lithium ion secondary battery. 
         [0078]    Specifically, when a plurality of the above film-formed bodies  1  is laminated in the thickness direction DT, for example, a power generating element BP of a bipolar secondary battery is made up as shown in  FIG. 4 . The bipolar secondary battery refers to a battery provided with a positive electrode and a negative electrode on a single electrode plate (an electrode foil). 
         [0079]    The first film  11  of the film-formed body  1  is formed by the aerosol deposition method using a first film-forming device  40  mentioned later and the second film  12  and the third film  13  are formed by the aerosol deposition method using a second film-forming device  50  mentioned later. 
         [0080]    A manufacturing method of the film-formed body  1  in the first embodiment will be explained below with reference to the drawings. 
         [0081]      FIG. 5  is a schematic view of the first film-forming device  40  for forming the first film  11  on the metal foil  20  by the aerosol deposition method. This first film-forming device  40  includes a film forming chamber  41 , an aerosol generator  48 , a regulator  49 , a gas bomb GB, a gas pipe P 1 , and an aerosol pipe P 2 . 
         [0082]    The gas bomb GB of the first film-forming device  40  is internally filled with high-pressure argon gas used as carrier gas (not shown). This gas bomb GB feeds the carrier gas toward the aerosol generator  48  through the metal gas pipe P 1  connected to the gas bomb GB. At some point in the gas pipe P 1 , the regulator  49  is placed to regulate a flow rate of the carrier gas to be fed from the gas bomb GB. 
         [0083]    The aerosol generator  48  includes a container  48 P having a bottom-closed cylindrical shape, a closing stopper  48 Q that closes an opening this container  48 P, and an inside bottom plate  48 R having a meshed plate surface placed, like a raised bottom, at a predetermined distance from the bottom (a lower position in  FIG. 5 ) of the container  48 P. 
         [0084]    The above gas pipe P 1  and the aerosol pipe P 2  each extend passing through the closing stopper  48 Q. The gas pipe P 1  extends passing through the inside bottom plate  48 R as shown in  FIG. 5 . On the inside bottom plate  48 R facing to the stopper  48 Q, first mixed microparticles (fine particles) D 1  containing a mixture of both lithium titanium oxide (Li 4 Ti 5 O 12 ) powder and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) powder are stored. A mesh hole diameter of the plate surface of the inside bottom plate  48 R is smaller than a particle diameter of the first mixed microparticles D 1 . Accordingly, this inside bottom plate  48 R does not allow the first microparticles D 1  to pass therethrough but does allow gas, i.e., the carrier gas (not shown) to pass therethrough. The aerosol generator  48  can generate first aerosol AS 1  made of the first microparticles D 1  dispersed in the carrier gas. 
         [0085]    The film forming chamber  41  includes a metal foil support member  43  for holding the metal foil  20  while exposing the first metal principal surface  21  and a single-port injection nozzle  42  for injecting the microparticles toward the exposed first metal principal surface  21  of the metal foil  20 . In this film forming chamber  41 , the metal foil support member  43  and the injection nozzle  42  are placed. By use of a vacuum pump not shown, the pressure in the chamber can be reduced to  10   −1  Pa. 
         [0086]    The metal foil support member  43  holds the metal foil  20  on a flat support surface  45  and moves in a plane direction of the metal foil  20  in  FIG. 5  to adjust the thickness of a film to be formed on the metal foil  20 . This metal foil support member  43  is arranged to place a mask  47  of a rectangular frame shape between the injection nozzle  42  and the metal foil  20  to form the first film  11  in a predetermined position on the first metal principal surface  21 . 
         [0087]    The injection nozzle  42  includes a cylindrical main part  42 J and an injection part  42 H located on a nearer side to the metal foil  20  than the main part  42 J. The injection part  42 H has a tapered shape whose diameter is smaller as closer to the metal foil  20  side and is arranged to inject aerosol through its orifice. On an opposite side from the injection part  42 H with respect to the main part  42 J, the injection nozzle  42  further includes a connection part  42 K connected to the above aerosol pipe P 2 . This injection nozzle  42  is configured to inject the first aerosol AS 1  toward the metal foil  20  by further accelerating the aerosol AS 1  through the tapered injection part  42 H (see  FIG. 5 ). 
         [0088]      FIG. 6  is a schematic view of a second film-forming device  50  for forming the second film  12 , by the aerosol deposition method, on the second metal principal surface  22  of the metal foil  20  on which the first film  11  has been formed. This second film-forming device  50  includes a film forming chamber  51 , an aerosol generator  58 , a regulator  59 , a gas bomb GB, a gas pipe P 1 , and an aerosol pipe P 2 . 
         [0089]    The gas bomb GB, the gas pipe P 1 , and the aerosol pipe P 2  in the second film-forming device  50  are identical to those in the above first film-forming device  40 . The aerosol generator  58  is also identical to the aerosol generator  48  excepting that second mixed microparticles D 2  containing a mixture of both lithium cobalt oxide powder and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) powder are stored on an inside bottom plate  58 R of the aerosol generator  58 . 
         [0090]    The film forming chamber  51  includes a metal foil support member  53  for holding the metal foil  20  while exposing the second metal principal surface  22  and a single-port injection nozzle  52  for injecting the microparticles toward the exposed second metal principal surface  22  of the metal foil  20 . In this film forming chamber  51 , the metal foil support member  53  and the injection nozzle  52  are placed. By use of a vacuum pump not shown, as with the first film-forming device  40 , the pressure in the chamber can be reduced to  10   −1  Pa. 
