U.S. patent application number 15/140869 was filed with the patent office on 2016-08-18 for surface treatment system and workpiece-holding jig.
This patent application is currently assigned to ALMEX PE INC.. The applicant listed for this patent is ALMEX PE INC.. Invention is credited to Katsumi ISHII, Tomohiro NODA, Shigeyuki WATANABE.
Application Number | 20160237588 15/140869 |
Document ID | / |
Family ID | 47355286 |
Filed Date | 2016-08-18 |
United States Patent
Application |
20160237588 |
Kind Code |
A1 |
NODA; Tomohiro ; et
al. |
August 18, 2016 |
SURFACE TREATMENT SYSTEM AND WORKPIECE-HOLDING JIG
Abstract
A surface treatment system includes a surface treatment tank, a
first guide rail and a second guide rail that extend at a position
offset from a position over the upper opening of the surface
treatment tank, and a plurality of transfer jigs that respectively
hold a workpiece and are supported by the first guide rail and the
second guide rail. The transfer jig includes a horizontal arm
section, a first guide target section that is guided by the first
guide rail, a second guide target section that is guided by the
second guide rail, and a vertical arm section that is suspended
from the horizontal arm section at a position between the first
guide target section and the second guide target section, and holds
the workpiece.
Inventors: |
NODA; Tomohiro;
(Utsunomiya-shi, JP) ; WATANABE; Shigeyuki;
(Utsunomiya-shi, JP) ; ISHII; Katsumi;
(Shioya-machi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ALMEX PE INC. |
Kanuma-shi |
|
JP |
|
|
Assignee: |
ALMEX PE INC.
Kanuma-shi
JP
|
Family ID: |
47355286 |
Appl. No.: |
15/140869 |
Filed: |
April 28, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13537862 |
Jun 29, 2012 |
9346632 |
|
|
15140869 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05C 3/02 20130101; C25D
17/005 20130101; B65G 49/0477 20130101; C25D 17/06 20130101; C25D
17/02 20130101; B05C 3/09 20130101; B05C 3/10 20130101; C25D 17/08
20130101 |
International
Class: |
C25D 17/08 20060101
C25D017/08; C25D 17/02 20060101 C25D017/02; B65G 49/04 20060101
B65G049/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2011 |
JP |
2011-145987 |
Mar 22, 2012 |
JP |
2012-065564 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. A workpiece-holding jig that holds a sheet-like rectangular
workpiece in a solution contained in a treatment tank, the
workpiece-holding jig comprising: a plurality of first chuck
members that hold a first side of the rectangular workpiece; a
plurality of second chuck members that hold a second side of the
rectangular workpiece, the second side being opposite to the first
the side in a first direction; and a frame-like member that is
disposed to surround the rectangular workpiece, and supports the
plurality of first chuck members and the plurality of second chuck
members, the frame-like member including: a first guide section
that guides the plurality of first chuck members so that the
plurality of first chuck members are movable along the first
direction; and a first biasing member that biases the plurality of
first chuck members in one direction in which the plurality of
first chuck members move away from the plurality of second chuck
members along the first direction.
8. The workpiece-holding jig as defined in claim 7, the frame-like
member further including: a second guide section that guides the
plurality of second chuck members so that the plurality of second
chuck members are movable along the first direction; and a second
biasing member that biases the plurality of second chuck members in
a direction in which the plurality of second chuck members move
away from the plurality of first chuck members along the first
direction.
9. The workpiece-holding jig as defined in claim 7, the frame-like
member including a stationary plate, and a movable plate that is
disposed to overlap the stationary plate, the first guide section
having a long hole that is formed in one of the stationary plate
and the movable plate, and extends along the first direction, and a
shaft that is formed on another of the stationary plate and the
movable plate, and is inserted into the long hole, and the first
biasing member pressing and biasing the movable plate in the one
direction relative to the stationary plate.
10. The workpiece-holding jig as defined in claims 7, each of the
plurality of first chuck members and the plurality of second chuck
members including: a stationary member that comes in contact with a
first side of the workpiece; and a movable member that is disposed
at a position opposite to the stationary member so as to come in
and out of contact with a second side of the workpiece, and is
pressed against the second side, the movable member including: a
driven element that is driven when the movable member is not
pressed against the second side; a pressed element that is always
pressed toward the stationary member when the driven element is not
driven; and a pressing element that is formed in a shape of a thin
plate at a free end of the pressed element.
11. (canceled)
12. A workpiece-holding jig that vertically holds a sheet-like
rectangular workpiece in a solution contained in a treatment tank,
and sets the rectangular workpiece as a cathode, the
workpiece-holding jig comprising: a frame-like member that is
disposed to surround the rectangular workpiece; a plurality of
conductive first chuck members that are supported by the frame-like
member, and hold an upper side of the rectangular workpiece; a
plurality of conductive second chuck members that are supported by
the frame-like member in a state in which the plurality of second
chuck members are electrically insulated from the plurality of
first chuck members, and hold a lower side of the rectangular
workpiece; a first current-carrying section that supplies current
to the plurality of first chuck members; and a second
current-carrying section that supplies current to the plurality of
second chuck members.
13. The workpiece-holding jig as defined in claim 12, the
frame-like member including: a conductive upper frame member that
supports the plurality of first chuck members; a conductive lower
frame member that supports the plurality of second chuck members;
two insulating members that are provided on either end of the upper
frame member; and two conductive vertical frame members, an upper
end of the two vertical frame members being respectively supported
by the two insulating members, and a lower end of the two vertical
frame members being connected to either end of the lower frame
member, the first current-carrying section supplying current to the
upper frame member, and the second current-carrying section
supplying current to the two vertical frame members.
14. The workpiece-holding jig as defined in claim 13, further
comprising: a common current-carrying section that supports the
frame-like member via part of the first current-carrying section,
and supplies current to the first current-carrying section and the
second current-carrying section.
15. The workpiece-holding jig as defined in claim 14, the first
current-carrying section including: an insulating section that is
secured on the common current-carrying section; a conductive
connection section that connects the insulating section and the
upper frame member; and at least one upper frame current-carrying
cable that connects the common current-carrying section and the
connection section, and the second current-carrying section
including a first vertical frame current-carrying cable and a
second vertical frame current-carrying cable that connect the
common current-carrying section and the two vertical frame
members.
16. The workpiece-holding jig as defined in claim 15, the
connection section including: a first vertical arm section and a
second vertical arm section that connect the insulating section and
the upper frame member; a first protrusion section that protrudes
from the first vertical arm section; and a second protrusion
section that protrudes from the second vertical arm section, and
the at least one upper frame current-carrying cable including a
first upper frame current-carrying cable that connects the common
current-carrying section and the first protrusion section, and a
second upper frame current-carrying cable that connects the common
current-carrying section and the second protrusion section.
17. The workpiece-holding jig as defined in claim 14, a resistance
of a current path from the common current-carrying section to the
upper frame member and a resistance of a current path from the
common current-carrying section to the lower frame member being set
to be substantially equal.
18. The workpiece-holding jig as defined in claim 16, each of the
two insulating members including a guide section that slidingly
guides an upper end of either of the two vertical frame members in
a vertical direction.
19. The workpiece-holding jig as defined in claim 18, further
comprising: a biasing member that biases either of the two vertical
frame member that is slidingly guided by the guide section in a
downward direction.
20. The workpiece-holding jig as defined in claim 19, a lower end
of the biasing member being secured on either of the two vertical
frame members that is slidingly guided by the guide section, an
upper end of the biasing member being secured on a conductive
stationary member that is supported by either of the two insulating
members, and either of the first and second vertical frame
current-carrying cables being connected to the stationary
member.
21. (canceled)
22. (canceled)
23. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority from and is a divisional
application of U.S. patent application Ser. No. 13/537,862, filed
Jun. 29, 2012, and incorporated by reference herein, which claims
priority from Japanese Patent Application No. 2011-145987, filed on
Jun. 30, 2011, and Japanese Patent Application No. 2012-65564,
filed on Mar. 22, 2012.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a surface treatment system
(e.g., serial (continuous) plating system) and a workpiece-holding
jig.
