Patent Publication Number: US-2021180205-A1

Title: Substrate holder

Description:
TECHNICAL FIELD 
     The present disclosure relates to a substrate holder configured to hold a substrate. 
     BACKGROUND ART 
     A general procedure forms wirings, bumps (salient electrodes) and the like on the surface of a substrate such as a semiconductor wafer or a printed circuit board. An electroplating technique is known as a method of forming such wirings, bumps and the like. A plating apparatus employed for the electroplating technique is provided with a substrate holder that is configured to seal an end face of a circular or polygonal substrate and hold the substrate with a surface to be plated (a plating surface) of the substrate exposed. A procedure of plating the surface of a substrate by such a plating apparatus soaks the substrate holder with the substrate held thereby into a plating solution. 
     A substrate holder suitable for a large-sized, especially rectangular substrate has been known as described in Japanese Unexamined Patent Publication No. 2018-40045 (Patent Document 1) and Japanese Unexamined Patent Publication No. 2019-7075 (Patent Document 2). Japanese Unexamined Patent Publication No. 2018-40045 (Patent Document 1) describes a substrate holder configured to hold a substrate by fixing the substrate to a back plate by means of a clip, subsequently laying the back plate over a front plate, and fixing the front plate to the back plate by means of a clamp. Japanese Unexamined Patent Publication No. 2019-7075 (Patent Document 2) describes a substrate holder configured to feed the electric power via a bus bar to a plurality of substrate contacts placed in the periphery of a substrate. 
     Japanese Unexamined Patent Publication No. 2008-133526 (Patent Document 3) discloses an example of a plating jig serving to improve application of a pressing force to a substrate. This example is configured to lay a pressing member over a substrate placed in a recess on a jig body and to fix a cover member provided with a spring corresponding to the center of the substrate to an upper face of the jig body. This compresses the spring between the cover member and the pressing member to press the substrate against the seal member and thereby seal the substrate. 
     Japanese Unexamined Patent Publication No. 2007-46154 (Patent Document 4) discloses a work piece holder configured such that a locking mechanism of a ring is locked to a flexible member locked to a work piece holder body side and that the ring is pulled toward the work piece holder body side by the flexible member to press the substrate by a seal face of the ring. This work piece holder includes an expandable and contractable bag placed inside of the work piece holder body to deform the flexible member to such a degree as to be engageable with the locking mechanism of the ring. 
     RELATED ART DOCUMENT 
     Patent Document 
     Patent Document 1: Japanese Unexamined Patent Publication No. 2018-40045 
     Patent Document 2: Japanese Unexamined Patent Publication No. 2019-7075 
     Patent Document 3: Japanese Unexamined Patent Publication No. 2008-133526 
     Patent Document 4: Japanese Unexamined Patent Publication No. 2007-46154 
     SUMMARY OF INVENTION 
     These substrate holders use a seal that is formed in a continuous and integral shape along an outer circumference of the substrate and that is brought into contact with the substrate to protect a substrate contact from a plating solution. In order to achieve appropriate sealing of the substrate contact, a seal needs to be brought into contact with the substrate with a uniform pressing force over the full length of the seal. The substrate is, however, more likely to warp with an increase in size and/or thinning of the substrate. This makes it difficult for a continuous and integral seal to be brought into contact with the substrate with a uniform pressing force over the full length of the seal. Moreover, the continuous and integral seal suitable for the large-sized substrate needs to ensure the surface accuracy and/or the dimensional accuracy of the seal itself and relevant components over a long distance and a wide range corresponding to an outer circumferential part of the substrate. It is, however, difficult to manufacture the seal and the relevant components having the sufficient surface accuracy and/or the sufficient dimensional accuracy. This is likely to increase the cost of the substrate holder. Furthermore, the weight of the substrate holder is likely to increase with an increase in size of the substrate. 
     In some cases, the substrate holder may be required to position the seal and/or the substrate contact in a limited area corresponding to a contact allowable area of the substrate where the seal and/or the substrate contact is allowed to be brought into contact with. 
     There is also a need to reduce a load applied to the substrate when the seal is pressed against the substrate. 
     An object of the present disclosure is to solve at least part of the problems described above. 
     According to one aspect of the present disclosure, there is provided a substrate holder configured to hold a substrate, the substrate holder comprising: a first holding member; and a second holding member configured to hold the substrate between the first holding member and the second holding member, wherein the first holding member comprises: at least one substrate contact arranged to come into contact with the substrate; at least one seal member provided with a first seal portion configured to cover periphery of a leading end portion of one or a plurality of the substrate contacts; and at least one bus bar electrically connected with the one or plurality of substrate contacts and provided with one or a plurality of first through holes to receive the first seal portion, wherein the leading end portion of the one or plurality of substrate contacts is arranged to pass through the first through hole from a side opposite to the second holding member toward the second holding member and is fixed to the bus bar in a state that the periphery of the leading end portion of the one or plurality of substrate contacts is covered by the first seal portion. 
     According to one aspect of the present disclosure, there is a substrate holder, comprising: a contact assembly provided with a contact configured as an electric contact to come into contact with an outer circumferential part of a first face of a substrate, a seal member provided with a seal portion configured to cover a periphery of a leading end portion of the contact and to come into contact with the first face, and a holder body configured to hold the contact and the seal member; a first plate located on a second face side of the substrate and configured to hold the substrate between the contact assembly and the first plate; at least one first pin fixed to the holder body of the contact assembly, extended toward the second face side on outside of the substrate, and provided with a locked portion; a locking member placed on the second face side relative to the first plate and configured to be displaceable between a locked state/position and an unlocked state/position with respect to the locked portion of the first pin; and at least one first biasing member placed between the locking member and the first plate along the outer circumferential part of the substrate such as to separate the locking member and the first plate from each other and compressed between the locking member and the first plate in the locked state/position to bias the first plate toward the contact assembly. 
     According to one aspect of the present disclosure, there is provided a substrate holder, comprising: a contact assembly provided with a contact configured as an electric contact to come into contact with an outer circumferential part of a first face of a substrate, a seal member provided with a seal portion configured to come into contact with the first face on inside of the contact, and a holder body configured to hold the contact and the seal member; a first plate located on a second face side of the substrate and configured to hold the substrate between the contact assembly and the first plate; a plurality of first pins, each being fixed to the holder body of the contact assembly, extended toward the second face side on outside of the substrate, and provided with a locked portion; a locking member placed on the second face side relative to the first plate and configured to be displaceable between a locked state/position and an unlocked state/position with respect to the locked portion of the first pin; and a plurality of first biasing members provided along the outer circumferential part of the substrate, placed between the locking member and the first plate such as to separate the locking member and the first plate from each other, and compressed between the locking member and the first plate in the locked state/position to bias the first plate toward the contact assembly. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a general layout drawing illustrating a plating apparatus with a substrate holder according to one embodiment of the present disclosure used therefor; 
         FIG. 2  is a perspective view illustrating the substrate holder viewed from a front face side thereof; 
         FIG. 3  is a perspective view illustrating the substrate holder viewed from a back face side thereof; 
         FIG. 4  is a perspective view illustrating the substrate holder in such a state that respective holding members are separated; 
         FIG. 5  is an enlarged perspective view illustrating an external connecting portion of the substrate holder; 
         FIG. 6  is a longitudinal sectional view illustrating a longitudinal member; 
         FIG. 7  is an exploded perspective view illustrating the longitudinal member; 
         FIG. 8  is a perspective view illustrating a bus bar viewed from a back face side thereof in one unit length of a contact seal module; 
         FIG. 9  is a perspective view illustrating a seal member viewed from a back face side thereof; 
         FIG. 10  is a perspective view illustrating a front plate viewed from a back face side thereof in one unit length of the contact seal module; 
         FIG. 11  is a cross sectional view illustrating the longitudinal member in closeup of the vicinity of a power feed module; 
         FIG. 12  is a perspective view illustrating close-up of the vicinity of a locking mechanism of the second holding member; 
         FIG. 13  is a back view illustrating close-up of the vicinity of the locking mechanism of the second holding member; 
         FIG. 14  is a sectional view taken along a line XIV-XIV in  FIG. 13  in a locked state; 
         FIG. 15  is a sectional perspective view taken along a line XV-XV in  FIG. 13  in the locked state; 
         FIG. 16  is a sectional perspective view taken along a line XVI-XVI in  FIG. 13  in the locked state; 
         FIG. 17  is a sectional perspective view taken along a line XVII-XVII in  FIG. 13  in the locked state; 
         FIG. 18  is a sectional perspective view corresponding to  FIG. 15  in a semi-locked state; 
         FIG. 19  is a sectional perspective view corresponding to  FIG. 16  in the semi-locked state; 
         FIG. 20  is a sectional perspective view corresponding to  FIG. 17  in the semi-locked state; 
         FIG. 21  is a sectional view taken along a line XXI-XXI in  FIG. 13 ; 
         FIG. 22  is a sectional view illustrating a substrate holder according to a modification; 
         FIG. 23  is an explanatory diagram illustrating a method of mounting a substrate to the substrate holder; 
         FIG. 24  is an explanatory diagram illustrating the method of mounting the substrate to the substrate holder; 
         FIG. 25  is an explanatory diagram illustrating the method of mounting the substrate to the substrate holder; 
         FIG. 26  is an explanatory diagram illustrating the method of mounting the substrate to the substrate holder; 
         FIG. 27  is a sectional view a illustrating contact position of a seal portion on a substrate; and 
         FIG. 28  is a schematic diagram illustrating an example of a substrate holder with the locking mechanism of the above embodiment applied to a continuous integral seal. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following describes embodiments of a plating apparatus and a substrate holder used in the plating apparatus according to the present disclosure with reference to attached drawings. In the attached drawings, identical or similar components are expressed by identical or similar reference signs. In the explanation of the respective embodiments, overlapping description with regard to the identical or similar components may be omitted. Characteristics and features described in each of the embodiments are applicable to the other embodiments so far as they are not incompatible with each other. 