         [0091]    The injection nozzle  52  is configured, as in the first film-forming device  40 , to inject second aerosol AS 2  fed from the above aerosol generator  58  toward the metal foil  20  by further accelerating the aerosol AS 2  through the tapered injection part  52 H (see  FIG. 6 ). 
         [0092]    The metal foil support member  53  includes, as shown in  FIG. 7 , a holding part  54  for holding the metal foil  20  and a slide part SW for moving the metal foil  20  held in the holding part  54  in its plane direction. This metal foil support member  53  is further arranged to place a mask  57  between the injection nozzle  52  and the metal foil  20 . The mask  57  is formed with a through hole for forming the second film  12  in a predetermined position on the second metal principal surface  22 . 
         [0093]    The holding part  54  made of metal includes a recess  56  centrally located and configured to be slightly larger than the plane shape (a rectangular shape in this embodiment) of the first film  11  to receive the first film  11  and a support surface  55  located along the circumference of the recess  56  and raised by a step from the recess  56 . A bottom surface  56 D of the recess  56  is defined by an exposed part of the metal forming the holding part  54 . The depth F  1  of the recess  56  is equal to the thickness T 1  of the first film  11  formed on the metal foil  20 . Accordingly, when the metal foil  20  formed with the first film  11  is to be held by the metal foil support member  53 , the first film  11  can be received in the recess  56  so as to contact with the bottom surface  56 D. 
         [0094]    The support surface  55  of the holding part  54  is coated with a film SF 1  made of lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), as with the first film  11 . Thus, the support surface  55  has a first hardness. On the other hand, the bottom surface  56 D of the recess  56  is made of the metal forming the holding part  54  and hence has a second hardness different from the first hardness. Those first and second hardnesses are determined to prevent a difference in the ease of forming the second film  12  on the second forming surface  22 C of the second metal principal surface  22  (e.g., the reactive force the second aerosol AS 2  (the second mixed microparticles D 2 ) receives from the metal foil  20  when collides therewith) and make the ease of film-forming uniform in the plane direction. 
         [0095]    Specifically, in a portion overlapping with a film-forming overlap region RW mentioned later of the metal foil  20  formed with the first film  11 , the first film  11  and the metal foil  20  are located between the second metal principal surface  22  and the bottom surface  56 D of the recess  56 . In a portion overlapping with a film-forming non-overlap region RX mentioned later in the second metal principal surface  22 , the metal foil  20  is located between the second metal principal surface  22  and the support surface  55 . The ease of forming the second film  12  in the portion overlapping with the film-forming overlap region RW is influenced by the hardness of the first film  11 , the hardness of the metal foil  20  itself, and the second hardness of the bottom surface  56 D of the recess  56 . On the other hand, the ease of forming the second film  12  in the portion overlapping with the film-forming non-overlap region RX is influenced by the hardness of the metal foil  20  itself and the first hardness of the support surface  55 . Accordingly, the first hardness and the second hardness are determined to provide the same ease of forming the second film  12  in the portion overlapping with the film-forming overlap region RW and the portion overlapping with the film-forming non-overlap region RX in the second metal principal surface  22 . 
         [0096]    Furthermore, the support surface  55  of the metal foil support member  53  is coated with the film SF 1  made of the same material as that for the first film  11 . In addition, the thickness TS of this film SF 1  is set to be equal (TS=T 1 ) to the thickness T 1  of the first film  11 . Thus, when the metal foil support member  53  supports the metal foil  20  formed with the first film  11 , the first film  11  with which the metal foil  20  contacts in the film-forming overlap region RW and the film SF 1  with which the metal foil  20  contacts in the film-forming non-overlap region RX are made of the same material and with the same film thickness. In the first embodiment, specifically, the ease of forming the second film  12  is made uniform between the portion overlapping with the film-forming overlap region RW and the portion overlapping with the film-forming non-overlap region RX. 
         [0097]    In a second film-forming step mentioned later, consequently, the second film  12  can be formed with uniform thickness and quality over the second film-forming surface  22 C of the second metal principal surface  22 . 
         [0098]    A first film-forming step of forming the first film  11  on the metal foil  20  by using the aforementioned first film-forming device  40  will be explained referring to  FIG. 5 . 
         [0099]    To be concrete, firstly, the metal foil  20  is set on the metal foil support member  43  in the film forming chamber  41  so that the first metal principal surface  21  of the metal foil  20  faces the injection nozzle  42 . Subsequently, the mask  47  is disposed between the metal foil  20  (the first metal principal surface  21 ) and the injection nozzle  42  to allow the first aerosol AS 1  to be injected onto the first film-forming surface  21 C of the first metal principal surface  21  to form the first film  11 . Then, the film forming chamber  41  is sealingly closed and depressurized by a vacuum pump not shown to  10   2  Pa. 
         [0100]    The first microparticles D 1  are supplied on the inside bottom plate  48 R of the aerosol generator  48  and then the opening of the container  48 P is closed with the stopper  48 Q. 
         [0101]    Then, the regulator  49  placed at some point in the gas pipe P 1  is controlled to flow a predetermined flow rate of carrier gas (not shown) from the gas bomb GB. This carrier gas will flow in the aerosol generator  48  through the gas pipe P 1 . In the aerosol generator  48 , as shown in  FIG. 5 , an end port of the gas pipe P 1  is located between the inside bottom plate  48 R and the bottom of the container  48 P. Accordingly, the carrier gas flowing in through the end port of this gas pipe P 1  passes through the inside bottom plate  48 R to move to an exit, i.e., the aerosol pipe P 2  passing through the stopper  48 Q. Passage of this carrier gas causes the first microparticles D 1  to be raised or stirred up in a space between the inside bottom plate  48 R and the stopper  48 Q, thereby producing the first aerosol AS 1 . Thus, the carrier gas carries the first microparticles D 1  of a predetermined carrying quantity per unit time, which is determined by the flow rate of carrier gas. 