[0004] 2. Description of the Related Art
[0005] A serial plating system that serially (continuously)
transfers workpieces (e.g., circuit boards) in a plating tank has
been known as a surface treatment system such as an electroplating
system that plates the surface of a workpiece. The workpiece is
suspended from a transfer jig that is transferred along a feed
rail, and serially transferred in the plating tank while current is
supplied to the workpiece from the feed rail via the transfer jig.
Anodes are disposed in the plating tank on either side of a
transfer path of the workpiece (i.e., cathode). An electric field
is formed between the cathode and the anode to electrolyze the
plating solution and plate the surface of the workpiece.
[0006] A structure has been known in which the feed rail extends in
parallel to the longitudinal direction of the plating tank at a
position offset from a position above the plating tank (see
Japanese Patent No. 3591721) instead of disposing the feed rail
above the plating tank (see Japanese Patent No. 3025254). This
makes it possible to prevent a situation in which dust that occurs
when the transfer jig slides on the feed rail is mixed into the
plating tank.
[0007] A surface treatment system such as a serial plating system
is configured so that a workpiece is suspended from a
workpiece-holding jig, and serially transferred in a solution
contained in a surface treatment tank. The workpiece-holding jig
normally holds the upper side (end) of the workpiece in a suspended
state (see JP-A-2009-132956).
[0008] The workpiece-holding jig also has a function of setting the
workpiece as a cathode with respect to an anode disposed in the
surface treatment tank. An electric field is formed between the
cathode and the anode to electrolyze the plating solution and plate
the surface of the workpiece. Therefore, a chuck member that holds
the upper side (end) of the workpiece is formed using a conductive
member, and the workpiece is set as the cathode through the
workpiece-holding jig.
[0009] In Japanese Patent No. 3025254, the transfer jig and the
workpiece are suspended and stably supported right under the feed
rail. On the other hand, when disposing the feed rail at a position
offset from a position above the plating tank (see Japanese Patent
No. 3591721), the center of gravity of the transfer jig and the
workpiece is offset from the perpendicular line that passes through
the feed rail, so that an unnecessary moment acts on the transfer
jig.
[0010] Therefore, the transfer jig disclosed in Japanese Patent No.
3591721 has a complex structure as compared with the jig disclosed
in Japanese Patent No. 3025254 in order to suppress a problem due
to an unnecessary moment. For example, Japanese Patent No. 3591721
provides a removal prevention rail that prevents removal of the
transfer jig on the side surface of the feed rail. Therefore, the
structure of the feed rail also becomes complex.
[0011] If the workpiece is tilted to intersect the transfer
direction when viewed from above when the workpiece that is held by
the transfer jig advances in the treatment solution, the workpiece
may be bent due to the treatment solution, so that the commercial
value of the workpiece may be impaired. If a vertical motion of the
transfer jig occurs when the workpiece that is held by the transfer
jig advances in the treatment solution, the electrical contact
between the feed rail and the transfer jig may be impaired, so that
the plating quality may deteriorate. In order to prevent such a
situation, it is necessary to employ a complex structure for
stabilizing the travel of the transfer jig.
[0012] It was also found that it is difficult to ensure the
in-plane uniformity of the surface treatment of the workpiece when
providing only a current-carrying path that is connected to the
upper side (end) of the workpiece (see JP-A-2009-132956).
SUMMARY OF THE INVENTION
[0013] Several aspects of the invention may provide a surface
treatment system that can support a transfer jig in a very stable
manner by improving the structure of a transfer jig that is
transferred along a rail disposed at a position offset from a
position above a surface treatment tank.
[0014] Several aspects of the invention may provide a
workpiece-holding jig that can transfer a workpiece without causing
breakage due to liquid pressure or the like even if the workpiece
is very thin.
[0015] Several aspects of the invention may provide a surface
treatment system in which a feed rail is provided separately from a
guide rail, and a feed target section that receives current from
the feed rail always comes in contact with the feed rail at a
moderate contact pressure independently of the transfer state of a
transfer jig.
[0016] Several aspects of the invention may provide a
workpiece-holding jig and a surface treatment system that can
improve the in-plane uniformity of the current distribution of a
workpiece, and can further improve the surface treatment quality of
the workpiece.
[0017] (1) According to one aspect of the invention, there is
provided a surface treatment system comprising:
[0018] a surface treatment tank that holds a treatment solution,
and has an upper opening;
[0019] a first guide rail and a second guide rail that extend along
a first direction that is parallel to a longitudinal direction of
the surface treatment tank at a position offset from a position
over the upper opening of the surface treatment tank; and a
plurality of transfer jigs that respectively hold a workpiece that
is immersed in the treatment solution contained in the surface
treatment tank, and are supported by the first guide rail and the
second guide rail, each of the plurality of transfer jigs
including: [0020] a horizontal arm section that extends along a
second direction that intersects the first direction;
[0021] a first guide target section that is supported on one end of
the horizontal arm section, and is guided by the first guide
rail;
[0022] a second guide target section that is supported on another
end of the horizontal arm section, and is guided by the second
guide rail; and
[0023] a vertical arm section that is suspended from the horizontal
arm section at a position between the first guide target section
and the second guide target section, and holds the workpiece.
[0024] Specifically, each transfer jig has a doubly supported beam
configuration in which the first guide target section and the
second guide target section positioned on either side of the
vertical arm section (that holds the workpiece) in the second
direction are supported by the first guide rail and the second
guide rail. This makes it possible to stably transfer the workpiece
in a horizontal direction by suppressing occurrence of an
unnecessary moment, and suppressing the vertical motion of the
transfer jig as compared with the cantilever configuration
disclosed in Japanese Patent No. 3591721. Moreover, since the first
guide rail, the second guide rail, the first guide target section,
and the second guide target section (i.e., sliding sections) are
provided at a position offset from a position over the upper
opening of the surface treatment tank, it is possible to prevent a
situation in which dust or the like falls into the surface
treatment tank and contaminates the plating solution.
[0025] (2) According to another aspect of the invention, there is
provided a surface treatment system comprising:
[0026] a surface treatment tank that holds a treatment solution,
and has an upper opening;
[0027] a first guide rail and a second guide rail that extend along
a first direction that is parallel to a longitudinal direction of
the surface treatment tank at a position offset from a position
over the upper opening of the surface treatment tank;
[0028] a feed rail that extends along the first direction between
the first guide rail and the second guide rail at a position offset
from a position over the upper opening of the surface treatment
tank; and
[0029] a plurality of transfer jigs that respectively hold a
workpiece that is immersed in the treatment solution contained in
the surface treatment tank, and are supported by the first guide
rail and the second guide rail, the plurality of transfer jigs
coming in contact with the feed rail, and receiving current from
the feed rail,
[0030] each of the plurality of transfer jigs including:
[0031] a horizontal arm section that extends along a second
direction that intersects the first direction;
[0032] a first guide target section that is supported on one end of
the horizontal arm section, and is guided by the first guide
rail;
[0033] a second guide target section that is supported on another
end of the horizontal arm section, and is guided by the second
guide rail;
[0034] a vertical arm section that is suspended from the horizontal
arm section at a position between the first guide target section
and the second guide target section, and holds the workpiece;
and
[0035] a feed target section that is supported by the horizontal
arm section at a position between the guide target section and a
vertical arm section, and comes in contact with the feed rail.
[0036] According to this aspect of the invention, the surface
treatment system includes the feed rail in addition to the first
guide rail and the second guide rail, and the transfer jig further
includes the feed target section that comes in contact with the
feed rail. Since the feed rail is disposed between the first guide
rail and the second guide rail at a position offset from a position
over the upper opening of the surface treatment tank, the feed
target section of the transfer jig is provided at a position
between the first guide target section and the vertical arm
section. Therefore, the distance from the vertical arm section to
the first guide target section is longer than the distance from the
vertical arm section to the second guide target section. If the
second guide target section is not present, the length of the arm
that extends from the first guide target section to the vertical
arm section increases, so that an unnecessary moment that acts on
the transfer jig increases. Since the transfer jig has a doubly
supported beam configuration in which the first guide target
section and the second guide target section are supported by the
first guide rail and the second guide rail, an unnecessary moment
does not act on the transfer jig.