     In the description hereof, the term “substrate” includes not only semiconductor substrates, glass substrates, liquid crystal substrates and printed circuit boards but magnetic recording media, magnetic recording sensors, mirrors, optical elements, micromachine elements or partially manufactured integrated circuits, and any other objects to be processed. The substrate may be in any of various shapes including polygonal shapes and circular shapes. Although the expressions such as “front face”, “back face”, “front”, “back”, “upper (above)”, “lower (below)”, “left” and “right” are used in the description hereof, these expressions only indicate the positions and the directions on the sheet surfaces of the illustrative drawings for the purpose of explanation and may be different from the positions and the directions in the actual layout, for example, during use of the apparatus. 
       FIG. 1  is a general layout drawing illustrating a plating apparatus with a substrate holder used therein according to one embodiment of the present disclosure. A plating apparatus  100  is configured to plate a substrate in such a state that the substrate is held by a substrate holder  200  (shown in  FIG. 2 ). The plating apparatus  100  is roughly divided into a load/unload module  110  configured to load the substrate to the substrate holder  200  or unload the substrate from the substrate holder  200 , a processing module  120  configured to process the substrate, and a cleaning module  50   a.  The processing module  120  further includes a pre-process/post-process module  120 A configured to perform pre-process and post-process of the substrate and a plating module  1208  configured to perform a plating process of the substrate. 
     The load/unload module  110  includes two cassette tables  25  and a substrate mounting/demounting mechanism  29 . The cassette table  25  is configured to mount thereon a cassette  25   a  with the substrate received therein. The substrate mounting/demounting mechanism  29  is configured to attach and detach the substrate to and from the substrate holder  200 . A stocker  30  is provided in a neighborhood of (for example, below) the substrate mounting/demounting mechanism  29  to place the substrate holders  200  therein. The cleaning module  50   a  includes a cleaning device  50  configured to clean and dry the substrate after the plating process. 
     A substrate transporter  27  is placed at a location surrounded by the cassette tables  25 , the substrate mounting/demounting mechanism  29  and the cleaning module  50   a,  and is configured by a carrier robot to transfer or convey the substrate between these components. The substrate transporter  27  is configured to be movable by a moving device  28 . For example, the substrate transporter  27  is configured to take out a substrate prior to plating from the cassette  25   a  and transfer the substrate to the substrate mounting/demounting mechanism  29 , to receive a substrate after plating from the substrate mounting/demounting mechanism  29 , to transfer the substrate after plating to the cleaning module  50   a,  and to take out a cleaned and dried substrate from the cleaning module  50   a  and place the cleaned and dried substrate into the cassette  25   a.    
     The pre-process/post-process module  120 A includes a pre-wet module  32 , a pre-soak module  33 , a pre-rinse module  34 , a blow module  35  and a rinse module  36 . The pre-wet module  32  serves to soak a substrate in pure water. The pre-soak module  33  serves to remove an oxide film on the surface of a conductive layer such as a seed layer formed on the surface of the substrate by etching. The pre-rinse module  34  serves to clean the pre-soaked substrate along with a substrate holder with a cleaning liquid (for example, pure water). The blow module  35  serves to drain the liquid from the cleaned substrate. The rinse module  36  serves to clean the plated substrate along with the substrate holder with the cleaning liquid. The pre-wet module  32 , the pre-soak module  33 , the pre-rinse module  34 , the blow module  35 , and the rinse module  36  are arranged in this sequence. This configuration is, however, only illustrative, and the pre-process/post-process module  120 A is not limited to this configuration described above but may adopt another configuration. 
     The plating module  120 B includes a plurality of plating device (plating tanks or cells)  39 , and an overflow tank  38 . Each of the plating device  39  is configured to place one substrate inside thereof and to soak the substrate in a plating solution kept inside thereof and plate the surface of the substrate by copper plating or the like. The type of the plating solution is not specifically limited, but any of various plating solutions may be used according to the purposes. 
     The plating apparatus  100  includes a holder transporter  37  that is located on a side of these components and configured to transfer the substrate holder  200  along with the substrate between these components and that adopts, for example, a linear motor system. This holder transporter  37  is configured to transfer the substrate holder between the substrate mounting/demounting mechanism  29 , the stocker  30 , the pre-wet module  32 , the pre-soak module  33 , the pre-rinse module  34 , the blow module  35 , the rinse module  36  and the plating device  39 . 
     The plating apparatus  100  having the configuration described above includes a controller  175  that serves a control module configured to control the respective components described above. The controller  175  includes a memory  175 B configured to store predetermined programs and a CPU  175 A configured to execute the programs stored in the memory  175 B. A storage medium that constitutes the memory  175 B is configured to store, for example, a variety of set data and various programs including a program to control the plating apparatus  100 . The programs include, for example, programs that perform transfer control of the substrate transporter  27 , mounting and demounting control of mounting and demounting the substrate to and from the substrate holder by the substrate mounting/demounting mechanism  29 , transfer control of the holder transporter  37 , control of the processings in the respective processing modules, control of the plating process in the respective plating device  39 , and control of the cleaning module  50   a.  The storage medium may include nonvolatile and/or volatile storage media. The storage medium used may be any of known storage media, for example, a computer readable memory such as a ROM, a RAM or a flash memory or a disk-type storage medium such as a hard disk, a CD-ROM, a DVD-ROM or a flexible disk. 
     The controller  175  is configured to make communication with a non-illustrated upper level controller that performs integrated control of the plating apparatus  100  and the other relevant devices and to send and receive data to and from a database of the upper level controller. Part or the entirety of the functions of the controller  175  may be configured by a hardware such as ASIC. Part or the entirety of the functions of the controller  175  may be configured by a sequencer. Part or the entirety of the controller  175  may be placed on inside and/or outside of a housing of the plating apparatus  100 . Part or the entirety of the controller  175  is connected to make communication with the respective components of the plating apparatus  100  by wire or wirelessly. 
     (Substrate Holder) 
       FIG. 2  is a perspective view illustrating the substrate holder viewed from a front face side.  FIG. 3  is a perspective view illustrating the substrate holder viewed from a back face side.  FIG. 4  is a perspective view illustrating the substrate holder in such a state that respective holding members are separated.  FIG. 5  is an enlarged perspective view illustrating an external connecting portion of the substrate holder. This substrate holder  200  includes a first holding member  210  and a second holding member  220  and holds a substrate W in such a state that the substrate W is placed between the first holding member  210  and the second holding member  220 . 
     The first holding member  210  includes a longitudinal member  211   a,  a longitudinal member  211   b,  a transverse member  212 , a transverse member  213 , a rail  215 , an arm  216 , and an external connecting portion  217 . The first holding member  210  also includes a plurality of pins  270  (shown in  FIG. 4 ) serving as a locking mechanism to lock the first holding member  210  to the second holding member  220 . The longitudinal member  211   a  and the longitudinal member  211   b  are extended approximately parallel to each other and respectively have a power feed device including a substrate contact (described later) serving as an electric contact that comes into contact with a front face of the substrate W to make the flow of electric current. This embodiment illustrates a configuration that only the longitudinal member  211   a  and the longitudinal member  211   b  are provided with the power feed devices. According to another embodiment, the transverse member  212  and/or the transverse member  213  may be provided with power feed devices, in place of or in addition to the longitudinal member  211   a  and/or the longitudinal member  211   b.  The transverse member  212  is configured to link the longitudinal member  211   a  and the longitudinal member  211   b  with each other on a side farther from the arm  216 . The transverse member  213  is configured to link the longitudinal member  211   a  and the longitudinal member  211   b  with each other on a side nearer to the arm  216 . The transverse members  212  and  213  serve to support the longitudinal members  211   a  and  211   b  and suppress deflection. The front face of the substrate W is exposed in an area surrounded by these longitudinal members  211   a  and  211   b  and transverse members  212  and  213 . According to a modification, the substrate holder may be formed in a portal shape with omission of the transverse members  212  and  213 . 
     The rail  215  is mounted approximately parallel to the arm  216 . The longitudinal members  211   a  and  211   b  are mounted to be slidable along the rail  215 . The rail  215  is configured such that the positions of the longitudinal members  211   a  and  211   b  are adjustable according to the dimensions of the substrate W by moving the longitudinal members  211   a  and  211   b  along the rail  215  to become closer to each other or to become away from each other. 
     The arm  216  is a grip portion held by the holder transporter  37  and serves as a part that is supported when the substrate holder is placed in each of the processing modules or tanks. The arm  216  is extended approximately perpendicular to the longitudinal member  211   a,  and the external connecting portion  217  is provided on one end of the arm  216 . According to another embodiment, the external connecting portions  217  may be provided on respective ends of the arm  216 . The external connecting portion  217  is an external connection terminal used to electrically connect the substrate holder  200  with an external power source and includes a plurality of externally connecting contacts configured by, for example, leaf electrodes (as shown in  FIG. 5 ). Part of the externally connecting contacts (on a front side of  FIG. 5 ) is electrically connected with a bus bar  218   a,  whereas another part of the externally connecting contacts (on a back side of  FIG. 5 ) is electrically connected with a bus bar  218   b.  The bus bars  218   a  and  218   b  may be appropriately covered with a cover or a protective member. The bus bar  218   a  is extended along a longitudinal direction of the arm  216  and is configured to be mechanically and electrically connected with a bus bar  260  of the longitudinal member  211   a  (shown in  FIG. 3 ). The bus bar  218   a  is configured to be connectable with the bus bar  260  of the longitudinal member  211   a  at a plurality of positions according to adjustment of the position of the longitudinal member  211   a.  The bus bar  218   b  is extended along the longitudinal direction of the arm  216  and is configured to be mechanically and electrically connected with a bus bar  260  of the longitudinal member  211   b  (shown in  FIG. 3 ). The bus bar  218   b  is configured to be connectable with the bus bar  260  of the longitudinal member  211   b  at a plurality of positions according to adjustment of the position of the longitudinal member  211   b.  In one example, the connecting positions of the bus bars  218   a  and  218   b  with the bus bars  260  of the longitudinal members  211   a  and  211   b  are placed inside of the cover or the protective member. 