         [0102]    The thus produced first aerosol AS 1  is delivered to the injection nozzle  42  of the film forming chamber  41  through the aerosol pipe P 2 . 
         [0103]    The first aerosol AS 1  delivered to the injection nozzle  42  is further accelerated through the tapered injection part  42 H and injected toward the first film-forming surface  21 C of the first metal principal surface  21  of the metal foil  20 , on which the first film  11  is to be formed. Simultaneously, the metal foil support member  43  holding the metal foil  20  is moved in the plane direction DS to form the first film  11  over the entire first film-forming surface  21  C of the first metal principal surface  21 . 
         [0104]    On the first film-forming surface  21 C of the first metal principal surface  21 , consequently, the first film  11  made of the material (lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) originating from the first microparticles D 1  is formed with the thickness T 1 . 
         [0105]    The following explanation is given to the second film-forming step of forming the second film  12 , by use of the aforementioned second film-forming device  50 , on the metal foil  20  formed with the first film  11 , referring to  FIGS. 6 ,  8 , and  9 . 
         [0106]    Firstly, the metal foil  20  formed with the first film  11  is set on the metal foil support member  53  of the film forming chamber  51 . Specifically, the entire first film  11  is received in the recess  56  of the holding part  54  of the metal foil support member  53  so that the first exposed portion  21 F uncoated with the first film  11 , of the first metal principal surface  21  of the metal foil  20 , contacts with the support surface  55  (see  FIG. 6 ). In this way, the second metal principal surface  22  of the metal foil  20  is placed to face the injection nozzle  52  (see  FIG. 6 ). At that time, the second metal principal surface  22  is a flat surface having no steps or the like. 
         [0107]    The mask  57  is disposed between the metal foil  20  (the first metal principal surface  21 ) and the injection nozzle  52  to allow the second aerosol AS 2  to be injected to the second film-forming surface  22 C of the second metal principal surface  22 . Then, as with the first film-forming step mentioned above, the film forming chamber  51  is sealingly closed and depressurized by a vacuum pump not shown to  10   2  Pa. 
         [0108]    Furthermore, the second mixed microparticles D 2  are supplied on the inside bottom plate  58 R of the aerosol generator  58  and then the opening of the container  58 P is closed with the stopper  58 Q. 
         [0109]    As with the first film-forming step, subsequently, the regulator  59  placed at some point in the gas pipe P 1  is controlled to flow a predetermined flow rate of carrier gas (not shown) from the gas bomb GB. This carrier gas will flow in the aerosol generator  58  through the gas pipe P 1 . Accordingly, this carrier gas causes the second mixed microparticles D 2  to be raised or stirred up in a space between the inside bottom plate  58 R and the stopper  58 Q, thereby producing the second aerosol AS 2 . Thus, the second mixed microparticles D 2  of a predetermined carrying quantity per unit time, which is determined by the flow rate of carrier gas, are carried by the carrier gas. 
         [0110]    The thus produced second aerosol AS 2  is delivered to the injection nozzle  52  of the film forming chamber  51  through the aerosol pipe P 2  as with the first film-forming step. 
         [0111]    The second aerosol AS 2  delivered to the injection nozzle  52  is further accelerated through the tapered injection part  52 H and injected to the second film-forming surface  22 C of the second metal principal surface  22  of the metal foil  20 . Thus, the second mixed microparticles D 2  collide with and are deposited on the second metal principal surface  22 . 
         [0112]    The slide part SW of the metal foil support member  53  holding the metal foil  20  is moved in the plane direction DS to form the second film  12  over the entire second film-forming surface  22 C of the second metal principal surface  22  of the metal foil  20 . 
         [0113]    The metal foil  20  held in the metal foil support member  53  and subjected to injection of the second aerosol AS 2  is shown in  FIGS. 8 and 9  when viewed from the thickness direction DT of the metal foil  20 . The details are further explained referring to the drawings. 
         [0114]    A region of the second metal principal surface  22  with which the second mixed microparticles D 2  is colliding to form the second film  12  is referred to as a second film forming region R. A region of the overlapping portion LW (the first film  11 ) that overlaps the second film-forming region R when viewed in the thickness direction DT of the metal foil  20  is referred to as a film-forming overlap region RW. In the manufacturing method of the film-formed body  1  in the first embodiment, accordingly, this film-forming overlap region RW is placed in the recess  56  of the metal foil support member  53  (see  FIG. 8 ). On the other hand, a region of the first exposed portion  21 F of the first metal principal surface  21  of the metal foil  20 , the region overlapping with the second film-forming region R, is referred to as a film-forming non-overlap region RX. In the first embodiment, this film-forming non-overlap region RX is placed on the support surface  55  of the metal foil support member  53  (see  FIG. 9 ). 
         [0115]    As above, while the film-forming overlap region RW is received in the recess  56 , the film-forming non-overlap region RX is placed on the support surface  55 . The film-forming ease is made uniform between a portion overlapping with the film-forming overlap region RW and a portion overlapping with the film-forming non-overlap region RX in the second film-forming surface  22 C, so that the second mixed microparticles D 2  uniformly collide with and are deposited on the second film-forming surface  22 C of the second metal principal surface  22 . 