[0037] (3) According to another aspect of the invention, there is
provided a workpiece-holding jig that holds a sheet-like
rectangular workpiece in a solution contained in a treatment tank,
the workpiece-holding jig comprising:
[0038] a plurality of first chuck members that hold a first side of
the rectangular workpiece;
[0039] a plurality of second chuck members that hold a second side
of the rectangular workpiece, the second side being opposite to the
first the side in a first direction; and
[0040] a frame-like member that is disposed to surround the
rectangular workpiece, and supports the plurality of first chuck
members and the plurality of second chuck members, the frame-like
member including:
[0041] a first guide section that guides the plurality of first
chuck members so that the plurality of first chuck members are
movable along the first direction; and
[0042] a first biasing member that biases the plurality of first
chuck members in one direction in which the plurality of first
chuck members move away from the plurality of second chuck members
along the first direction.
[0043] The workpiece-holding jig is configured so that at least the
plurality of first chuck members among the plurality of first chuck
members and the second chuck members that hold the opposing sides
of the rectangular workpiece are movable along the first direction.
Therefore, tension is always applied to the rectangular workpiece
so that the planarity of the workpiece can be maintained even if
the rectangular workpiece has a small thickness. This makes it
possible to surface-treat each side of the rectangular workpiece
with a uniform thickness. Moreover, since the planarity of the
workpiece can be maintained without warping even when the
rectangular workpiece is repeatedly immersed in and removed from
the treatment solution during the surface treatment, it is possible
to prevent a situation in which the liquid pressure applied would
cause warping. This makes it possible to prevent a situation in
which the workpiece is removed from the chucks, or damaged due to
liquid pressure.
[0044] (4) According to another aspect of the invention, there is
provided a surface treatment system comprising:
[0045] a surface treatment tank that holds a treatment solution,
and has an upper opening;
[0046] a guide rail and a feed rail that extend along a first
direction that is parallel to a longitudinal direction of the
surface treatment tank at a position offset from a position over
the upper opening of the surface treatment tank; and
[0047] a plurality of transfer jigs that respectively hold a
workpiece that is immersed in the treatment solution contained in
the surface treatment tank, and are supported by the guide rail,
the plurality of transfer jigs coming in contact with the feed
rail, and receiving current from the feed rail,
[0048] each of the plurality of transfer jigs including:
[0049] a horizontal arm section that extends along a second
direction that intersects the first direction;
[0050] a guide target section that is supported on one end of the
horizontal arm section, and is guided by the guide rail; and
[0051] a feed target section that is supported by the horizontal
arm section at a position between the guide target section and a
vertical arm section, and comes in contact with the feed rail,
[0052] the feed target section including:
[0053] a contact section that comes in contact with the feed
rail;
[0054] a parallel link mechanism that connects the horizontal arm
section and the contact section; and
[0055] a biasing member that rotationally biases the parallel link
mechanism to apply a contact pressure to the contact section.
[0056] According to this aspect of the invention, the feed rail is
provided in addition to the guide rail, and the feed target section
that receives current from the feed rail can be caused to always
come in contact with the feed rail at a moderate contact pressure
independently of the transfer state of the transfer jig.
[0057] (5) According to another aspect of the invention, there is
provided a workpiece-holding jig that vertically holds a sheet-like
rectangular workpiece in a solution contained in a treatment tank,
and sets the rectangular workpiece as a cathode, the
workpiece-holding jig comprising:
[0058] a frame-like member that is disposed to surround the
rectangular workpiece;
[0059] a plurality of conductive first chuck members that are
supported by the frame-like member, and hold an upper side of the
rectangular workpiece;
[0060] a plurality of conductive second chuck members that are
supported by the frame-like member in a state in which the
plurality of second chuck members are electrically insulated from
the plurality of first chuck members, and hold a lower side of the
rectangular workpiece;
[0061] a first current-carrying section that supplies current to
the plurality of first chuck members; and
[0062] a second current-carrying section that supplies current to
the plurality of second chuck members.
[0063] According to this aspect of the invention, the workpiece is
held in a vertical state by holding the upper side and the lower
side of the workpiece in order to prevent a situation in which it
is impossible to maintain the suspended state of the workpiece due
to liquid pressure particularly when subjecting a very thin
workpiece to surface treatment. When the frame-like member, the
first chuck members, and the second chuck members are electrically
connected, the resistance of the current-carrying path that reaches
the lower frame member that supports the second chuck members is
inevitably higher than the resistance of the current-carrying path
that reaches the upper frame member that supports the first chuck
members. When holding only the upper side (end) of the workpiece
using the holding jig, the current-carrying path is limited to the
upper frame member. Therefore, the flow of current from the anode
to the workpiece and the frame-like member via the treatment
solution (or the flow of current in the reverse direction) more
easily occurs on the upper side of the workpiece that is held by
the workpiece-holding jig, so that the in-plane current
distribution of the workpiece becomes non-uniform. The in-plane
uniformity of the current distribution of the workpiece affects the
surface treatment quality of the workpiece. According to this
aspect of the invention, the first chuck members and the second
chuck members are electrically insulated, and current is supplied
to the first chuck members and the second chuck members through the
first current-carrying section and the second current-carrying
section, respectively. Therefore, the resistance and the current
value of the first current-carrying path from the first
current-carrying section to the first chuck members, and the
resistance and the current value of the second current-carrying
path from the second current-carrying section to the second chuck
members, can be set independently. This makes it possible to
improve the in-plane uniformity of the current distribution of the
workpiece, and further improve the surface treatment quality of the
workpiece.
[0064] (6) In the workpiece-holding jig as defined in (5),
[0065] the frame-like member may include:
[0066] a conductive upper frame member that supports the plurality
of first chuck members;
[0067] a conductive lower frame member that supports the plurality
of second chuck members;
[0068] two insulating members that are provided on either end of
the upper frame member; and
[0069] two conductive vertical frame members, an upper end of the
two vertical frame members being respectively supported by the two
insulating members, and a lower end of the two vertical frame
members being connected to either end of the lower frame
member,
[0070] the first current-carrying section may supply current to the
upper frame member, and
[0071] the second current-carrying section may supply current to
the two vertical frame members.
[0072] In this case, the first current-carrying section supplies
current to the first chuck members via the upper frame member, and
the second current-carrying section supplies current to the second
chuck members via the two vertical frame members and the lower
frame member. Since the upper frame member and the two vertical
frame members are electrically insulated by the two insulating
members, the resistance and the current value of each
current-carrying path can be set independently.
[0073] (7) The workpiece-holding jig as defined in (6) may further
comprise:
[0074] a common current-carrying section that supports the
frame-like member via part of the first current-carrying section,
and supplies current to the first current-carrying section and the
second current-carrying section.
[0075] According to the above configuration, the conductive member
provided as the transfer section among the functional sections
(transfer section and workpiece-holding section) of the
workpiece-holding jig can be used as the common current-carrying
section, and the common current-carrying section can be used as a
support section that supports the frame-like member, so that the
number of parts can be reduced.
[0076] (8) In the workpiece-holding jig as defined in (7),
[0077] the first current-carrying section may include:
[0078] an insulating section that is secured on the common
current-carrying section;
[0079] a conductive connection section that connects the insulating
section and the upper frame member; and
[0080] at least one upper frame current-carrying cable that
connects the common current-carrying section and the connection
section, and
[0081] the second current-carrying section may include a first
vertical frame current-carrying cable and a second vertical frame
current-carrying cable that connect the common current-carrying
section and the two vertical frame members.
[0082] According to the above configuration, since the first
current-carrying section includes the insulating section that is
secured on the common current-carrying section, and the conductive
connection section that connects the insulating section and the
upper frame member, the first current-carrying section can be used
as a support section that supports the frame-like member together
with the current-carrying section, so that the number of parts can
be reduced. The current-carrying paths from the common
current-carrying section can be separately provided using the at
least one upper frame current-carrying cable, the first vertical
frame current-carrying cable, and the second vertical frame
current-carrying cable.