     The second holding member  220  has a back plate  280  and a locking mechanism including lock plates  300  that are provided on the back plate  280  and that serve to lock the second holding member  220  on the first holding member  210 . The locking mechanism includes the lock plates  300  extended corresponding to the longitudinal members  211   a  and  211   b,  float plates  290  placed between the back plate  280  and the lock plates  300  and extended corresponding to the lock plates  300 , and biasing mechanisms  305  configured to generate a biasing force between the lock plates  300  and the float plates  290 . The details of the locking mechanism will be described later. 
     (Power Feed Module) 
       FIG. 6  is a longitudinal sectional view illustrating the longitudinal member. The longitudinal member  211   a  and the longitudinal member  211   b  have similar configurations. The following accordingly describes the longitudinal member  211   a  as an example. As illustrated, the longitudinal member  211   a  includes a front plate  250 , the bus bar  260 , a plurality of power feed modules  230  that are electrically connected with the bus bar  260 , and a plurality of pins  270  that are placed on respective sides of each of the power feed modules  230  (between adjacent power feed modules  230  and outside of power feed modules  230  on respective ends). In  FIG. 6 , an interval between adjacent pins  270  is expressed by d. The surface of the bus bar  260  other than some part is coated by insulation coating. More specifically, the surface of the bus bar  260  other than a contact location which a substrate contact  233  described later comes into contact with (surface of a projection  264 ) is coated by insulation coating. The insulation coating protects the bus bar  260  from the plating solution and prevents the electric current from directly flowing from the plating solution to the bus bar  260 . 
     As shown in  FIG. 3  and  FIG. 4 , the bus bar  260  is extended over the full length of the longitudinal member  211   a  and is configured to be mechanically connected with the rail  215  and to be mechanically and electrically connected with the bus bars  218   a  and  218   b  in the arm  216  (shown in  FIG. 5 ) as described above. The bus bar  260  is electrically connected with the external connecting portion  217  via the bus bars  218   a  and  218   b  in the arm  216 . As shown in  FIG. 2  and  FIG. 6 , the front plate  250  is provided on a front face side of the bus bar  260  and is extended along the bus bar  260  over the full length of the longitudinal member  211   a.  The front plate  250  serves along with a seal member  231  to shield the substrate contact  233  from the plating solution. The front plate  250  may be made of a material that is the same as the material of the seal member  231 . 
     The power feed modules  230  are power feed units that configure the power feed device and are respectively placed on the front face side of the bus bar  260  along the longitudinal member  211   a  as shown in  FIG. 6 . In this embodiment, the power feed modules  230  are placed between the bus bar  260  and the front plate  250 . As described later with reference to  FIG. 7 , each of the power feed modules  230  has a substrate contact  233  and is arranged such that a contact leading end  243  of the substrate contact  233  is extended across a through hole  263  of the bus bar  260  to a back face side of the bus bar  260  (a side opposite to the front plate  250 ) to come into contact with the substrate W. 
       FIG. 7  is an exploded perspective view illustrating the longitudinal member.  FIG. 8  is a perspective view illustrating the bus bar viewed from a back face side thereof.  FIG. 9  is a perspective view illustrating the seal member viewed from a back face side thereof.  FIG. 10  is a perspective view illustrating the front plate viewed from a back face side thereof.  FIG. 11  is a cross sectional view illustrating the longitudinal member in closeup of the vicinity of the power feed module. As shown in  FIG. 6 , the front plate  250  and the bus bar  260  are extended over the full length of the longitudinal member  211   a.    FIG. 7 , however, illustrates only portions corresponding to one power feed module  230 , with a view to avoiding the complication of illustration. 
     The power feed module  230  includes the seal member  231 , a support plate  232 , the substrate contact  233 , and a pressing plate  234 . The seal member  231  is an elastic member (made of an elastomer such as rubber) having a substantially rectangular shape and includes a seal portion  235 , a through hole  236  provided in the seal portion  235 , a seal portion  237  provided on a front face side of the seal member  231  (on an upper face in  FIG. 7 ), a through hole  238  provided outside of the through hole  236 , a seal potion  239  provided around the through hole  238  on a back face side of the seal member  231  (shown in  FIG. 9 ), a protrusion  240  provided outside of the through hole  238  on the back face side of the seal member  231  (shown in  FIG. 9 ), and cuts  241  configured to receive the pins  270 . 
     As shown in  FIG. 11 , the seal portion  235  is made to pass through the through hole  263  of the bus bar  260  and is exposed on a back face side of the longitudinal member  211   a  (on a lower side of this drawing). The seal portion  235  is formed in such a length as to be extended by a predetermined length from a back face of the bus bar  260 . The through hole  236  is provided in the seal portion  235  to penetrate from the front face side to the back face side of the seal member  231 . The contact leading end  243  of the substrate contact  233  is inserted in the through hole  236 . The contact leading end  243  is extended to be flush with a back face side opening of the through hole  236  or to a position short of the back face side opening of the through hole  236  by a predetermined length. According to a modification, the contact leading end  243  may be protruded by a predetermined length from the back face side opening of the through hole  236 . The through hole  236  is configured, for example, to cover the entire circumference of the contact leading end  243  of the substrate contact  233 . The through hole  236  is formed in such dimensions that the contact leading end  243  is arranged inside of the through hole  236  across a small clearance from an inner wall of the seal portion  235  or to be in close contact with or adhere to the inner wall of the seal portion  235 . The contact leading end  243  may be stuck to the seal portion  235  in the through hole  236  by using an adhesive or the like. 
     This embodiment describes a configuration that the seal member  231  is provided with respect to each of the substrate contacts  233 . According to a modification, one seal member  231  may be provided with respect to a plurality of the substrate contact  233 . According to another modification, a different number of substrate contacts  233  may be provided with respect to each of the seal members  231 . 
     The seal portion  235  is brought into contact with and pressed against a seed layer  530  on the substrate W as shown in  FIG. 27 . The entirety of (the leading end) of the seal portion  235  that covers and surrounds the contact leading end  243  is brought into contact with the seed layer  530  in such an area that the seed layer  530  is not covered with a resist  540 . In this drawing, a reference sign  510  indicates a bear substrate, and a reference sign  520  indicates another component such as an insulating layer. This configuration causes the entirety of the seal portion  235  in the periphery of the contact leading end  243  to come into contact with an equal height part on the substrate W (for example, with the surface of the seed layer  530  in an outer circumferential part of the substrate). This enhances the sealing property of the contact leading end  243  by the seal portion  235 . 
     The shapes and the dimensions of the seal portion  235  and the through hole  236  may be any arbitrary shapes and dimensions according to the shape and the dimensions of the contact leading end  243  of the substrate contact  233 . For example, the seal portion  235  and the through hole  236  may respectively be an elongated shape portion and a long hole in a slit-like shape that are respectively extended approximately parallel along the longitudinal member  211   a  as shown in  FIG. 7 . 
     The seal portion  237  is provided along an outer circumferential part on a front face of the seal member  231  and is configured to seal between the front plate  250  and the seal member  231  and to protect the substrate contact  233  from the plating solution as shown in  FIG. 11 . The seal portion  237  may be a projection provided integrally with the seal member  231  or may be configured by attaching a separate member such as an O-ring to the seal member body. 
     The through hole  238  is provided outside of the through hole  236  to penetrate from the front face side to the back face side. The shape and the dimensions of the through hole  238  may be any arbitrary shape and dimensions according to the shape and the dimensions of a base end portion of the substrate contact  233  (the projection  264  of the bus bar  260 ). For example, the through hole  238  may be a long hole extended approximately parallel to the through hole  236  as shown in  FIG. 7 . As shown in  FIG. 11 , the projection  264  of the bus bar  260  is made to pass through the through hole  238 , and an end face of the projection  264  of the bus bar  260  is exposed on a front face side of the substrate holder. It is preferable that the projection  264  of the bus bar  260  is protruded by a predetermined length from the front face of the seal member  231  such as to expose the end face of the projection  264 , in order to facilitate the connection with the substrate contact  233 . 
     As shown in  FIG. 9  and  FIG. 11 , the seal portion  239  is provided around the through hole  238  on a back face of the seal member  231  and is configured to seal between the seal member  231  and the bus bar  260  around the projection  264  and to protect the substrate contact  233  connected with the projection  264  from the plating solution. The seal portion  239  may be a projection provided integrally with the seal member  231  or may be configured by attaching a separate member such as an O-ring to the seal member body. 
     As shown in  FIG. 9  and  FIG. 11 , the protrusion  240  is provided outside of the through hole  238  to be protruded from the back face of the seal member  231 . The protrusion  240  serves as a support to abut against the second holding member  220  and serves as a pressure receiver to receive a pressing force from the second holding member  220  when the substrate W is held by the substrate holder  200 . Since the protrusion  240 , along with the seal portion  235 , serves as the pressure receiver to receive the pressing force from the second holding member  220 , it is preferable to form the protrusion  240  having the shape and the dimensions adequate for those of the seal portion  235 . For example, as shown in  FIG. 7  and  FIG. 9 , the protrusion  240  is formed in an elongated shape to be extended approximately parallel to the seal portion  235  and to have an approximately identical length with that of the seal portion  235 . The protrusion  240  is extended to pass through a through hole  267  of the bus bar  260  toward the second holding member  220  (not shown) placed on the back face side as shown in  FIG. 11 . The protrusion  240  serves as the pressure receiver to come into contact with the second holding member  220  and receive part of the pressing force of the second holding member  220  against the first holding member  210  when the substrate W is held by the first holding member  210  and the second holding member  220 . 
     As shown in  FIG. 7  and  FIG. 11 , the support plate  232  is placed between the seal member  231  and the substrate contact  233  to support the seal member  231  and the substrate contact  233 . The support plate  232  is formed to have a thickness that is equal to or slightly lower than the height of the projection  264  of the bus bar  260  protruded from the seal member  231 . The support plate  232  is provided with a through hole  242  that is formed substantially corresponding to the through hole  238  of the seal member  231  and that causes the projection  264  of the bus bar  260  to pass through. The through hole  242  may be slightly larger than the through hole  238 . 