         [0116]    On the second film-forming surface  22 C of the second metal principal surface  22 , the second film  12  made of the material (lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the second microparticles D 2  is formed uniformly. 
         [0117]    In the manufacturing method of the film-formed body  1  in the first embodiment, furthermore, the first film  11  having the thickness T 1  in the thickness direction DT of the metal foil  20  is positioned in the recess  56  depressed lower than the support surface  55  in the thickness direction DT, and then the second film  12  is formed on the second metal principal surface  22 . As compared with the case where the first film  11  is not placed in the recess  56 , the above case can reduce the influence of the thickness T 1  of the first film  11 . Specifically, if he first film  11  is not received in the recess  56 , for example, a step or shoulder corresponding to the thickness of the first film  11  occurs on the second metal principal surface of the metal foil. In the case where the second film is formed on this second metal principal surface by use of the second film-forming device  50 , accordingly, the thickness of the second film may differ between the portion overlapping with the film-forming overlap region RW and the portion overlapping with the film-forming non-overlap region RX or a step or shoulder may occur. 
         [0118]    On the other hand, the manufacturing method of the film-formed body  1  in the first embodiment can appropriately form the second film  12  by preventing the defects that the thickness of the second film  12  differs or a step occurs according to different portions of the second metal principal surface  22  (the second film-forming surface  22 C), that is, between the portion overlapping with the film-forming overlap region RW and the portion overlapping with the film-forming non-overlap region RX. 
         [0119]    The manufacturing method of the film-formed body  1  of the first embodiment adopts the aerosol deposition method in the second film-forming step. For example, this can decrease the collision speed of the second aerosol SA 2  than the case of using thermal spraying or cold spraying. It is therefore possible to form a film on the metal foil  20  while preventing deformation of the metal foil  20  such as depression, bending, and break. 
         [0120]    Following the second film-forming step, the third film  13  is further formed on the second film  12  by using the second film-forming device  50  again. 
         [0121]    To be specific, instead of the second mixed microparticles D 2 , third microparticles D 3  made of phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) powder are supplied on the inside bottom plate  58 R in the aerosol generator  58  shown in  FIG. 6 . Then, the opening of the container  58 P is closed with the closing stopper  58 Q. In a similar manner to the above film-forming of the second film  12 , the regulator  59  is controlled to flow a predetermined flow rate of carrier gas (not shown) from the gas bomb GB, the third microparticles D 3  thus form third aerosol AS 3  in the aerosol generator  58 . 
         [0122]    The thus produced third aerosol AS 3  is delivered to the injection nozzle  52 , further accelerated through the injection part  52 H, and injected to the second film  12 . At that time, the slide part SW of the metal foil support member  53  holding the metal foil  20  is moved in the plane direction DS to form the third film  13  on the metal foil  20 . 
         [0123]    Thus, on the second film  12 , the third film  13  made of the material (phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the third microparticles D 3  is formed. The aforementioned film-formed body  1  is completed (see  FIGS. 1 ,  2 , and  3 ). 
       FIRST MODIFIED EXAMPLE  
       [0124]    The film-formed body  1  of the first modified example of the invention will be explained referring to  FIGS. 1 to 3 ,  7 ,  10 , and  11 . 
         [0125]    The first modified example is identical to the above first embodiment excepting that a depth F 2  of a recess  156  in a metal foil support member  153  of a second film-forming device  150  used in the second film-forming step is larger than the thickness T 1  of the first film  11  formed on the metal foil  20 . 
         [0126]    Accordingly, the following explanation will be made with a focus on differences from the first embodiment and identical parts are not explained or are briefly mentioned. The identical parts provide the same operations and effects as those in the first embodiment. Further, the identical parts are given the same reference numbers as those in the first embodiment. 
         [0127]      FIG. 10  is a schematic view of the second film-forming device  150  used in the first modified example. This device  150  includes a film forming chamber  151  and, as with the first embodiment, an aerosol generator  58 , a regulator  59 , a gas bomb GB, a gas pipe P 1 , and an aerosol pipe P 2 . 
         [0128]    The film forming chamber  151  includes a metal foil support member  153  for supporting the metal foil  20  while exposing the second metal principal surface  22  and an injection nozzle  52  identical to that in the first embodiment. 
         [0129]    The metal foil support member  153  includes a holding part  154  for holding the metal foil  20  and a slide part SW for moving the metal foil  20  held in the holding part  154  in the plane direction as shown in  FIG. 7 . This metal foil support member  153  is further arranged to place a mask  157  between the injection nozzle  52  and the metal foil  20 . The mask  157  is formed with a through hole for forming the second film  12  in a predetermined position on the second metal principal surface  22 . 
         [0130]    The holding part  154  made of metal includes a recess  156  centrally formed therein and configured to be slightly larger than the plane shape (a rectangular shape in this modified example) of the first film  11  to receive the first film  11  and a support surface  155  located along the circumference of the recess  156  and raised by a step from the recess  156 . 
         [0131]    Depth F 2  of the recess  156  of the holding part  154  is larger than the thickness T 1  of the first film  11  formed on the metal foil  20 . As shown in  FIGS. 10 and 11 , specifically, the entire first film  11  is received in the recess  156  when the metal foil  20  formed with the first film  11  is held by the metal foil support member  153 . On the other hand, the support surface  155  of the metal foil support member  153  can hold the first exposed portion  21 F of the first metal principal surface  21 . This can prevent the occurrence of a step or shoulder in the second metal principal surface  22  (the second film-forming surface  22 C) and hence keep the second metal principal surface  22  flat. 