[0083] (9) In the workpiece-holding jig as defined in (8),
[0084] the connection section may include:
[0085] a first vertical arm section and a second vertical arm
section that connect the insulating section and the upper frame
member;
[0086] a first protrusion section that protrudes from the first
vertical arm section; and
[0087] a second protrusion section that protrudes from the second
vertical arm section, and
[0088] the at least one upper frame current-carrying cable may
include a first upper frame current-carrying cable that connects
the common current-carrying section and the first protrusion
section, and a second upper frame current-carrying cable that
connects the common current-carrying section and the second
protrusion section.
[0089] When providing the first protrusion section and the second
protrusion section in addition to the first vertical arm section
and the second vertical arm section having a connection function,
the first protrusion section and the second protrusion section may
be allowed to function as a redundant section that increases the
current-carrying path of the first current-carrying section, or may
be formed of a material that differs from the material that forms
the first vertical arm section and the second vertical arm section.
More specifically, one of the first vertical frame current-carrying
cable and the second vertical frame current-carrying cable (i.e.,
second current-carrying section) and one of the two vertical frame
members form a current-carrying path between the common
current-carrying section and the lower frame member. Since the
vertical frame member is relatively long, and must be reduced in
cross-sectional area in order to reduce the weight, the vertical
frame member has a relatively high resistance. Therefore, the first
current-carrying section is provided with a relatively high
resistance using one of the first vertical arm section and the
second vertical arm section and one of the first protrusion section
and the second protrusion section so that a balance with the
relatively high resistance of the vertical frame member is
achieved. If a balance with the relatively high resistance of the
vertical frame member can be achieved, it is possible to use cables
that are identical in length and cross-sectional area of the
current-carrying section as the first upper frame current-carrying
cable, the second upper frame current-carrying cable, the first
vertical frame current-carrying cable, and the second vertical
frame current-carrying cable. This makes it possible to reduce the
frequency of erroneous installation.
[0090] (10) In the workpiece-holding jig as defined in any one of
(7) to (9), a resistance of a current path from the common
current-carrying section to the upper frame member and a resistance
of a current path from the common current-carrying section to the
lower frame member may be set to be substantially equal.
[0091] This makes it possible to improve the in-plane uniformity of
the current distribution of the workpiece, and further improve the
surface treatment quality of the workpiece.
[0092] (11) In the workpiece-holding jig as defined in any one of
(6) to (10), each of the two insulating members may include a guide
section that slidingly guides an upper end of either of the two
vertical frame member in a vertical direction. According to the
above configuration, the weight of the two vertical frame members,
the lower frame member, and the second chuck members is applied to
the lower end of the workpiece that is supported by the first chuck
members on the upper end, so that the workpiece can be held
(maintained) in a vertical state due to tension. Therefore,
deformation of the workpiece is prevented even if the liquid
pressure in the surface treatment tank is applied to the
workpiece.
[0093] (12) The workpiece-holding jig as defined in (11) may
further include a biasing member that biases either of the two
vertical frame member that is slidingly guided by the guide section
in a downward direction. According to the above configuration, the
biasing force of the biasing member is applied to the lower end of
the workpiece that is supported by the first chuck members on the
upper end in addition to the weight of the vertical frame members,
the lower frame member, and the second chuck members, so that the
workpiece can be held (maintained) in a vertical state due to
additional tension.
[0094] (13) In the workpiece-holding jig as defined in (12), a
lower end of the biasing member may be secured on either of the two
vertical frame members that is slidingly guided by the guide
section, an upper end of the biasing member may be secured on a
conductive stationary member that is supported by either of the two
insulating members, and either of the first and second vertical
frame current-carrying cables may be connected to the stationary
member. The first and second vertical frame current-carrying cables
thus supply current to the vertical frame member via the stationary
member and the biasing member. Alternatively, the first and second
vertical frame current-carrying cable may be connected directly to
the vertical frame member.
[0095] (14) According to another aspect of the invention, there is
provided a surface treatment system comprising:
[0096] a surface treatment tank that holds a treatment solution,
and has an upper opening;
[0097] the workpiece-holding jig as defined in any one of the above
(5) to (13) that holds a workpiece that is immersed in the
treatment solution contained in the surface treatment tank in a
suspended state, and sets the workpiece as a cathode; and
[0098] an anode that is disposed in the surface treatment tank at a
position opposite to the workpiece.
[0099] (15) According to another aspect of the invention, there is
provided a surface treatment system comprising:
[0100] a surface treatment tank that holds a treatment solution,
and has an upper opening;
[0101] a workpiece-holding jig that holds a workpiece that is
immersed in the treatment solution contained in the surface
treatment tank in a suspended state, and sets the workpiece as a
cathode;
[0102] an anode that extends in the surface treatment tank in a
vertical direction, and is disposed at a position opposite to the
workpiece; and
[0103] a relay current-carrying section that supplies current to
the anode at a position lower than a liquid surface of the
treatment solution contained in the surface treatment tank.
[0104] According to this aspect of the invention, current supplied
from the relay current-carrying section flows through the anode in
the upward direction and the downward direction from the contact
position of the relay current-carrying section when flowing toward
the workpiece (i.e., cathode) through the treatment solution
contained in the surface treatment tank. Therefore, current flows
through the workpiece to implement an improved (uniform) current
distribution in the vertical direction.
[0105] (16) In the surface treatment system as defined in (15),
[0106] the workpiece-holding jig may include:
[0107] a frame-like member that is disposed to surround the
workpiece;
[0108] a plurality of conductive first chuck members that are
supported by the frame-like member, and hold an upper side of the
workpiece;
[0109] a plurality of conductive second chuck members that are
supported by the frame-like member in a state in which the
plurality of second chuck members are electrically insulated from
the plurality of first chuck members, and hold a lower side of the
workpiece;
[0110] a first current-carrying section that supplies current to
the plurality of first chuck members; and
[0111] a second current-carrying section that supplies current to
the plurality of second chuck members.
[0112] According to the above configuration, it is possible to
improve the in-plane uniformity of the current distribution of the
workpiece, and further improve the surface treatment quality of the
workpiece due to the effects achieved by (5) and (14).
BRIEF DESCRIPTION OF THE DRAWINGS
[0113] FIG. 1 is a vertical cross-sectional view illustrating a
surface treatment system according to one embodiment of the
invention;
[0114] FIG. 2 is a partial enlarged view of the surface treatment
system illustrated in FIG. 1;
[0115] FIG. 3 is a perspective view illustrating a transfer
jig;
[0116] FIG. 4 is a view illustrating two guide rails and a transfer
jig;
[0117] FIG. 5 is a plan view illustrating a transfer jig;
[0118] FIG. 6 is a front view illustrating a transfer jig;
[0119] FIG. 7 is a view illustrating an anode current control
system;
[0120] FIGS. 8A and 8B are views illustrating gradual current
decrease control when a workpiece exits from a plating tank unit,
and gradual current increase control when a workpiece enters a
plating tank unit;
[0121] FIG. 9 is a partial enlarged view illustrating a frame-like
member of a workpiece-holding jig;
[0122] FIG. 10 is a view illustrating a state in which a workpiece
is held by moving a movable plate downward;
[0123] FIG. 11 is a view illustrating a state in which tension is
applied to a workpiece by supporting the workpiece using a first
chuck member;
[0124] FIG. 12 is a view illustrating the details of a feed target
section;
[0125] FIG. 13 is a front view illustrating a current-carrying
section and a workpiece-holding section of a workpiece-holding jig
according to another embodiment of the invention;
[0126] FIG. 14 is a side view illustrating the workpiece-holding
jig illustrated in FIG. 13;
[0127] FIG. 15 is a view illustrating an insulating member that
guides a vertical frame member, and a biasing member that biases
the vertical frame member;
[0128] FIG. 16 is a schematic view illustrating an anode that is
disposed in a treatment tank illustrated in FIG. 1;
[0129] FIG. 17 is a view schematically illustrating the
current-carrying section and the workpiece-holding section of the
workpiece-holding jig illustrated in FIG. 13;
[0130] FIG. 18 is a view schematically illustrating a method that
measures the current distribution of a workpiece;
[0131] FIG. 19 is a view illustrating contact points of a workpiece
and an anode; and
[0132] FIGS. 20A and 20B are views illustrating the current
distribution of a workpiece held by the workpiece-holding jig
illustrated in FIG. 6 and the current distribution of a workpiece
held by the workpiece-holding jig illustrated in FIG. 13.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0133] Exemplary embodiments of the invention are described in
detail below. Note that the following exemplary embodiments do not
in any way limit the scope of the invention defined by the claims
laid out herein. Note that all elements of the following exemplary
embodiments should not necessarily be taken as essential elements
of the invention.