     As shown in  FIG. 7 , the substrate contact  233  has the contact leading end  243  that comes into contact with the substrate W and is provided with one or a plurality of through holes  244  in its base end portion to cause screws  246  to pass through. The contact leading end  243  may have one or a plurality of leaf electrodes  243   a  or claw-like electrodes  243   a  as shown in  FIG. 7 . The base end portion of the substrate contact  233  is fixed to an end face of the projection  264  of the bus bar  260  by the screws  246  that pass through the through holes  244  and is electrically connected with the bus bar  260  as shown in  FIG. 11 . The contact leading end  243  is placed in the through hole  236  of the seal portion  235 , is arranged to pass through the through hole  263  of the bus bar  260  from the front face side toward the back face side in a state that the contact leading end  243  is covered with the seal portion  235 , and is positioned relative to and fixed to the bus bar  260 . 
     As shown in  FIG. 7 , the pressing plate  234  has through holes  245  formed to cause the screws  246  to pass through. The pressing plate  234  is arranged to hold the substrate contact  233 , in cooperation with the support plate  232  and the projection  264  of the bus bar  260 , and is placed to press the substrate contact  233  against the support plate  232  and the projection  264  as shown in  FIG. 11 . As illustrated in this drawing, in the state that the substrate contact  233  and the pressing plate  234  are placed on the support plate  232  and the projection  264 , the screws  246  that pass through the through holes  245  of the pressing plate  234  and the through holes  244  of the substrate contact  233  are screwed to the end face of the projection  264  of the sub bar  260 . This causes the substrate contact  233  to be fixed to the end face of the projection  264  of the bus bar  260  in the state that the substrate contact  233  is pressed against the support plate  232  and the projection  264  by the pressing plate  234 . This ensures electrical connection of the substrate contact  233  with the end face of the projection  264  of the bus bar  260 . 
     The bus bar  260  includes a holder portion  261  to mount the power feed module  230  and a thick wall portion  262  provided outside of the holder portion  261 . The holder portion  261  has the through hole  263  provided to cause the seal member  231  to pass through; the projection  264  provided to be connected with the substrate contact  233 ; screw holes  265  formed in the end face of the projection  264 ; a through hole  267  provided to cause the protrusion  240  of the seal member  231  to pass through; and through holes  268  provided to cause the pins  270  to pass through. The surface of the bus bar  260  other than the projection  264  that is to be connected with the substrate contact  233  is subjected to surface coating, such as PFA coating, which gives the electrical insulating properties and the corrosion resistance, so as to ensure the electric insulation and the corrosion resistance against the plating solution. 
     The through hole  263  is an open hole penetrating from the front face side to the back face side. The shape and the dimensions of the through hole  263  may be any arbitrary shape and dimensions according to the shape and the dimensions of the seal portion  235 . For example, the through hole  263  may be a slit-like long hole extended approximately parallel along the longitudinal member  211   a  as shown in  FIG. 7 . As shown in  FIG. 11 , the through hole  263  is configured to receive the seal portion  235  that covers the entire circumference of the contact leading end  243  of the substrate contact  233  and to position the contact leading end  243  and the seal portion  235 . 
     The projection  264  is formed outside of the through hole  263  to be approximately parallel to the through hole  263 . One or a plurality of screw holes  265  are formed in the end face of the projection  264  to receive the screws  246  screwed thereto for fixation of the substrate contact  233 . A seal groove  266  may be provided on the base end side around the projection  264  to receive the seal portion  239  of the seal member  231  therein. 
     The through hole  267  is formed outside of the projection  264  to be approximately parallel to the projection  264 . As shown in  FIG. 11 , the through hole  267  causes the protrusion  240  of the seal member  231  to pass through and to be protruded by a predetermined length toward the back face side of the bus bar  260 . The shape and the dimensions of the through hole  267  may be any arbitrary shape and dimensions according to the shape and the dimensions of the protrusion  240  of the seal member  231 . 
     As shown in  FIG. 6 , the through holes  268  are open holes provided to cause the pins  270  to pass through.  FIG. 7  illustrates only the part of the bus bar  260  corresponding to one power feed module  230  and thereby illustrates only part of the through holes  268 . 
     As shown in  FIG. 11 , the front plate  250  is placed on the front face side of the first holding member  210 . One or a plurality of recesses  252  are provided in a back face of the front plate  250  to receive the heads of the screws  246  used to fix the substrate contact  233 , as shown in  FIG. 10  and  FIG. 11 . As shown in  FIG. 6  and  FIG. 7 , the front plate  250  has through holes (female threads)  251  that respectively mate with male threaded portions of the pins  270  and is fixed such as to enclose the bus bar  260  and the like by screwing with the pins  270 . The through holes (female threads)  251  are through female threads screwed to the pins  270  as shown in  FIG. 6 .  FIG. 7  illustrates only part of the front plate  250  corresponding to one power feed module  230  and thereby illustrates only part of the through holes (female threads)  251 . The pin  270  includes a middle portion  272  (shown in  FIG. 14 ) and has a level difference from a leading end portion  271  to abut against the bus bar  260 . When the pins  270  are screwed into the female threads  251 , this configuration causes the components from the front plate  250  to the bus bar  260  to be integrated and causes the respective members of the power feed module  230  to be placed/fixed (integrated) according to a predetermined positional relationship between the front plate  250  and the bus bar  260 . 
     The configuration described above causes the contact leading end  243  of the substrate contact  233  to pass through the through hole  263  of the bus bar  260  and to be positioned in the state that the contact leading end  243  of the substrate contact  233  is covered with the seal portion  235 . The bus bar  260  serves to accurately position and hold the contact leading end  243  and the seal portion  235  relative to the substrate. There is accordingly no need to separately provide a seal holding member that positions and holds the seal portion  235 . This simplifies the configuration of the substrate holder  200 . As a result, this configuration enables the substrate contact  233  and the seal member  231  to be accurately positioned in a narrow location. As shown in  FIG. 27 , the width of the exposed area of the seed layer  530  on the outer circumference of the substrate, which the contact leading end  243  and the seal portion  235  come into contact with, becomes extremely small with advancement of devices. According to the embodiment, the contact leading end  243  is mounted to the bus bar  260  across the through hole  263  of the bus bar  260  in the state that the contact leading end  243  is covered with the seal portion  235 . This enables the contact leading end  243  to be accurately mounted to the bus bar  260  as a power feed pathway without requiring any additional structure. Additionally, the through hole  263  suppresses deformation of the contact leading end  243  and the seal portion  235  (in a direction parallel to the surface of the substrate) when the contact leading end  243  and the seal portion  235  are pressed against the substrate. This configuration thus ensures the sufficient sealing pressure and the contact pressure of the contact leading end  243  against the substrate. 
     The configuration described above causes the entire circumference of the contact leading end  243  of the substrate contact  233  to be closely covered with the seal portion  235 . This configuration effectively seals the contact leading end  243  of the substrate contact  233  and keeps the periphery of the contact leading end  243  dried. Furthermore, the contact leading end  243  is placed across a small clearance from or in close contact with an inner wall of the through hole  236  of the seal portion  235 , so that there is no space or very little space around the contact leading end  243  in the through hole  236 . This configuration accordingly reduces the entering amount of the plating solution to a very small quantity even when the plating solution enters the through hole  236 . This suppresses the bipolar phenomenon that makes the flow of shunt current in the substrate seed layer  530  and suppresses dissolution of the substrate seed layer  530 . Since there is no space or very little space around the contact leading end  243  in the through hole  236 , there is no air or very little air in the through hole  236 . Even when a little amount of the plating solution enters the through hole  236 , this configuration accordingly suppresses dissolution of the substrate seed layer caused by etching in the vicinity of a gas liquid interface due to the exposure and contact of the plating solution to and with the air (galvanic corrosion by dissolved oxygen concentration gradient). 
     In the configuration described above, the seal members  231  and the substrate contacts  233  are provided in the form of multiple modules (power feed modules  230 ). Even in the case of a large-sized substrate, this configuration further facilitates manufacture of the seal member  231  that effectively seals one or a plurality of substrate contacts  233  provided along the length of a side of the substrate. The seal members  231  and the substrate contacts  233  are arranged in the form of multiple modules (contact seal modules). This achieves the local seal structure to effectively seal the substrate contact  233  by means of the seal member  231  with respect to the length of each module. With reference to  FIG. 27 , the conventional substrate holders (for example, the substrate holders described in Japanese Unexamined Patent Publication No. 2018-40045 (Patent Document 1) and Japanese Unexamined Patent Publication No. 2019-7075 (Patent Document 2)) are configured such that a seal provided inside of a substrate contact is brought into contact with the surface of a resist  540 . The conventional configurations, however, require a large-sized seal member that uniformly covers the outer circumference of the substrate. 
     The configuration described above allows the substrate contact  233  and/or the seal member  231  to be individually replaced in the unit of each power feed module  230 . This facilitates maintenance and reduces the maintenance cost. 
     The configuration described above enables the power feed modules  230  to be placed according to the size of the substrate used and improves the versatility of the substrate holder. Omission of the power feed module  230  in a non-use area of the bus bar  260  (a part where the substrate is not brought into contact with) reduces the cost of the substrate holder. A dummy member may be placed in the part with omission of the power feed module  230  to shield the bus bar  260  from the plating solution and prevent the electric current from directly flowing from the plating solution to the bus bar  260 . The dummy member may be formed to have a shape and dimensions corresponding to one or a plurality of power feed modules  230  shown in  FIG. 7 . Like the power feed module  230 , the dummy member may be configured to be fixed to the projection  264  of the bus bar  260  by using the screws  246 , the pressing plate  234  and the support plate  232 . 