         [0132]    In the second film-forming step, furthermore, the film-forming non-overlap region RX of the first exposed portion  21 F is placed in contact with and supported by the support surface  155  of the metal foil support member  153 . This prevents the first exposed portion  21 F of the film-forming non-overlap region RX from separating from the support surface  155  around the first film  11 . This also can avoid the occurrence of differences in ease of forming the second film  12  in association with the separation. 
         [0133]    Subsequently, the following explanation will be given to the second film-forming step using the aforementioned second film-forming device  150  to form the second film  12  on the metal foil  20  formed with the first film  11 , referring to  FIG. 10 . 
         [0134]    Firstly, the metal foil  20  formed with the first film  11  produced in the first film-forming step in the first embodiment is prepared. This metal foil  20  is set in the metal foil support member  153  in the film forming chamber  151 . To be concrete, the entire first film  11  is received in the recess  156  of the metal foil support member  153  so that the first exposed portion  21 F of the first metal principal surface  21  is placed in contact with and held on the support surface  155 . In this way, the second metal principal surface  22  of the metal foil  20  is placed to face the injection nozzle  52 . At that time, the second metal principal surface  22  is made flat having no step or shoulder. 
         [0135]    Thereafter, as with the first embodiment, the second aerosol AS 2  delivered to the injection nozzle  52  is injected toward the second film-forming surface  22 C of the second metal principal surface  22  to make the second mixed microparticles D 2  collide and be deposited thereon. Thus, the second film  12  made of the material (lithium cobalt oxide and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the second mixed microparticles D 2  is formed. While this second film  12  is formed, the first metal principal surface  21  does not separate from the support surface  155 . Thus, the second film  12  can be formed without differences in the ease of film-forming caused by the separation. 
         [0136]    Following the second film-forming step, furthermore, the third film  13  is formed on the second film  12  by using the second film-forming device  150  again. To be concrete, instead of the second mixed microparticles D 2 , the third microparticles D 3  made of phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) powder are supplied on the inside bottom plate  58 R in the aerosol generator  58  shown in  FIG. 10 . 
         [0137]    Thus, the third film  13  made of the material (phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the third microparticles D 3  is formed. The film-formed body  1  is completed (see  FIGS. 1 ,  2 , and  3 ). 
       Second Embodiment  
       [0138]    A second embodiment of the invention will be explained below referring to FIGS.  2  and  12 - 18 . 
         [0139]    A film-formed body  101  in the second embodiment is first explained.  FIG. 12  is a perspective view of the film-formed body  101  and  FIG. 2  is a sectional view (section C-C in  FIG. 12 ) of the film-formed body  101 , respectively. 
         [0140]    The film-formed body  101  in the second embodiment includes a long-strip shaped metal foil  120  made of stainless steel, a first film  111  containing a mixture of lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ), and a second film  112  containing a mixture of lithium cobalt oxide (LiCoO 2 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). The film-formed body  101  further includes a third film  113  made of phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). Those first film  111 , second film  112 , and third film  113  also each have a rectangular strip shape extending in a longitudinal direction (from lower left to upper right in  FIG. 12 ) of the metal foil  120 . 
         [0141]    The film-formed body  101  is configured such that, on the metal foil  120 , the first film  111  is formed on a first metal principal surface  121  facing upward in  FIGS. 2 and 12 , the second film  112  is formed on a second metal principal surface  122  facing downward in  FIGS. 2 and 12 , and further the third film  113  is formed on the second film  112 . 
         [0142]    As shown in the sectional view ( FIG. 2 ) of the film-formed body  101 , the width (a lateral direction in  FIG. 2 ) of the second film  112  is larger than the width of the first film  111 . Accordingly, the entire first film  111  is also an overlapping portion LW overlapping with the second film  112  when viewed in a thickness direction DT of the metal foil  120 . 
         [0143]    It is to be noted that when the above strip-shaped film-formed body  101  is cut into pieces in the longitudinal direction and the pieces are laminated in the thickness direction DT, this laminated body can constitute a power generating element BP of a bipolar secondary battery as shown in  FIG. 4 , as with the first embodiment. 
         [0144]    The first film  111 , the second film  112 , and the third film  113  of the film-formed body  101  are formed by the aerosol deposition method using a third film-forming device  240  mentioned later. 
         [0145]    A method for manufacturing the film-formed body  101  in the second embodiment will be explained below referring to the drawings. 
         [0146]      FIG. 14  is a schematic view of the third film-forming device  240 . This third film-forming device  240  includes a film forming chamber  241 , a first aerosol generator  248 , a second aerosol generator  258 , a third aerosol generator  268 , a first regulator  249 , a second regulator  259 , a third regulator  269 , three gas bombs GB, GB, GB, gas pipes P 1 , and aerosol pipes P 2 . 
         [0147]    The three gas bombs GB, GB, GB are each filled with high-pressure argon gas used for carrier gas (not shown). Each gas bomb GB, GB, GB feeds carrier gas to the first aerosol generator  248 , the second aerosol generator  258 , or the third aerosol generator  268  through the corresponding metal gas pipe P 1  connected to the subject gas bomb GB. At some point in the gas pipe P 1 , the first regulator  249 , the second regulator  259 , or the third regulator  269  is placed to control the flow rate of the carrier gas to be fed from the corresponding gas bomb GB. 
         [0148]    Furthermore, the first, second, third aerosol generators  248 ,  258 , and  269  include bottom-closed cylindrical containers  248 P,  258 P, and  268 P, closing stoppers  248 Q,  258 Q, and  268 Q for closing openings of the containers  248 P,  258 P, and  268 P, and inside bottom plates  248 R,  258 R, and  268 R, respectively. Each of the inside bottom plates  248 R,  258 R, and  268 R has a meshed plate surface and is placed, like a raised bottom, at a predetermined distance from the bottom (a lower position in  FIG. 14 ) of the container  248 P,  258 P, or  268 P. 