1. Outline of Surface Treatment System
[0134] FIG. 1 is a vertical cross-sectional view illustrating a
surface treatment system (e.g., serial (continuous) plating
system). A serial plating system 10 illustrated in FIG. 1 is
configured so that a plurality of transfer jigs 30A that
respectively hold a workpiece 20 (e.g., circuit board) are
transferred (circulated) in the direction perpendicular to the
sheet. FIG. 1 illustrates two linear transfer paths 110 and 120
that form a circulating transfer path 100 and are parallel to each
other. The linear transfer paths 110 and 120 are connected at both
ends to form the loop-like circulating transfer path 100.
[0135] The circulating transfer path 100 is provided with a plating
tank (surface treatment tank in a broad sense) 200 in which the
workpiece 20 held by each transfer jig 30A is subjected to surface
treatment (e.g., plating), a mounting section (not illustrated in
FIG. 1) that is provided on the upstream side of the plating tank
200 in the circulating transfer path 100 and mounts the untreated
workpiece 20 on each transfer jig 30A, and a removal section (not
illustrated in FIG. 1) that is provided on the downstream side of
the plating tank 200 in the circulating transfer path 100 and
removes the treated workpiece 20 from each transfer jig 30A.
[0136] In one embodiment of the invention, the plating tank 200 is
provided along the second linear transfer path 120, and the
mounting section and the removal section are provided in the first
linear transfer path 110. The circulating transfer path 100 is also
provided with a pretreatment tank group 230 that is disposed on the
upstream side of the plating tank 200, and a post-treatment tank
group (not illustrated in FIG. 1) that is disposed on the
downstream side of the plating tank 200.
[0137] The pretreatment tank group 230 includes a degreasing tank,
a hot rinse tank, a rinse tank, a shower tank, an acid cleaning
tank, and the like that are sequentially disposed from the upstream
side between the mounting section and the plating tank 200. The
post-treatment tank group includes a shower tank and a rinse tank
that are sequentially disposed from the upstream side between the
plating tank 200 and the removal section. Note that the number and
the types of tanks included in the pretreatment tank group 230 and
the post-treatment tank group may be appropriately changed.
2. Transfer Jig and Two Guide Rails
[0138] As illustrated in FIG. 1, the serial plating system 10
includes the plating tank (surface treatment tank in a broad sense)
200 that holds a plating solution (treatment solution in a broad
sense) and has an upper opening 201. As illustrated in FIG. 2
(enlarged view), the serial plating system 10 also includes a first
guide rail 130 and a second guide rail 140 that extend along a
first direction (i.e., the direction perpendicular to the sheet)
that is parallel to the longitudinal direction of the plating tank
200 at a position offset from a position over the upper opening 201
of the plating tank 200. A plurality of transfer jigs 30A
respectively hold the workpiece 20 that is immersed in the
treatment solution contained in the plating tank 200, and are
supported by the first guide rail 130 and the second guide rail
140.
[0139] As illustrated in FIGS. 3 to 5, each transfer jig 30A
includes a horizontal arm section 300, a first guide target section
310, a second guide target section 320, and a vertical arm section
330. As illustrated in FIGS. 3 and 5, the horizontal arm section
300 includes a first horizontal arm 300A and a second horizontal
arm 300B that extend along a second direction B that
perpendicularly intersects (intersects in a broad sense) the first
direction (transfer direction) A, for example. As illustrated in
FIG. 4, the first guide target section 310 is supported on one end
of the horizontal arm section 300, and is guided by the first guide
rail 130. As illustrated in FIG. 4, the second guide target section
320 is supported on the other end of the horizontal arm section
300, and is guided by the second guide rail 140. As illustrated in
FIGS. 3 and 6, the vertical arm section 330 includes a first
vertical arm 330A and a second vertical arm 330B that are suspended
from a support plate 331 secured on the horizontal arm section 300,
and hold the workpiece 20 at a position between the first guide
target section 310 and the second guide target section 320.
[0140] Specifically, each transfer jig 30A has a doubly supported
beam configuration in which the first guide target section 310 and
the second guide target section 320 positioned on either side of
the vertical arm section 330 (that holds the workpiece 20) in the
second direction B are supported by the first guide rail 130 and
the second guide rail 140. Therefore, the workpiece 20 can be
stably held and transferred by suppressing the vertical motion of
the transfer jig 30A during transfer as compared with the
cantilever configuration disclosed in Japanese Patent No. 3591721.
Moreover, since the first guide rail 130, the second guide rail
140, the first guide target section 310, and the second guide
target section 320 (i.e., sliding sections) are provided at a
position offset from a position over the upper opening 201 of the
plating tank 200, it is possible to prevent a situation in which
dust or the like falls into the plating tank 200 and contaminates
the plating solution.
3. Transfer Jig, Two Guide Rails, and Feed Rail
[0141] The plating system 10 is configured so that the workpiece 20
is used as a cathode, and the plating tank 200 is provided with
cylindrical mesh bags (receiving sections) 202 and 203 that are
positioned on either side of the transfer path of the workpiece 20,
and respectively hold anodes (e.g., copper anode balls) 410R and
410L. An electric field is formed between the cathode and the anode
to electrolyze the plating solution and electroplate the workpiece
20. Therefore, it is necessary to supply current to the workpiece
20 during transfer. For example, at least one of the first guide
rail 130 and the second guide rail 140 may be used as a feed rail
in order to supply current to the workpiece 20. In this case, the
members of the transfer jig 30A that form a path that supplies
current to the workpiece 20 from the first guide rail 130 and the
second guide rail 140 may be formed of an electrical conductor.
[0142] In one embodiment of the invention, the plating system 10
includes a feed rail 210 in addition to the first guide rail 130
and the second guide rail 140 (see FIGS. 1 and 2). As illustrated
in FIG. 2, the feed rail 210 includes a plurality of (e.g., four)
split feed rails 210A to 210D that are insulated from each other in
order to implement the current control method disclosed in
JP-A-2009-132999. Each transfer jig 30A includes a feed target
section 340 that comes in contact with one of the split feed rails
210A to 210D and receives current (see FIGS. 2 to 5). The feed
target section 340 is disposed at a position between the first
guide target section 310 and the vertical arm section 330.
[0143] Specifically, each transfer jig 30A has a doubly supported
beam configuration in which the first guide target section 310 and
the second guide target section 320 positioned on either side of
the feed target section 340 in the second direction B are supported
by the first guide rail 130 and the second guide rail 140. This
makes it possible to stably maintain contact between the feed
target section 340 and the feed rail 210 when transferring the
transfer jig 30A by suppressing the vertical motion of the feed
target section 340.
4. Current Control Method that Utilizes Split Feed Rail
[0144] The current control method disclosed in JP-A-2009-132999 is
described below with reference to FIGS. 7, 8A, and 8B. Note that
the plating tank 200 illustrated in FIG. 1 has a length equal to or
more than about 10 m in the transfer direction perpendicular to the
sheet, for example. FIG. 7 illustrates a plating tank unit 200A.
The plating tank 200 illustrated in FIG. 1 is formed by connecting
a plurality of plating tank units 200A.
[0145] Power supply units 400A to 400D supply current to the
workpieces 20 during transfer through the corresponding split feed
rails 210A to 210D. The power supply units 400A to 400D can supply
current to the workpieces 20 having one side F1 and the other side
Fr via constant current control at a preset current value
(A/dm.sup.2). The power supply units 400A to 400D gradually
increase the amount of current when the workpiece 20 is transferred
to the plating tank unit 200A, and gradually decrease the amount of
current when the workpiece 20 is removed from the plating tank unit
200A.