     (Substrate Holder Locking mechanism) 
       FIG. 12  is a perspective view illustrating close-up of the vicinity of the locking mechanism of the second holding member.  FIG. 13  is a back view illustrating close-up of the vicinity of the locking mechanism of the second holding member.  FIG. 14  is a sectional view taken along a line XIV-XIV in  FIG. 13  in a locked state.  FIG. 15  is a sectional perspective view taken along a line XV-XV in  FIG. 13  in the locked state.  FIG. 16  is a sectional perspective view taken along a line XVI-XVI in  FIG. 13  in the locked state.  FIG. 17  is a sectional perspective view taken along a line XVII-XVII in  FIG. 13  in the locked state. 
     The second holding member  220  includes the back plate  280 , the float plates  290  provided to be movable closer to and away from the back plate  280 , and the lock plates  300  provided to be slidable relative to the float plates  290  in an in-plane direction. 
     (Back Plate) 
     As shown in  FIGS. 2 to 4 , the back plate  280  is formed to have the dimensions and the shape to cover the substrate W and the parts of the longitudinal members  211   a  and  211   b  corresponding to the substrate W. As shown in  FIG. 17 , a substrate support plate  281  and a shock absorber  282  are provided on the first holding member  210 -side of the back plate  280 . The substrate support plate  281  is a single end-support (partially both end-support) plate member and is provided in a position corresponding to the outer circumferential part of the substrate W. The substrate support plate  281  is configured such that the shock absorber  282  is held between the back plate  280  and the substrate support plate  281 . The substrate support plate  281  works in cooperation with the shock absorber  282  to buffer the pressing force and to absorb a difference in thickness of the substrate (a thin substrate or a thick substrate) and warpage of the substrate. The shock absorber  282  is provided at a position corresponding to the seal portion  235  of the first holding member  210  and serves to buffer the pressing force received from the seal portion  235  and to absorb the difference in thickness of the substrate (the thin substrate or the thick substrate) and warpage of the substrate when the substrate is held by the substrate holder  200 . 
     (Float Plate) 
     As shown in  FIG. 4 , the float plates  290  are provided on respective sides of the back face of the back plate  280  along a left side and a right side of the substrate W corresponding to the longitudinal members  211   a  and  211   b  of the first holding member  210 . A spring  295  is provided between the back plate  280  and the float plate  290  as shown in  FIG. 14  and is configured to press the back plate  280  and the float plate  290  in directions away from each other. More specifically, the lock plate  300  is placed on one end of the spring  295  via the float plate  290 , and the back plate  280  is placed on the other end of the spring  295 . In other words, the spring  295  is provided between the lock plate  300  and the back plate  280  and is configured to press the lock plate  300  and the back plate  280  in the directions away from each other. The plurality of pins  270  are lock pins configured to lock the lock plate  300  and thereby lock the second holding member  220  to the first holding member  210 . When the second holding member  220  is mounted to the first holding member  210 , the pins  270  of the first holding member  210  penetrate inside of the springs  295  of the second holding member  220 , pass through the back plate  280  and the float plates  290 , and are locked to locking portions  304  of the lock plates  300 . In this state, the spring  295  is compressed to press the float plate  290  (the lock plate  300 ) and the back plate  280  such as to be separated from each other. This causes the back plate  280  to be pressed against the first holding member  210  and causes the substrate W to be pressed against the seal portion  235  by the back plate  280  when the substrate W is held. 
     As shown in  FIG. 14 , the back plate  280  has through holes  283  formed to cause the pins  270  to pass through, and the float plate  290  has through holes  294  formed to cause the pins  270  to pass through. The through hole  283  and the through hole  294  are provided at corresponding positions. The through hole  283  and the through hole  294  respectively have large diameter portions provided on the respective sides facing each other to place the spring  295  therein. These large diameter portions form a space to place the spring  295  therein. One end of the spring  295  abuts against a step at a boundary between the large diameter portion and a small diameter portion of the through hole  283 , and the other end of the spring  295  abuts against a step at a boundary between the large diameter portion and a small diameter portion of the through hole  294 . This configuration causes the spring  295  to press the back plate  280  and the float plate  290  (the lock plate  300 ) in the directions away from each other. 
     As shown in  FIG. 13  and  FIG. 16 , a plurality of guide pins  297  serve to fix the position of the float plate  290  in the in-plane direction relative to the back plate  280 . The float plate  290  is configured to be guided by the guide pins  297  and moved closer to and away from the back plate  280 . The guide pin  297  includes a pin  297   a,  a sleeve  297   b  and a stopper  297   c.  The pin  297   a  is configured to pass through a through hole provided in a bottom face of a recess  296  of the float plate  290  and to be fixed to the back plate  280  and is arranged such that its head is placed in the recess  296  of the float plate  290 . The sleeve  297  is placed around the pin  297   a  and is arranged such that the float plate  290  is guided in its axial direction along the outer circumference of the sleeve  297   b.  The stopper  297   c  is placed between the head of the pin  297   a  and the sleeve  297 . The stopper  297  is configured to abut against the bottom face of the recess  296  and to restrict the moving range of the float plate  290  away from the back plate  280 . 
     As shown in  FIG. 14 , the pin  270  includes a leading end portion  271  that is fixed to (screwed to according to this embodiment) the first holding member  210 , a middle portion  272  that has a larger diameter than the diameter of the leading end portion  271  and that passes through the back plate  280  and the float plate  290 , a base end portion  273  that has a smaller diameter than the diameter of the middle portion  272 , a flange  274  that is provided in the middle of the base end portion  273 , and a flange  275  that is provided at an edge of the base end portion  273 . The flange  274  constitutes a first locked portion to lock the substrate holder  200  in the state that the substrate is held. The flange  275  constitutes a second locked portion to semi-lock the substrate holder  200  in the state that the substrate is not held. The semi-locked state causes no load to be applied to the seal portion, for example, during storage of the substrate holder  200 .  FIG. 14  illustrates the locked state that the lock plate  300  is locked to the flange  274  of the pin  270  and that the substrate is held between the first holding member  210  and the second holding member  220 . 
     (Lock Plate) 
     As shown in  FIG. 4  and  FIG. 12 , the lock plates  300  are provided along the left side and the right side of the substrate W on the back faces of the float plates  290  corresponding to the longitudinal members  211   a  and  211   b  of the first holding member  210 . The lock plate  300  includes a base end portion  301 , guide portions  302 , guide grooves  303  provided in the guide portions  302 , locking portions  304  provided in the base end portion  301 , and biasing mechanisms  305 . The base end portion  301  is formed in a long shape corresponding to the longitudinal member  211   a  of the first holding member  210  and is provided with a plurality of locking portions  304  along a longitudinal direction thereof to be engaged with the plurality of pins  270  of the first holding member  210 . The locking portion  304  is provided to be engageable with the flange  274  or the flange  275  of the pin  270  as shown in  FIG. 14 . As shown in  FIG. 12 , the locking portion  304  is formed in a shape substantially corresponding to part of the circumferences (for example, half circumferences) of the flanges  274  and  275  of the pin  270  and has a step  304   a  that abuts against the bottom face of the flange  274  or the flange  275 . 
     As shown in  FIG. 12 , the guide portion  302  is extended from the base end portion  301  in a direction crossing the longitudinal direction (transverse direction) and has the guide groove  303  in a long hole shape extended in the transverse direction. According to the embodiment, the guide groove  303  is extended in a direction perpendicular to the longitudinal direction and is formed to penetrate the thickness of the guide portion  302 . As shown in  FIG. 15 , two guide pins  291  are engaged in the guide groove  303 . The guide groove  303  is configured such that the lock plate  300  is guided by these guide pins  291  and is moved on the float plate  290  in a transverse direction relative to the float plate  290 . The guide pin  291  includes a pin  292  that is fixed to the float plate  290  and a sleeve  293  that is mounted to the outer circumference of a base end portion of the pin  292  and has flanges on respective ends. The lock plate  300  is engaged between the flanges on the respective sides of the sleeve  293 . The flanges on the respective sides serve to define or fix the distance between the float plate  290  and the lock plate  300 . When the float plate  290  is moved by the spring  295  (shown in  FIG. 14 ) in a direction away from the back plate  180 , this configuration causes the lock plate  300  to move along with the float plate  290  in the direction away from the back plate  280 . When the lock plate  300  and/or the float plate  290  is moved against the biasing force of the spring  295  in a direction closer to the back plate  280 , this configuration causes the float plate  290  along with the lock plate  300  to move in the direction closer to the back plate  280 . 
     As shown in  FIG. 17 , the biasing mechanism  305  includes a spring  309  that is placed between a spring bearing  306  fixe to the lock plate  300  and a spring bearing  307  fixed to the float plate  290 . The spring bearing  306  may be provided with an engagement hole  308  to allow for engagement of a jig that is used to move the spring bearing  306 . The spring  309  serves to press the lock plate  300  against the float plate  290  in a direction that causes the locking portion  304  to engage with the pin  270  (outward). When the lock plate  300  is moved inward relative to the float plate  290  against the biasing force of the spring  309 , the locking portion  304  of the lock plate  300  is separated from the pin  270 , and the lock plate  300  is unlocked and released from the pin  270  (as shown in  FIG. 24 ). 
     (Semi-Locking) 
       FIG. 18  is a sectional perspective view corresponding to  FIG. 15  in the semi-locked state.  FIG. 19  is a sectional perspective view corresponding to  FIG. 16  in the semi-locked state.  FIG. 20  is a sectional perspective view corresponding to  FIG. 17  in the semi-locked state. The semi-locked state denotes a state that engages the substrate holder  200  without holding the substrate, for example, during storage of the substrate holder  200 . In the semi-locked state, the substrate holder  200  does not hold the substrate, and the first holding member  210  and the second holding member  220  are engaged with each other with applying no load to the seal portion  235 . As shown in  FIG. 19 , in the semi-locked state, the locking portion  304  of the lock plate  300  is engaged with the flange  275  at the end of the pin  270 . This semi-locked state increases the distance between the first holding member  210  and the second holding member  220 , compared with the distance in the locked state. As shown in  FIGS. 18 to 20 , this configuration enables the substrate holder  200  to be engaged in the state that the seal portion  235  is not in contact with the second holding member  220 . 