         [0149]    In each closing stopper  248 Q,  258 Q, and  268 Q, the corresponding gas pipe P 1  and aerosol pipe P 2  are inserted to pass through. In each inside bottom plate  248 R,  258 R, and  268 R, the corresponding gas pipe P 1  is inserted to pass through as shown in  FIG. 14 . 
         [0150]    The inside bottom plate  248 R in the first aerosol generator  248  holds, on its side facing the stopper  248 Q, first mixed microparticles D 1  containing a mixture of lithium titanium oxide (Li 4 Ti 5 O 12 ) powder and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) powder. A mesh pore diameter of the plate surface of the inside bottom plate  248 R is smaller than a particle diameter of the first mixed microparticles D 1 . Consequently, this inside bottom plate  248 R does not allow the first mixed microparticles D 1  to pass through but does allow gas, i.e., the carrier gas (not shown) to pass through. The first aerosol generator  248  therefore can generate first aerosol AS 1  in which the first mixed microparticles D 1  are dispersed in the carrier gas. 
         [0151]    The inside bottom plate  258 R in the second aerosol generator  258  holds, on its surface facing the stopper  258 Q, second mixed microparticles D 2  containing a mixture of lithium cobalt oxide powder and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) powder. The second aerosol generator  258  thus can generate second aerosol AS 2  in which the second mixed microparticles D 2  are dispersed in the carrier gas (not shown), as with the first aerosol generator  248 . 
         [0152]    The inside bottom plate  268 R in the third aerosol generator  268  holds, on its surface facing the stopper  268 Q, third microparticles D 3  containing phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) powder. Accordingly, the third aerosol generator  268  can generate, as with the first and second aerosol generators  248  and  258 , third aerosol AS 3  in which the third microparticles D 3  are dispersed in the carrier gas. 
         [0153]    The film forming chamber  241  includes a reel-out part RS for reeling out the metal foil  120 , a first backup roll member  243  having a cylindrical surface, two second backup roll members  253 ,  253 , an auxiliary roll member  273 , and a reel-up part RE for reeling in the film-formed body  101 . In addition, the film forming chamber  241  includes a first injection nozzle  242  for injecting the first aerosol AS 1 , a second injection nozzle  252  for injecting the second aerosol AS 2 , and a third injection nozzle  262  for injecting the third aerosol AS 3 . This film forming chamber  241  is divided into a first film forming chamber  241 A, a second film forming chamber  241 B, and a third film forming chamber  241 C by partition walls  280  that do not allow the powder to pass through. Each of the film forming chambers  241 A,  241 B, and  241 C can be reduced in pressure to  10   −1  Pa by use of a vacuum pump not shown. 
         [0154]    The reel-out part RS reels out the metal foil  120  toward the first backup roll member  243  to move the metal foil  120  in the longitudinal direction DM. On the other hand, the reel-up part RE reels up a completed film-formed body  101  having been applied with the third aerosol AS 3  by moving the film-formed body  101  in the longitudinal direction DM. 
         [0155]    The first backup roll member  243  is placed in the first film forming chamber  241 A and has a cylindrical peripheral wall  243 S made of metal, a part of which contacts with the second metal principal surface  122  of the metal foil  120 . The first backup roll member  243  can hold the metal foil  120  so that the first metal principal surface  121  of the metal foil  120  faces the first injection nozzle  242 . 
         [0156]    The second backup roll members  253 ,  253  each made of metal placed in the second film forming chamber  241 B and the third film forming chamber  241 C respectively include a recess (a groove)  256  located in the center in the axial direction and recessed along a peripheral direction and support surfaces  255  provided on both sides (upper and lower sides in  FIG. 15 ) of the recess  256  in the axial direction and having a larger diameter than that of the recess  256  as shown in  FIG. 15 . The recess  256  has a slightly larger size (width) in the axial direction of the second backup roll member  253  than the width of the strip-shaped first film  111 . A bottom surface  256 D of this recess  256  is defined by an exposed part of the metal forming the second backup roll member  253 . 
         [0157]    Depth F 3  of the recess  256  (a distance in a radial direction from the support surface  255  to the bottom surface  256 D) is set to be equal to the thickness T 1  of the first film  111  formed on the metal foil  120 . Accordingly, when a part of the metal foil  120  formed with the first film  111  is to be supported by the second backup roll member  253 , the first film  111  can be received in the recess  256  and contact with the bottom surface  256 D (see  FIG. 16 ). 
         [0158]    On the other hand, when the part of the metal foil  120  formed with the first film  111  is to be supported by the second backup roll member  253 , the support surfaces  255  support part of first exposed portions  121 F of the first metal principal surface  121  of the metal foil  120 . 
         [0159]    Each support surface  255  of the second backup roll member  253  is coated with a film SF 2  (Thickness TS) made of lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) as with the first film  111 . Thus, each support surface  255  has first hardness. On the other hand, the bottom surface  256 D of the recess  256  is made of the metal forming the second backup roll member  253  and hence has second hardness different from the first hardness. As with the first embodiment, those first hardness and second hardness are determined to prevent a difference in the ease of forming the second film  112  on the second film-forming surface  122 C of the second metal principal surface  122  (e.g., the reactive force the second aerosol AS 2  (the second mixed microparticles D 2 ) receives from the metal foil  120  when collides therewith) and make the ease of film-forming uniform in the plane direction. When the second film  112  is to be formed, accordingly, the second film  112  can be formed with uniform thickness and quality over the second film-forming surface  122 C of the second metal principal surface  122 . 