[0146] The plating tank unit 200A illustrated in FIG. 7 can
simultaneously transfer N (e.g., three) workpieces 20 (20A to 20C
or 20B to 20D) in the transfer direction A in a completely immersed
state using the transfer jigs 30A (30A1 to 30A4). Note that the
term "completely immersed state" used herein refers to a state in
which at least the entirety of the plating target surface (side)
(i.e., the side F1 and the other side Fr illustrated in FIG. 10) of
the workpiece 20 is immersed in a plating solution Q contained in
the plating tank unit 200A (see FIGS. 1 and 2). Therefore, (N+1)
(i.e., four) workpieces 20 (20A to 20D) are immersed in the plating
solution Q contained in the plating tank unit 200A when the
workpiece 20A exits from an exit 200B of the plating tank unit
200A, and the workpiece 20D enters an inlet 200F of the plating
tank unit 200A.
[0147] In this case, the workpieces 20B and 20C are in the
completely immersed state, and the workpieces 20A and 20D are in a
partially immersed state. Note that the term "partially immersed
state" used herein refers to a state in which only part of the
plating target surface (side) (i.e., the side F1 and the other side
Fr illustrated in FIG. 10) of the workpieces 20A and 20D in the
lengthwise (longitudinal) direction is immersed in the plating
solution Q contained in the plating tank unit 200A. The area of the
workpiece positioned outside the plating tank unit 200A is disposed
in the adjacent plating tank unit 200A or another treatment
tank.
[0148] When the number of workpieces 20 that can be simultaneously
transferred in the plating tank unit 200A in the completely
immersed state is N (e.g., N=3), the number of split feed rails 210
and the number of power supply units 400 are (N+1) (=4).
[0149] As illustrated in FIG. 7, the left and right anodes (copper
anode balls) 410L and 410R that extend in the first direction A and
are opposite to each other are disposed in the plating tank unit
200A (plating solution Q). The anodes 410L and 410R are common to
each workpiece 20 (20A to 20D) held by each transfer jig 30A (30A1
to 30A4). The interval (electrode-electrode distance) between the
anodes 410L and 410R and each workpiece 20 during transfer is
maintained at a constant value (given value).
[0150] The power supply units 400A to 400D can change the current
value corresponding to each workpiece 20 held by the transfer jig
30A, and can perform constant current control at a preset current
value Is (A/dm.sup.2).
[0151] More specifically, the power supply units 400A to 400D are
configured to perform constant current control in a period in which
the workpiece 20 is transferred within the plating tank unit 200A
in the completely immersed state, gradually increase the amount of
current when the workpiece 20A enters the plating tank unit 200A in
the partially immersed state, and gradually decrease the amount of
current when the workpiece 20D exits from the plating tank unit
200A in the partially immersed state. The workpiece 20 that is in
the partially immersed state in two adjacent plating tank units
200A is subjected to gradual current decrease control in the
downstream-side plating tank unit 200A, and is subjected to gradual
current increase control in the upstream-side plating tank unit
200A.
[0152] As illustrated in FIG. 8A, the amount of current (Iin) is
gradually increased in proportion to the time (treatment area) when
the workpiece 20 enters the plating tank unit 200A in the partially
immersed state (period T12 (=t1 to t2)) until a preset current
value Is is reached. The workpiece 20 is subjected to constant
current control at the preset current value Is when the workpiece
20 has been completely immersed (t2). The workpiece 20 is subjected
to gradual current decrease control instead of constant current
control at the preset current value Is when the workpiece 20 exits
from the plating tank unit 200A in the partially immersed state
(period T34 (=t3 to t4) (see FIG. 8B). The amount of current (Idg)
is gradually decreased in inverse proportion to the time (treatment
area).
[0153] According to the above configuration, since the serial
plating process can be performed using the current value set
corresponding to each workpiece 20, a uniform high-quality coating
having a uniform thickness corresponding to the current value can
be formed on each workpiece 20.
5. Details of Transfer Jig
5.1. Feed Target Section
[0154] The feed target section 340 provided to each transfer jig
30A used in one embodiment of the invention comes in contact with
one of the N split feed rails 210A to 210D. A plurality of transfer
jigs 30A illustrated in FIG. 7 include first to Nth transfer jigs
30A1 to 30A4 in which the feed target section 340 is attached to
the horizontal arm section 300 at a different position among N
positions in the second direction B. The first to Nth transfer jigs
30A1 to 30A4 respectively come in contact with an arbitrary split
feed rail among the N split feed rails 210A to 210D.
[0155] According to one embodiment of the invention, the transfer
jigs 30A are formed using common parts, and respectively come in
contact with an arbitrary split feed rail among the split feed
rails 210A to 210D. As illustrated in FIG. 3, each transfer jig 30A
(first to Nth transfer jigs 30A1 to 30A4) includes a support
section (e.g., support plate 350) that supports the feed target
section 340. The support plate 350 includes N (N=4) attachment
sections 351 to 354 (e.g., threaded holes) that are provided at a
different position in the second direction B.
[0156] The feed target section 340 of each transfer jig 30A (first
to Nth transfer jigs 30A1 to 30A4 illustrated in FIG. 7) includes a
contact section 341 that comes in contact with the feed rail 210
(split feed rails 210A to 210D). The contact section 341 is
attached to one (attachment section 351 in FIG. 3) of the N
attachment sections 351 to 354 using a thumb screw, for example.
The first to Nth transfer jigs 30A1 to 30A4 can be provided using
common parts by attaching the contact section 341 to one attachment
section selected from the N attachment sections 351 to 354.
[0157] FIG. 12 illustrates the details of the feed target section
340. The feed target section 340 includes a four-bar linkage
parallel link mechanism 342 that links the support plate 350 and
the contact section 341 using parallel links 342A and 342B, for
example. The links 342A and 342B are always biased in the clockwise
direction using torsion coil springs 343 (i.e., biasing members).
This makes it possible to cause the contact section 341 to come in
contact with the feed rail 210 at a moderate contact pressure.
[0158] The parallel links 342A and 342B are tilted so that the
upper fulcrum precedes the lower fulcrum. In other words, the
longitudinal direction of the links 342A and 342B intersects the
transfer direction A at an acute angle. Therefore, since the
contact section 341 is pulled by the transfer jig 30A, the contact
section 341 travels stably. For example, when the contact section
341 that is vertically guided by two vertical shafts is vertically
biased in the downward direction using two springs without using
the parallel link mechanism 342, the contact section 341 is tilted
if the pressing force due to the springs is unbalanced. In this
case, the corner of the contact section 341 comes in contact with
the feed rail 210, so that the contact section 341 abnormally wears
away. According to one embodiment of the invention, the contact
section 341 comes in contact with the feed rail 210 in a state in
which the contact section 341 is disposed horizontally due to the
parallel link mechanism 342. This makes it possible to prevent a
situation in which the contact section 341 is tilted so that the
corner of the contact section 341 comes in contact with the feed
rail 210. Therefore, abnormal wear and connection failure of the
contact section 341 are prevented, and the lifetime of the contact
section 341 (expendable) can be increased.
[0159] Note that the configuration of the feed target section 340
illustrated in FIG. 12 may be applied to a surface treatment system
that includes the feed rail 210 in addition to the guide rails 130
and 140. The surface treatment system may include only one guide
rail and only one feed rail. When using the guide rail as the feed
rail, the feed target section significantly wears away due to
excessive pressure applied to the feed target section, so that the
lifetime of the feed target section decreases. According to one
embodiment of the invention, the feed target section 340 can be
caused to come in contact with the feed rail 210 at a moderate
contact pressure independently of the travel of the transfer jig
30A. This makes it possible to increase the lifetime of the contact
section 341 even if the feed target section 340 is formed of brass
or the like.
5.2. First Guide Target Section and Second Guide Target Section
[0160] The first guide rail 130 that guides the first guide target
section 310 includes an upper side, a first side surface, and a
second side surface opposite to the first side surface in a cross
section perpendicular to the longitudinal direction. The first
guide rail 130 is formed in a rectangular shape, for example.