     (Local Seal Structure) 
       FIG. 21  is a sectional view taken along a line XXI-XXI in  FIG. 13 . As shown in  FIG. 21 , the pin  270  and the spring  295  are provided in the vicinity of the seal portion  235  along the outer circumference of the substrate W (along the left side and the right side of the substrate W in this illustrated example). This configuration accordingly enables the force of the pin  270  and the spring  295  pressing the substrate W via the back plate  280  to be transmitted to the seal portion  235  directly and by a short transmission pathway. This reduces a load applied to the substrate W by the pressing force of the pin  270  and the spring  295 . As a result, this configuration applies an appropriate pressing force to the seal portion  235  to seal the substrate contact  233 , while reducing the load applied to the substrate W. This configuration is especially effective for a large-sized substrate. In some cases, it may be difficult to apply a uniform force to the seal portion  235  over a long length of the large-sized substrate. On the other hand, the configuration of this embodiment implements a local seal structure that enables the force of the pin  270  and the spring  295  pressing the substrate W via the back plate  280  to be transmitted to the seal portion  235  directly and by the short transmission pathway, whereby to appropriately seal the seal portion  235  over the long distance, while reducing the load applied to the substrate W. 
     Furthermore, the protrusion  240  of the seal member  231  is configured such that the pin  270  and the spring  295  are placed between the protrusion  240  and the seal portion  235  in an outward direction of the substrate W. The outward direction of a substrate indicates a direction that is perpendicular to a side of the substrate or to a tangent of a periphery of the substrate and goes outward. In the case of a circular substrate, the outward direction denotes outward in a radial direction. In the case of a polygonal substrate, the outward direction denotes a direction that is perpendicular to a side and goes outward. This configuration causes the seal portion  235  and the protrusion  240  to serve as a pressure receiver that receives the pressing force of the pin  270  and the spring  295 . This establishes a local seal configuration or structure that effectively applies an appropriate biasing force to the seal portion  235  as a place to supply the power and to seal and further suppresses a load due to the biasing force from being applied to the entire substrate. The pressing force of the pin  270  and the spring  295  is received by the seal portion  235  on the inside of the pin  270  and the spring  295  and is received by the protrusion  240  on the outside of the pin  270  and the spring  295 . This is unlikely to cause deformation of the first holding member  210  (the longitudinal members  211   a  and  211   b ). Furthermore, the seal portion  235  and the protrusion  240  are respectively placed in the form of a plurality of divisions along a side of the substrate. This configuration thus ensures an appropriate seal pressure required to protect the substrate contact  233  from the plating solution. A known configuration of a conventional substrate holder uses an integral seal member provided along to be in contact with a side of the substrate holder. In some cases, however, it is difficult for the integral seal member to generate a uniform seal pressure along the side of the substrate. An excessive seal pressure is likely to be generated and to damage the substrate in some cases. 
     Moreover, the seal member  231  is provided in the form of modules as a plurality of divisions (as shown in  FIG. 7 ). Accordingly, the local seal structure achieved by the localized biasing force of a plurality of pins  270  and a plurality of springs  295  locally provided along the outer circumferential part of the substrate W cooperates with the local seal structure that seals the substrate contact  233  by means of the seal portion  235  with respect to each of the power feed modules to achieve a more localized seal. This further enhances the adaptability to the large-sized substrate. 
     (Modifications) 
       FIG. 22  is a sectional view illustrating a substrate holder according to a modification and is a sectional view corresponding to  FIG. 21 . As shown in  FIG. 22 , the spring  295  may be replaced by elastic elements  410  and  420 . The elastic elements  410  and  420  are provided respectively inside and outside of the pin  270  between the float plate  290  and the back plate  280  along the outer circumference of the substrate (along the left side and the right side of the substrate in this illustrated example). The elastic elements  410  and  420  are sequentially placed along the longitudinal direction of each of the longitudinal members  211   a  and  211   b  of the first holding member  210 . In the illustrated example, the elastic element  410  is placed at a position overlapping the seal portion  235 . In another example, both the elastic elements  410  and  420  may be arranged to be located outside of the substrate W. The elastic elements  410  and  420  may be provided in rod-like shapes, for example, obtained by cutting O-rings. The elastic elements  410  and  420  employed may be elastic elements made of any material such as a rubber or a resin and formed in any shape such as a rod-like shape or a tubular shape. 
     Each of the elastic elements  410  and  420  may be configured by aligning a plurality of pieces. The elastic elements  410  and  420  may be formed as an integrated ring-shaped member. According to a modification, an elastic element may be provided along the entire circumference of the substrate. In this case, the elastic element may be formed in an integral shape along the entire circumference of the substrate or may be comprised of multiple pieces. For example, a ring-shaped elastic element (formed in an integral shape or as multiple pieces) may be provided inside of the pin  270  to surround the entire circumference of the substrate and a rig-shaped elastic element (formed in an integral shape or as multiple pieces) may be provided outside of the pin  270  to surround the entire circumference of the substrate. In another example, the elastic elements  410  and  420  may be provided as an integral body, for example, an O-ring, to surround the individual pins  270 . 
     (Method of Mounting and Demounting Substrate) 
       FIGS. 23 to 26  are explanatory diagrams illustrating a method of mounting the substrate to the substrate holder.  FIG. 23  illustrates the substrate holder  200  in the state that the substrate is not held (for example, in the semi-locked state). From this state of  FIG. 23 , the lock plate  300  is slid inward relative to the float plate  290  to compress the springs  309  of the biasing mechanisms  305  and release the locking portions  304  of the lock plate  300  from the pins  270  as shown in  FIG. 24 . The second holding member  220  is subsequently detached from the first holding member  210  as shown in  FIG. 25 , and the substrate W is placed on the first holding member  210  as shown in  FIG. 26 . The second holding member  220  with the springs of the biasing mechanisms  305  in the compressed state is then placed on the longitudinal members  211   a  and  211   b  of the first holding member  210  with the substrate W placed thereon like the state of  FIG. 24  (with the substrate W placed in  FIG. 24 ). The float plate  290  (and/or the lock plate  300 ) is subsequently pressed down toward the back plate  280  to adjust the height of the locking portions  304  of the lock plate  300  such as to be engageable with the flanges  274  of the pins  270  (shown in  FIG. 14 ). The locking portions  304  of the lock plate  300  are then engaged with the flanges  274  of the pins  270  by releasing the compression of the springs of the biasing mechanisms  305 . This causes the substrate W to be held in the locked state by the substrate holder  200 . 
     A procedure of demounting the substrate slides the lock plate  300  inward relative to the float plate  290  such as to compress the springs  309  of the biasing mechanisms  305  of the substrate holder  200  with the substrate held thereby and releases the locking portions  304  of the lock plate  300  from the pins  270  (as shown in  FIG. 24 , with the substrate placed in  FIG. 24 ). The second holding member  220  is subsequently detached from the first holding member  210  (as shown in  FIG. 25 ), and the substrate W is demounted from the first holding member  210 . The second holding member  220  with the springs of the biasing mechanisms  305  in the compressed state is then placed on the longitudinal members  211   a  and  211   b  of the first holding member  210  without the substrate (like  FIG. 24 ). The float plate  290  (and/or the lock plate  300 ) is subsequently pressed down toward the back plate  280  to adjust the height of the locking portions  304  of the lock plate  300  such as to be engageable with the flanges  275  of the pins  270  (shown in  FIG. 14 ). The locking portions  304  of the lock plate  300  are then engaged with the flanges  275  of the pins  270  by releasing the compression of the springs of the biasing mechanisms  305 . This causes the substrate holder  200  to be in the semi-locked state. 
     (Other Embodiments) 
     (1) According to the embodiment described above, the substrate holder  200  is provided with the power feed devices along the two sides of the substrate W. According to another embodiment, the substrate holder  200  may be provided with power feed devices along the entire circumference of the substrate W. 
     (2) The configuration of providing the seal members  231  and the substrate contacts  233  in the form of multiple modules may be applied to a substrate holder for both-side plating. For example, a plurality of modules (power feed modules) including the seal members  231  and the substrate contacts  233  may be placed on both the first holding member and the second holding member. 
     (3) The above embodiment describes the locking mechanism (the pins  270 , the lock plate  300  and the biasing mechanism (the spring  295  or the elastic elements  410  and  420 )) of the substrate holder  200 , along with the seal member  231  in the form of the modules. The locking mechanism described above may be used for a conventional continuous integral seal or other any seals. 
       FIG. 28  is a schematic diagram illustrating an example of a substrate holder with the locking mechanism of the above embodiment applied to a continuous integral seal. This substrate holder  200 A is a face-down-type substrate holder and is used in a plating method (cup-type or cup-shaped plating method) that causes a surface to be plated (a plating surface) of a substrate W to be faced down and exposed to a plating solution Q. A first holding member  210 A includes holder bodies  260 A such as bus bars, pins  270 A fixed to the holder body  260 A, and substrate contacts  233 A and seal members  231 A held on the holder bodies  260 A. The pin  270 A has a flange  274  similar to the flange  274  of the embodiment described above. The pin  270 A may be provided with a flange  275  for semi-locking, in addition to the flange  274 . In this example, the seal member  231 A is provided inside of the substrate contact  233 A in the plane of the substrate W. No seal member is provided outside of the substrate contact  233 A. An external seal member configured to externally protect the substrate contact  233 A (for example, a seal member configured to seal between a second holding member  220 A and the holder body  260 A) may, however, be further provided on a needed basis according to the attitude of the substrate holder  200 A in a plating device. The second holding member  220 A includes a first plate  250 A, locking members  300 A, and biasing members (springs or elastic elements)  295 A placed between the first plate  250 A and the locking members  300 A and fixed to both the first plate  250 A and the locking members  300 A. The second holding member  220 A is laid over the first holding member  210 A with the substrate W placed thereon, and the locking members  300 A of the second holding member  220 A are locked by the pins  270 A of the first holding member  210 A. This compresses the biasing members  295 A and causes the biasing members  295 A to press the first plate  250 A and the substrate W against the seal members  231 A in the vicinity of the pins  270 A. This configuration has similar functions and advantageous effects to those of the pins and the biasing members (elastic elements) described above. The configuration illustrated in  FIG. 28  does not include float plates but may be provided additionally with float plates like the configuration of the embodiment described above (shown in  FIG. 12  to  FIG. 22 ). On the contrary, the float plates may be omitted from the configuration of the embodiment described above (shown in  FIG. 12  to  FIG. 22 ). 