         [0160]    As shown in  FIGS. 14 and 15 , the first injection nozzle  242  is oriented perpendicularly to a portion of the metal foil  120  held by the peripheral wall  243 S of the first backup roll member  243  in the first film forming chamber  241 A. The second injection nozzle  252  is oriented perpendicularly to a portion of the metal foil  120  held in the recess  256  and the support surfaces  255  of the second backup roll member  253  in the second film forming chamber  241 B. The third injection nozzle  262  is oriented perpendicularly to a portion of the metal foil  120  held in the recess  256  and the support surfaces  255  of the second backup roll member  253  in the third film forming chamber  241 C. 
         [0161]    The first injection nozzle  242 , the second injection nozzle  252 , and the third injection nozzle  262  are repeatedly moved in a short side direction of the metal foil  120  (in a direction from a back side to a front side in  FIG. 14 ) to form the first film  111 , the second film  112 , or the third film  113  on the metal foil  120 . Between the first injection nozzle  242  and the metal foil  120 , a first mask  247  formed with a through hole is placed to form the first film  111  in a predetermined position on the first metal principal surface  121 . Between the second injection nozzle  252  and the metal foil  120 , a second mask  257  formed with a through hole is placed to form the second film  112  in a predetermined position on the second metal principal surface  122 . Between the third injection nozzle  262  and the metal foil  120 , furthermore, a third mask  267  formed with a through hole is placed to form the third film  113  on the second film  112 . 
         [0162]    A method for manufacturing the film-formed body  101  by using the aforementioned third film-forming device  240  is explained below, referring to  FIG. 14 . 
         [0163]    The first film  111  is first formed with the thickness T 1  on the first metal principal surface  121  of the metal foil  120  by use of the first backup roll member  243  and the first injection nozzle  242  in the film forming chamber  241 . 
         [0164]    To be specific, the first film forming chamber  241 A, the second film forming chamber  241 B, and the third film forming chamber  241 C of the film forming chamber  241  are all reduced in pressure to  10   2  Pa. The first mixed microparticles D 1  are supplied in the first aerosol generator  248 , which is then closed. The first regulator  249  located at some point in the gas pipe P 1  is controlled to flow a predetermined flow rate of carrier gas (not shown) from the gas bomb GB. This carrier gas flows in the first aerosol generator  248  through the gas pipe P 1 . This carrier gas raises or stirs up the first mixed microparticles D 1  in a space between the inside bottom plate  248 R and the closing stopper  248 Q, forming the first aerosol AS 1 . Thus, the first mixed microparticles D 1  of a predetermined carrying quantity per unit time are carried by the carrier gas. 
         [0165]    The thus produced first aerosol AS 1  is delivered to the first injection nozzle  242  in the film forming chamber  241  (the first film forming chamber  241 A) through the aerosol pipe P 2  and injected toward the first film-forming surface  121 C of the first metal principal surface  121  of the metal foil  120 . Accordingly, the first mixed microparticles D 1  collide with and are deposited on the first metal principal surface  121 . 
         [0166]    As above, on the first film-forming surface  121 C of the first metal principal surface  121 , the first film  111  made of the material (lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the first mixed microparticles D 1  is formed with the thickness T 1   
         [0167]    Next, a second film-forming step is explained to form the second film  112  on the second metal principal surface  122  of the metal foil  120  by using the second backup roll member  253  and the second injection nozzle  252  in the second film forming chamber  241 B. 
         [0168]    Firstly, the metal foil  120  formed with the first film  111  is supported by the second backup roll member  253  in the second film forming chamber  241 B. To be concrete, as shown in  FIG. 16  showing an enlarged view of a part D in  FIG. 14 , the entire first film  111  is received in the recess  256  of the second backup roll member  253  so that a part of the first exposed portion  121 F not formed with the first film  111 , of the first metal principal surface  121  of the metal foil  120 , is placed, or wound, in contact with the support surfaces  255 . Thus, a part of the second metal principal surface  122  of the metal foil  120  faces the second injection nozzle  252 . In this state, a part of the second metal principal surface  122  has no step or the like. 
         [0169]    The second mixed microparticles D 2  are supplied in the second aerosol generator  258 , which is then closed. The second regulator  259  placed at some point in the gas pipe P 1  is controlled to flow a predetermined flow rate of carrier gas (not shown) from the gas bomb GB. This carrier gas flows in the second aerosol generator  258  through the gas pipe P 1 , thereby transforming the second mixed microparticles D 2  into the second aerosol AS 2 . Thus, the second mixed microparticles D 2  of a predetermined carrying quantity per unit time are carried by the carrier gas. 
         [0170]    The thus produced second aerosol AS 2  is delivered to the second injection nozzle  252  in the film forming chamber  241  (the second film forming chamber  241 B) through the aerosol pipe P 2  and injected toward the second film-forming surface  122 C of the second metal principal surface  122  of the metal foil  120 . Accordingly, the second mixed microparticles D 2  collide with and are deposited on the second metal principal surface  122 . 
         [0171]    The metal foil  120  held by the second backup roll member  253  and applied with the second aerosol AS 2  will be further explained in detail referring to  FIGS. 17 and 18  showing the metal foil  120  viewed in the thickness direction DT. 