[0161] The first guide target section 310 that is guided by the
first guide rail 130 may include a first roller 311 that comes in
rolling contact with the upper side of the first guide rail 130, a
second roller 312 that comes in rolling contact with the first side
surface of the first guide rail 130, and a third roller 313 that
comes in rolling contact with the second side surface of the first
guide rail 130. The second guide target section 320 may include a
fourth roller 321 that comes in rolling contact with the upper side
of the second guide rail 140. The first roller 311 and the fourth
roller 321 respectively come in contact with the upper side of the
first guide rail 130 and the upper side of the second guide rail
140 on either side of the transfer jig 30A in the second direction
B, so that the transfer jig 30A can stably travel in a horizontal
state. Since the second roller 312 and the third roller 313 hold
the side surfaces of the first guide rail 130, it is possible to
prevent a situation in which the transfer jig 30A is displaced in
the second direction B.
5.3. Continuous Transfer Driver Section
[0162] A continuous transfer driver section 150 illustrated in FIG.
2 is provided corresponding to each section obtained by dividing
the first linear transfer path 120 (see FIG. 1). The continuous
transfer driver section 150 includes pushers 153A and 153B that
respectively have linear guides 152A and 152B that move along a
fixed guide plate 151. The pushers 153A and 153B are independently
moved by a motor (not illustrated in FIG. 2). The transfer jig 30A
is continuously and linearly driven by the pushers 153A and 153B
within one section. The pushers 153A and 153B respectively have a
specific drive region and a common drive region within one section.
More specifically, the pusher 153 presses the transfer jig 30A in
the upstream-side specific drive region. The pusher 153B succeeds
the pusher 153A when continuously transferring the transfer jig 30A
in the common drive region. The pusher 153A moves forward by a
given stroke in the specific drive region and the common drive
region, moves backward to the previous position, and transfers the
subsequent transfer jig 30A. The pusher 153B operates in the same
manner as the pusher 153A.
[0163] The pushers 153A and 153B respectively have nail members
154A and 154B that press a first press target section 360 of the
transfer jig 30A. The nail members 154A and 154B press the first
press target section 360 of the transfer jig 30A when the pushers
153A and 153B move forward. The nail members 154A and 154B can be
displaced so as not to hinder the forward movement of the first
press target section 360 when the pushers 153A and 153B move
backward. Note that the transfer jig 30A includes a second press
target section 362 that is used when the workpiece is not
continuously transferred in the plating tank 20.
5.4. Hook Section
[0164] As illustrated in FIGS. 1 to 5, each transfer jig 30A
includes hook sections 370 for suspending the transfer jig 30A. As
illustrated in FIG. 1, the serial plating system 10 further
includes a lift section 160 that engages the hook sections 370, and
moves the workpiece 20 held by the transfer jig 30A upward and
downward relative to the plating tank 200.
[0165] This makes it unnecessary to use a vertical rail when moving
the workpiece upward and downward outside the plating tank 200, and
makes it possible to reduce the driving force.
5.5. Vertical Arm Section and Workpiece-Holding Jig
[0166] As illustrated in FIGS. 3 and 6, the vertical arm section
330 includes the vertical arms 330A and 330B, for example. The
workpiece-holding jig 500 is suspended from the vertical arms 330A
and 330B.
[0167] The workpiece-holding jig 500 is suitably used to hold a
very thin workpiece 20 having a thickness of 100 micrometers or
less, and preferably 60 micrometers or less. In one embodiment of
the invention, the thickness of the workpiece 20 is 40 micrometers
(=0.04 mm), for example.
[0168] As illustrated in FIGS. 3 and 6, the workpiece-holding jig
500 includes a plurality of first chuck members 510 that hold a
first side (e.g., upper side) 20a of a rectangular workpiece 20, a
plurality of second chuck members 520 that hold a second side 20b
of the rectangular workpiece 20 opposite to the first side in a
third direction (vertical direction) C, and a frame-like member 530
that is disposed to surround the rectangular workpiece 20, and
supports the first chuck members 510 and the second chuck members
520.
[0169] As illustrated in FIGS. 9 to 11, the frame-like member 530
includes a guide section 540 that guides the first chuck members
510 so that the first chuck members 510 are movable in the third
direction C, and a coil spring 550 (i.e., biasing member) that
biases the first chuck members 510 in a direction C1 in which the
first chuck members 510 move away from the second chuck members 520
along the first direction.
[0170] As illustrated in FIGS. 10 and 11, the frame-like member 530
includes a stationary plate 531, and a movable plate 532 that is
disposed to overlap the stationary plate 531. The guide section 540
has a long hole 533 that is formed in one (e.g., movable plate 532)
of the stationary plate 531 and the movable plate 532, and extends
in the third direction C, and a shaft (e.g., bolt shaft 534) that
is formed on the other of the stationary plate 531 and the movable
plate 532, and is inserted into the long hole 533. The coil spring
550 presses (biases) the movable plate 532 in the direction C1
relative to the stationary plate 531.
[0171] A configuration common to the first chuck members 510 and
the second chuck members 520 is described below with reference to
FIGS. 10 and 11 taking the first chuck member 510 as an example.
The first chuck member 510 includes a stationary member 511 that
comes in contact with the first side F1 of the workpiece 20, and a
movable member 512 that is disposed at a position opposite to the
stationary member 511 so as to come in and out of contact with the
second side Fr of the workpiece 20, and is pressed against the
second side Fr. The movable member 512 may include a driven element
512A that is driven when the movable member 512 is not pressed
against the second side Fr, a pressed element 512B that is always
pressed toward the stationary member via a hinge 513 due to spring
pressure when the driven element 512A is not driven, and a pressing
element 512C that is formed in the shape of a thin plate at the
free end of the pressed element 512B.
[0172] When attaching the workpiece 20 to the workpiece-holding jig
500, the second side 20b of the workpiece 20 is held using the
second chuck members 520. When holding the first side 20a of the
workpiece 20 using the first chuck members 510, the movable plate
532 is moved downward to the position (state) illustrated in FIG.
10 against the biasing force of the coil spring 550. In this case,
the pressed element 512B is set to an open state (see FIG. 10) by
driving the driven element 512A of each first chuck member 510. The
driven element 512A is then released, so that the first side 20a of
the workpiece 20 is held by the first chuck members 510. The
downward pressing force applied to the movable plate 532 is then
canceled. As a result, the movable plate 532 moves upward due to
the biasing force of the coil spring 550, and applies tension to
the workpiece 20, so that the planarity of the workpiece 20 can be
maintained.
[0173] Note that tension may be applied to the workpiece 20 using
at least either the first chuck members 510 or the second chuck
members 520. Specifically, the second chuck members 520 may have
the above tension-applying structure.
[0174] The workpiece-holding jig 500 having the above structure may
be used for a batch process that simultaneously immerses a
plurality of workpiece-holding jigs 500 in the treatment solution.
In this case, the first chuck members 510 and the second chuck
members 520 may be disposed on the right side and the left side
instead of the upper side and the lower side.
5.6. Current-Carrying Section and Workpiece Holding Section
Illustrated in FIG. 3
[0175] As illustrated in FIG. 3, the current-carrying section of
the workpiece-holding jig 30A includes the conductive horizontal
arm section 300, the conductive support plate 331, and the
conductive vertical arm sections 330A and 330B (330). A
workpiece-holding section 500 is suspended from the vertical arms
330A and 330B.
[0176] As illustrated in FIG. 3, the workpiece-holding section 500
includes a plurality of conductive first chuck members 510 that
hold the upper side 20a of the rectangular workpiece 20, a
plurality of conductive second chuck members 520 that hold the
lower side 20b of the rectangular workpiece 20 opposite to the
upper side 20a in the vertical direction C, and a frame-like member
530 that is disposed to surround the rectangular workpiece 20, and
supports the first chuck members 510 and the second chuck members
520.
[0177] The frame-like member 530 includes a conductive upper frame
member 531 that supports a plurality of first chuck members 510, a
conductive lower frame member 532 that supports a plurality of
second chuck members 520, and two conductive vertical frame members
533 and 534 that connect either end of the upper frame member 531
and either end of the lower frame member 532.
[0178] The frame-like member 530 illustrated in FIG. 3 is thus
configured so that the upper frame member 531 and the lower frame
member 532 are electrically connected via the vertical frame
members 533 and 534. The vertical arm sections 332A and 332B that
function as a current-carrying section are electrically connected
to the lower frame member 532 via the upper frame member 531.