     (4) According to the embodiment described above, the plurality of substrate contact  233  are attached to the bus bar  260 . According to another embodiment, one substrate contact (for example, a substrate contact extended over a predetermined length (one side, part of one side, the entire circumference or the like) on the outer circumference of the substrate) may be attached to one bus bar  260 . 
     (5) According to the embodiment described above, the continuous integral front plate is provided along the bus bars. According to another embodiment, individual front plates may be provided corresponding to individual power feed modules. In the latter case, each individual front plate serves in cooperation with the seal member  231  to protect the substrate contact  233  in each of the power feed modules. Accordingly, it may be regarded that each individual front plate is included as part of each individual power feed module. Each individual front plate may be made of the same material as that of the seal member  23 L 
     At least the following aspects are provided from the embodiments described above. 
     According to a first aspect, there is provided a substrate holder. The substrate holder comprises a contact assembly provided with a contact configured as an electric contact to come into contact with an outer circumferential part of a first face of a substrate, a seal member provided with a seal portion configured to cover a periphery of a leading end portion of the contact and to come into contact with the first face, and a holder body configured to hold the contact and the seal member; a first plate located on a second face side of the substrate and configured to hold the substrate between the contact assembly and the first plate; at least one first pin fixed to the holder body of the contact assembly, extended toward the second face side on outside of the substrate, and provided with a locked portion; a locking member placed on the second face side relative to the first plate and configured to be changeable or displaceable between a locked state/position and an unlocked state/position with respect to the locked portion of the first pin; and at least one first biasing member placed between the locking member and the first plate along the outer circumferential part of the substrate such as to separate the locking member and the first plate from each other and compressed between the locking member and the first plate in the locked state to bias the first plate toward the contact assembly. 
     According to this aspect, the first pin and the first biasing member that define a force of biasing the first plate against the contact assembly are provided in the outer circumferential part of the substrate. This configuration enables the biasing force of the first biasing member to be applied directly and by a short transmission pathway to the outer circumferential part of the substrate. This accordingly enables the force of pressing the seal portion to be transmitted from the first biasing member to the substrate directly and by a short transmission pathway. This configuration achieves a local seal structure that applies an appropriate biasing force to any location where the electric power is to be fed/any location to be sealed. The configuration that a plurality of first pins and a plurality of first biasing members (or one or a plurality of first biasing members having a length along the outer circumference of the substrate) are provided along the outer circumferential part of the substrate suppresses a load caused by the biasing force from being applied to the entire substrate. As a result, this configuration enables the seal portion to be pressed and sealed by an appropriate pressing force, while suppressing the load from being applied to the entire substrate. 
     Moreover, the configuration of this aspect causes the periphery of the leading end portion of the contact (substrate contact) to be covered by the seal member. This configuration effectively seals the substrate contact and keeps the periphery of the leading end portion of the substrate contact dried. Furthermore, the periphery of the leading end portion of the substrate contact is covered by the seal member, so that there is no space or very little space in the periphery of the leading end portion of the substrate contact. This configuration accordingly reduces the entering amount of the plating solution to a very small quantity even when the plating solution slightly enters the periphery of the leading end portion of the substrate contact. This suppresses the bipolar phenomenon that makes the flow of shunt current in a substrate seed layer and suppresses dissolution of the substrate seed layer. Since there is no space or very little space in the periphery of the leading end portion of the substrate contact, there is no air or very little air in the periphery of the leading end portion of the substrate contact. Even when a little amount of the plating solution enters the periphery of the leading end portion of the substrate contact (for example, a through hole of a seal portion), this configuration accordingly suppresses dissolution of the substrate seed layer caused by etching in the vicinity of a gas liquid interface due to the exposure and contact of the plating solution to and with the air (galvanic corrosion by dissolved oxygen concentration gradient). 
     In a substrate configured to define a distance between two members that are provided to cover the entirety or the whole outer circumference of a substrate by using the two members and a clamp structure provided near to an outer circumference (in the vicinity of the outer circumference) of the two members, all the deformations of the members constituting the substrate holder and the warpage of the substrate are likely to cause a variation in crushing amount of the seal (=seal pressure). The clamp structure provided in the vicinity of the outer circumference of the two members fails to transmit the force of pressing the seal portion directly and by a short transmission pathway and is significantly and adversely affected by, for example, deformations of the members constituting the substrate holder. According to the configuration of this aspect, on the other hand, the sealing force is generated by at least one first pin and at least one first biasing member on the outside of the substrate. This configuration reduces the influence of the deformations of the members constituting the substrate holder on the sealing force. This accordingly enables the force of pressing the seal portion to be transmitted from the first biasing member to the substrate directly and by a short transmission pathway and thereby enables the sealing force to be steadily generated at every arbitrary location where the electric power to be fed/every arbitrary location to be sealed. The configuration that a plurality of first pins and a plurality of first biasing members (or one or a plurality of first biasing members having a length along the outer circumference of the substrate) are provided along the outer circumferential part of the substrate suppresses a load caused by the biasing force from being applied to the entire substrate. As a result, this configuration enables the seal portion to be pressed and sealed by an appropriate pressing force, while suppressing the load from being applied to the entire substrate. Furthermore, this configuration enables an appropriate sealing force to be generated along the warpage of the substrate at every arbitrary location where the electric power to be fed/every arbitrary location to be sealed. 
     According to a second aspect, there is provided a substrate holder. The substrate holder comprises a contact assembly provided with a contact configured as an electric contact to come into contact with an outer circumferential part of a first face of a substrate, a seal member provided with a seal portion configured to come into contact with the first face on inside of the contact, and a holder body configured to hold the contact and the seal member; a first plate located on a second face side of the substrate and configured to hold the substrate between the contact assembly and the first plate; a plurality of first pins, each being fixed to the holder body of the contact assembly, extended toward the second face side on outside of the substrate, and provided with a locked portion; a locking member placed on the second face side relative to the first plate and configured to be changeable or displaceable between a locked state/position and an unlocked state/position with respect to the locked portion of the first pin; and a plurality of first biasing members provided along the outer circumferential part of the substrate, placed between the locking member and the first plate such as to separate the locking member and the first plate from each other, and compressed between the locking member and the first plate in the locked state to bias the first plate toward the contact assembly. 
     According to this aspect, the first pins and the first biasing members that define a force of biasing the first plate against the contact assembly are provided in the outer circumferential part of the substrate. This configuration enables the biasing force of the first biasing members to be applied directly and by a short transmission pathway to the outer circumferential part of the substrate. This accordingly enables the force of pressing the seal portion to be transmitted from the first biasing members to the substrate directly and by the short transmission pathway. This configuration achieves a local seal structure that applies an appropriate biasing force to any location where the electric power is to be fed/any location to be sealed. Furthermore, the plurality of first pins and the plurality of first biasing members are provided along the outer circumferential part of the substrate. This configuration suppresses a load caused by the biasing force from being applied to the entire substrate. As a result, this configuration enables the seal portion to be pressed and sealed by an appropriate pressing force, while suppressing the load from being applied to the entire substrate. 
     In a substrate holder configured to define a distance between two members that are provided to cover the entirety or the whole outer circumference of a substrate by using the two members and a clamp structure provided near to an outer circumference (in the vicinity of the outer circumference) of the two members, all the deformations of the members constituting the substrate holder and the warpage of the substrate are likely to cause a variation in crushing amount of the seal (=seal pressure). The clamp structure provided in the vicinity of the outer circumference of the two members fails to transmit the force of pressing the seal portion directly and by a short transmission pathway and is significantly and adversely affected by, for example, deformations of the members constituting the substrate holder. According to the configuration of this aspect, on the other hand, the sealing force is generated by the plurality of first pins and the plurality of first biasing members on the outside of the substrate. This configuration reduces the influence of the deformations of the members constituting the substrate holder on the sealing force. This accordingly enables the force of pressing the seal portion to be transmitted from the first biasing members to the substrate directly and by a short transmission pathway and thereby enables the sealing force to be steadily generated at every arbitrary location where the electric power to be fed/every arbitrary location to be sealed. Furthermore, the plurality of first pins and the plurality of first biasing members are provided along the outer circumferential part of the substrate. This configuration suppresses a load caused by the biasing force from being applied to the entire substrate. As a result, this configuration enables the seal portion to be pressed and sealed by an appropriate pressing force, while suppressing the load from being applied to the entire substrate. Furthermore, this configuration enables an appropriate sealing force to be generated along the warpage of the substrate at every arbitrary location where the electric power to be fed/every arbitrary location to be sealed. 
     According to a third aspect, the substrate holder of either the first aspect or the second aspect may further comprise a second plate placed relative to the first plate. The first biasing member may be placed between the first plate and the second plate such as to separate the first plate and the second plate from each other. The locking member may be locked to the locked portion of the first pin on an opposite side of the second plate to the first plate. 
     The configuration of this aspect enables the first biasing member to be held in a stable attitude between the first plate and the second plate and enables a stable biasing force to be applied from the first biasing member to the first plate. 
     According to a fourth aspect, the substrate holder of the third aspect may further comprise a second biasing member placed between the locking member and the second plate. The locking member may be biased by the second biasing member to the locked state or to the unlocked state. 