         [0172]    A region of the second metal principal surface  122  with which the second mixed microparticles D 2  are colliding to form the second film  112  is referred to as a second film forming region R. A region of the overlapping portion LW (the first film  111 ), the region overlapping the second film-forming region R when viewed in the thickness direction DT, is referred to as a film-forming overlap region RW. In the manufacturing method of the film-formed body  101  in the second embodiment, this film-forming overlap region RW is placed in the recess  256  of the second backup roll member  253  (see  FIG. 17 ). On the other hand, a region of the first exposed portion  121 F of the first metal principal surface  121  of the metal foil  120 , the region overlapping the second film-forming region R when viewed in the thickness direction DT of the metal foil  120 , is referred to a film-forming non-overlap region RX. In the second embodiment, therefore, this film-forming non-overlap region RX is positioned on the support surface  255  of the second backup roll member  253  (see  FIG. 18 ). 
         [0173]    As above, when the film-forming overlap region RW is received in the recess  256  while the film-forming non-overlap regions RX are placed on the support surfaces  255 , the each of film-forming is made uniform between the portion overlapping with the film-forming overlap region RW and the portion overlapping with the film-forming non-overlap region RX in the second film-forming surface  122 C of the second metal principal surface  122 . Therefore, the second mixed microparticles D 2  uniformly collide with and are deposited on the second film-forming surface  122 C of the second metal principal surface  122 . 
         [0174]    On the second film-forming surface  122 C of the second metal principal surface  122 , the second film  112  made of the material (lithium cobalt oxide and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the second mixed microparticles D 2  is formed uniformly. 
         [0175]    Following the above second film-forming step, the third film  113  is formed on the second film  112  formed on the second metal principal surface  122  of the metal foil  120  by the second backup roll member  253  in the third film forming chamber  241 C. 
         [0176]    To be concrete, firstly, the third microparticles D 3  are supplied in the third aerosol generator  268 , which is then closed. The third regulator  269  placed at some point in the gas pipe P 1  is controlled to flow a predetermined flow rate of carrier gas (not shown) from the gas bomb GB. This carrier gas flows in the third aerosol generator  268  through the gas pipe P 1 , thereby transforming the third microparticles D 3  into the third aerosol AS 3 . Accordingly, the third microparticles D 3  of a predetermined carrying quantity per unit time are carried by the carrier gas. 
         [0177]    The thus produced third aerosol AS 3  is delivered to the third injection nozzle  262  in the film forming chamber  241  (the third film forming chamber  241 C) through the aerosol pipe P 2  and injected toward the second film  112  formed on the second metal principal surface  122  of the metal foil  120  to make the third microparticles D 3  collide and be deposited on the second film  112 . 
         [0178]    Thus, the third film  113  made of the material (phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 )) originating from the third microparticles D 3  is formed. The aforementioned film-formed body  101  is consequently completed (see  FIGS. 2 ,  12 , and  13 ). 
         [0179]    According to the method for manufacturing the film-formed body  101  in the second embodiment mentioned above, in addition to the operations and effects described in the first embodiment, the first film  111 , the second film  112 , and the third film  113  can be continuously formed on the strip-shaped metal foil  120  by use of the third film-forming device  240 . This can reduce the number of working steps. 
         [0180]    The present invention is explained in the above first and second embodiments and the first modified example but not limited thereto. The present invention may be embodied in other specific forms without departing from the essential characteristics thereof. 
         [0181]    For instance, in the first embodiment and others, the film-formed body constitutes a part of the power generating element BP usable for a bipolar secondary battery. As an alternative, the film-formed body has only to include a second film formed on a second film-forming surface of a substrate by the aerosol deposition method and a first film including an overlapping portion that overlaps with the second film when viewed in the thickness direction of the substrate. Examples thereof are components for fuel battery, piezoelectric substances, condenser parts directly formed on the substrate, and others. 
         [0182]    The above first film is made of the material containing a mixture of lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) and the second film is made of the material containing a mixture of lithium cobalt oxide (LiCoO 2 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). As an alternative, the second film may be made of a material containing a mixture of lithium titanium oxide (Li 4 Ti 5 O 12 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ) and the first film may be made of a material containing lithium cobalt oxide (LiCoO 2 ) and phosphate solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 ). 
         [0183]    In the first embodiment and others, the first film is made by the aerosol deposition method. However, the manufacturing method thereof is not particularly limited. The first film may be made by for example plating, coating, sputtering, or another technique. Furthermore, the second film is made by the aerosol deposition method. As an alternative, the second film may be made by a gas deposition method in which a raw material is evaporated and vaporized and then precipitated in the form of nanoparticles in gas phase, and the precipitated nanoparticles are dispersed in carrier gas and caused to collide with a substrate to form the second film. 
         [0184]    The above support member is an integral member formed with the recess. Alternatively, the support member may be constituted of a plurality of parts or components. For example, a member formed with a through hole in only a portion corresponding to a recess may be placed on a base member to provide a support surface and a recess. 
         [0185]    In the first and second embodiments, the metal forming the support member is exposed on the bottom surface of the recess, the support surface is coated with the same film as the first film, providing a difference between the hardness of the support surface and the bottom surface of the recess. Alternatively, the hardness of the support surface and the hardness of the bottom surface of the recess have only to be different from each other to reduce a difference in thickness between a portion of the second film overlapping with the film-forming overlap region and a portion of the second film overlapping with the film-forming non-overlap region. The above carrier gas is argon gas but may be selected appropriately according to characteristics of a film to be formed on a film-forming surface, compositions of microparticles, and others. For example, it may be dry air, nitrogen gas, helium gas, oxygen gas. The above carrier gas is a single kind of gas but may be a mixture of plural different kinds of gases.