     At a normal lock position biased to the locked state by the second biasing member, the configuration of this aspect does not require application of any external force/energy to keep the locking member in the locked state. This configuration accordingly requires application of an external force/energy against the biasing force of the second biasing member with a view to releasing the lock only at the time of mounting and demounting the substrate, while not requiring any external force/energy to keep the locked state during holding the substrate. This achieves energy saving. At a normal release position biased to the unlocked state by the second biasing member, the configuration of this aspect does not require application of any external force/energy to release the lock. 
     According to a fifth aspect, the substrate holder of either the third aspect or the fourth aspect may further comprise a second pin fixed to the second plate. The locking member may include a first guide hole which the second pin is inserted in. The locking member may be guided by the second pin along a surface of the second plate to be moved between the locked state and the unlocked state. 
     The configuration of this aspect enables the locking member to be moved along the surface of the second plate between the locked state and the unlocked state in a stable attitude. 
     According to a sixth aspect, in the substrate holder of either the third aspect or the fourth aspect, the locking member may be moved along with the second plate to become closer to and away from the first plate. The first plate may include one of a third pin and a second guide hole which the third pin is inserted in, and the second plate may include the other of the third pin and the second guide hole. The first and second plates are guided by the third pin to be moved closer to and away from each other. 
     The configuration of this aspect enables the first plate and the second plate to approach to and separate from each other in a stable attitude. 
     According to a seventh aspect, in the substrate holder of any one of the first aspect to the sixth aspect, at least part of the first biasing member may be located outside of the substrate. 
     In the configuration of this aspect, the first biasing member is placed at a position close to a sealing location of the outer circumferential part of the substrate. This enables an appropriate biasing force to be applied directly and by a short transmission pathway to any location where the electric power is to be fed/any location to be sealed. This suppresses a load caused by the biasing force from being applied to the other part of the substrate or to the entire substrate. 
     According to an eighth aspect, in the substrate holder of the seventh aspect, the first biasing member may have a spring that is placed in a periphery of the at least one first pin. For example, the spring may be arranged coaxially with the first pin. An elastic element (for example, a tubular elastic element) placed in the periphery of the first pin may be used in place of the spring. 
     The configuration of this aspect causes the first pin and the spring that define the biasing force applied to the substrate and the seal portion to be arranged close to the seal portion and to be arranged close to each other or coaxially. This configuration effectively suppresses deformation and/or reduces a bending moment of the members between the first pin, the spring, and the seal portion. 
     According to a ninth aspect, in the substrate holder of the seventh aspect, the first biasing member may include an elastic element placed on an inner side of the first pin and/or an elastic element placed on an outer side of the first pin in an outward direction of the substrate. The elastic member employed may be an elastic element made of any material such as a rubber or a resin and formed in any shape such as a rod-like shape or a tubular shape. The outward direction of the substrate indicates a direction that is perpendicular to a side of the substrate or to a tangent of a periphery of the substrate and goes outward. In the case of a circular substrate, the outward direction denotes outward in a radial direction. In the case of a polygonal substrate, the outward direction denotes a direction that is perpendicular to a side and goes outward. 
     The configuration of this aspect causes the first pin and the elastic element that define the biasing force applied to the substrate and the seal portion to be arranged close to the seal portion and to be arranged close to each other. This configuration effectively suppresses deformation and/or reduces a bending moment of the members between the first pin, the elastic element and the seal portion. Furthermore, the configuration of providing a common elastic element for a plurality of first pins reduces the number of the components. 
     According to a tenth aspect, in the substrate holder of any one of the first aspect to the ninth aspect, at least part of the first biasing member may be arranged to overlap with the seal portion. 
     The configuration of this aspect enables the biasing force to be transmitted from the first biasing member to the seal portion more directly and by a shorter transmission pathway. 
     According to an eleventh aspect, in the substrate holder of any one of the first aspect to the tenth aspect, the seal member may further include a protrusion that is protruded toward the first plate on an outer side of the seal member, and the first pin may be placed on an outer side of the seal portion and on an inner side of the protrusion in an outward direction of the substrate. 
     The configuration of this aspect causes the seal portion and the protrusion respectively placed on the respective sides of the first pin to receive the pressing force from the first plate in the outward direction of the substrate. This configuration enables a more stable biasing force to be applied to any location where the electric power is to be fed/any location to be sealed. This establishes a more stable local seal structure, while suppressing a load caused by the biasing force from being applied to the other part of the substrate or to the entire substrate. 
     According to a twelfth aspect, in the substrate holder of any one of the first aspect to the eleventh aspect, the locked portion of the first pin may comprise a first locked portion configured to lock the first plate and the contact assembly in a state that a distance between the first plate and the holder body of the contact assembly is equal to a first distance; and a second locked portion configured to lock the first plate and the contact assembly in a state that the distance between the first plate and the holder body of the contact assembly is equal to a second distance that is larger than the first distance. 
     According to the configuration of this aspect, locking by the first locked portion enables the substrate holder to hold the substrate in the state that the substrate is appropriately sealed by the seal portion. Additionally, locking by the second locked portion enables the substrate holder without holding the substrate to be stored in the locked state without applying a load to the seal portion. 
     According to a thirteenth aspect, in the substrate holder of any one of the first aspect to the twelfth aspect, the contact assembly may have a plurality of contact seal modules, and each of the contact seal modules may include at least one contact and the seal member provided corresponding to the at least one contact. 
     According to this aspect, the seal member is divided for each group of the contacts. This configuration achieves a more local seal structure. This configuration enables the contact to be sealed more effectively by the seal portion with regard to each module. Each contact seal module may be arranged along the warpage of the substrate. This configuration enables the seal portion to be compressed by an appropriate force with regard to each contact seal module. This achieves a more local seal structure. 
     According to a fourteenth aspect, in the substrate holder of the thirteenth aspect, at least one first pin may be provided for each of the contact seal modules. 
     The configuration of this aspect enables the more appropriate biasing force to be received with regard to each contact seal module. 
     According to a fifteenth aspect, in the substrate holder of the thirteenth aspect, at least one first pin and at least one first biasing member may be provided for each of the contact seal modules. 
     The configuration of this aspect enables the more appropriate biasing force to be received with regard to each contact seal module. 
     According to a sixteenth aspect, the substrate holder of either the fourteenth aspect or the fifteenth aspect may further comprise the first pin placed between adjacent contact seal modules. 
     The configuration of this aspect places the first pin between the contact seal modules and thereby does not require any structure of receiving the first pin to be provided inside of the contact seal module. This facilitates the layout of the first pin. 
     According to a seventeenth aspect, in the substrate holder of any one of first aspect to the sixteenth aspect, the holder body may have a bus bar that is electrically connected with the contact. 
     According to this aspect, the bus bar is used as the holder body to fix the first pin. This simplifies the configuration of the substrate holder and/or reduces the size of the substrate holder. 
     According to an eighteenth aspect, in the substrate holder of the seventeenth aspect, the holder body may further include a third plate attached to the bus bar on a side opposite to the first plate. 
     The configuration of this aspect causes the bus bar to be shielded by the third plate and prevents the electric current from directly flowing from a plating solution to the bus bar. Moreover, this configuration causes the first pin to be fixed to the bus bar and the third plate and thereby further stabilizes the fixation of the first pin. 
     According to a nineteenth aspect, in the substrate holder of any one of the first aspect to the eighteenth aspect, the substrate may be in a polygonal shape, and the contact and the seal member may be provided on opposed two sides of the substrate. 
     This aspect simplifies the configuration of the substrate holder and reduces the weight of the substrate holder. 
     According to a twentieth aspect, there is provided a plating apparatus, which comprises the substrate holder of any one of the first aspect to the nineteenth aspect; and a plating device configured to plate a substrate held by the substrate holder. The configuration of this aspect has similar functions and advantageous effects to those of the first to the nineteenth aspects described above and can improve the plating quality. 
     Although the embodiments of the present invention have been described based on some examples, the embodiments of the invention described above are presented to facilitate understanding of the present invention, and do not limit the present invention. The present invention can be altered and improved without departing from the subject matter of the present invention, and it is needless to say that the present invention includes equivalents thereof. In addition, it is possible to arbitrarily combine or omit respective constituent elements described in the claims and the specification in a range where at least a part of the above-mentioned problem can be solved or a range where at least a part of the effect is exhibited. 
     The present application claims a priority to Japanese patent application No. 2019-225776 filed on Dec. 13, 2019. The entire disclosure of Japanese patent application No. 2019-225776 filed on Dec. 13, 2019, including the specification, claims, drawings and summary is incorporated herein by reference in its entirety. The entire disclosure of Japanese Unexamined Patent Publication No. 2018-40045 (Patent Document 1), Japanese Unexamined Patent Publication No. 2019-7075 (Patent Document 2), Japanese Unexamined Patent Publication No. 2008-133526 (Patent Document 3), and Japanese Unexamined Patent Publication No. 2007-46154 (Patent Document 4) including the specification, claims, drawings and summary is incorporated herein by reference in its entirety. 
     REFERENCE SIGNS LIST 
     
         
           39  plating device 
           100  plating apparatus 
           200  substrate holder 
           210  first holding member 
           211   a,    211   b  longitudinal members 
           212 ,  213  transverse members 
           215  rail 
           216  arm 
           217  external connecting portion 
           218   a,    218   b  bus bars 
           220  second holding member 
           230  power feed module 
           231  seal member 
           232  support plate 
           233  substrate contact 
           234  pressing plate 
           235  seal portion 
           236  through hole 
           237  seal portion 
           238  through hole 
           239  seal portion 
           240  protrusion 
           242  through hole 
           243  contact leading end 
           243   a  leaf electrode 
           250  front plate 
           251  through hole (female thread) 
           260  bus bar 
           263  through hole 
           264  projection 
           268  through hole 
           270  pin 
           274 ,  275  flanges 
           280  back plate 
           281  substrate support plate 
           282  shock absorber 
           290  float plate 
           291  guide pin 
           295  spring 
           297  guide pin 
           300  lock plate 
           301  base end portion 
           302  guide portion 
           303  guide groove 
           304  locking portion 
           304   a  step 
           305  biasing mechanism 
           309  spring 
           410 ,  420  elastic elements