Therefore, the resistance of the current-carrying path that reaches
the lower frame member 532 is inevitably higher than the resistance
of the current-carrying path that reaches the upper frame member
531. Accordingly, the workpiece 20 has a current distribution with
poor in-plane uniformity in which the current valve increases as
the distance from the upper side 20a decreases, and decreases as
the distance from the lower side 20b decreases.
6. Modification of Workpiece-Holding Section of Workpiece-Holding
Jig
6.1. First Chuck Member, Second Chuck Member, First
Current-Carrying Section, and Second Current-Carrying Section
[0179] FIGS. 13 and 14 illustrate a workpiece-holding jig 30B
according to one embodiment of the invention. FIGS. 13 and 14
illustrate a workpiece-holding section 600 having a configuration
differing from that of the workpiece-holding jig 30A illustrated in
FIG. 3. Note that the transfer section 300 illustrated in FIG. 3
can be used in common to the workpiece-holding jig 30A illustrated
in FIG. 3 and the workpiece-holding jig 30B according to one
embodiment of the invention. The workpiece-holding jig 30B
illustrated in FIG. 13 differs from the workpiece-holding jig 30A
illustrated in FIG. 3 as to the structure of the workpiece-holding
section 600 including a current-carrying section 650.
[0180] The workpiece-holding section 600 illustrated in FIG. 13
includes a plurality of conductive first chuck members 610 that
hold the upper side 20a of the rectangular workpiece 20, a
plurality of conductive second chuck members 620 that hold the
lower side 20b of the rectangular workpiece 20, a frame-like member
630 that is disposed to surround the rectangular workpiece 20, and
supports the first chuck members 610 and the second chuck members
620, and the current-carrying section 650 that includes a first
current-carrying section 660 and a second current-carrying section
670.
[0181] The first chuck members 610 and the second chuck members 620
are electrically insulated. The first current-carrying section 660
supplies current to the first chuck members 610. The second
current-carrying section 670 supplies current to the second chuck
members 620.
[0182] When subjecting a very thin workpiece to surface treatment,
it may be difficult to maintain the suspended state of the
workpiece 20 due to liquid pressure when placing the workpiece 20
in the surface treatment tank 200 by moving the workpiece 20
downward, or when transferring the workpiece 20 in the surface
treatment tank 200 in the transfer direction A (see FIG. 3).
[0183] Since the workpiece-holding section 600 according to one
embodiment of the invention holds the upper side 20a and the lower
side 20b of the workpiece 20, it is possible to maintain the
workpiece 20 in a vertical state even if liquid pressure is
applied. The distance between the first chuck members 610 and the
second chuck members 620 may be fixed. Note that the second chuck
members 620 may be movable in the vertical direction, and may be
vertically biased in the downward direction using a biasing member
(described later).
[0184] The workpiece-holding section 600 according to one
embodiment of the invention can prevent deformation of a very thin
workpiece 20 having a thickness of 100 micrometers or less, and
preferably 60 micrometers or less. In one embodiment of the
invention, the thickness of the workpiece 20 is 40 micrometers
(=0.04 mm), for example. Since the workpiece-holding section 500
illustrated in FIG. 3 includes the first chuck members 510 and the
second chuck members 520, the workpiece-holding section 500 can
also prevent deformation of the workpiece 20.
[0185] However, when the frame-like member 530, the first chuck
members 510, and the second chuck members 520 are electrically
connected as described above (see FIG. 3), the resistance of the
current-carrying path that reaches the lower frame member 532 that
supports the second chuck members 520 is inevitably higher than the
resistance of the current-carrying path that reaches the upper
frame member 531 that supports the first chuck members 510. This is
because the current-carrying path that reaches the lower frame
member 532 passes through the current-carrying path that reaches
the upper frame member 531. When holding only the upper side (end)
of the workpiece using the holding jig (see JP-A-2009-132956), the
current-carrying path is limited to the upper frame member.
Therefore, the flow of current from the anode to the workpiece and
the frame-like member via the treatment solution (or the flow of
current in the reverse direction) more easily occurs on the upper
side of the workpiece that is held by the workpiece-holding jig, so
that the in-plane current distribution of the workpiece becomes
non-uniform. The in-plane uniformity of the current distribution of
the workpiece affects the surface treatment quality of the
workpiece.
[0186] The workpiece-holding section 600 according to one
embodiment of the invention is configured so that the first chuck
members 610 and the second chuck members 620 are electrically
insulated, and current is supplied to the first chuck members 610
and the second chuck members 620 through the first current-carrying
section 660 and the second current-carrying section 670,
respectively. Therefore, the resistance of the current-carrying
path from the first current-carrying section 660 to the first chuck
members 610 and the resistance of the current-carrying path from
the second current-carrying section 670 to the second chuck members
620 can be set independently. This makes it possible to improve the
in-plane uniformity of the current distribution of the workpiece
20, and further improve the surface treatment quality of the
workpiece 20.
6.2. Frame-Like Member and Current-Carrying Section
[0187] The frame-like member 630 of the workpiece-holding section
600 according to one embodiment of the invention may include a
conductive upper frame member 631 that supports the first chuck
members 610, a conductive lower frame member 632 that supports the
second chuck members 620, two insulating members 640A and 640B that
are provided on either end of the upper frame member 631, and two
conductive vertical frame members 633 and 634, the upper end of the
vertical frame members 633 and 634 being respectively supported by
the insulating members 640A and 640B, and the lower end of the
vertical frame members 633 and 634 being connected to either end of
the lower frame member 632.
[0188] In this case, the first current-carrying section 660
supplies current to the first chuck members 610 via the upper frame
member 631. The second current-carrying section 670 supplies
current to the second chuck members 620 via the vertical frame
members 633 and 634 and the lower frame member 632. Since the upper
frame member 631 and the vertical frame members 633 and 634 are
electrically insulated by the insulating members 640 and 640B, the
resistance of each current-carrying path can be set
independently.
[0189] The current-carrying section 650 may utilize horizontal arm
sections 301 (301A, 301B) of the transfer section 300 as a common
current-carrying section that supplies current to the upper frame
member 631 and the lower frame member 632. The first
current-carrying section 660 supplies current to the first chuck
members 610 from the common current-carrying section 301 (301A,
301B) via the upper frame member 631. The second current-carrying
section 670 supplies current to the second chuck members 620 from
the common current-carrying section 301 (301A, 301B) via the
vertical frame members 633 and 634 and the lower frame member
632.
[0190] The workpiece-holding jig 30A includes the transfer section
300 and the current-carrying section 330. The horizontal arm
section 301 (301A, 301B) provided as the conductive member 300 may
be used as the common current-carrying section. Moreover, since the
common current-carrying section 301 (301A, 301B) can be used as a
support section that supports the frame-like member, the number of
parts can be reduced.
[0191] In this case, the first current-carrying section 660 may
include an insulating section 661 that is secured on the common
current-carrying section 301 (301A, 301B), a conductive connection
section 662 that connects the insulating section 661 and the upper
frame member 631, and at least one upper frame current-carrying
cable 663 that connects the common current-carrying section 301
(301A, 301B) and the connection section. The second
current-carrying section 670 may include a first vertical frame
current-carrying cable 671A and a second vertical frame
current-carrying cable 671B that connect the common
current-carrying section 301 (301A, 301B) and the vertical frame
members 633 and 634, respectively.
[0192] According to the above configuration, the conductive member
provided as the transfer section 300 among the functional sections
(transfer section 300 and workpiece-holding section 600) of the
workpiece-holding jig 30B can be used as the common
current-carrying section 301 (301A, 301B), and the common
current-carrying section 301 (301A, 301B) can be used as a support
section that supports the frame-like member 630, so that the number
of parts can be reduced. Moreover, since the first current-carrying
section 660 includes the conductive connection section 662 that
connects the insulating section 661 secured on the common
current-carrying section 301 (301A, 301B) with the upper frame
member 631, the first current-carrying section 660 can also be used
as a support section that supports the frame-like member 630.
Therefore, the number of parts can be reduced. The current-carrying
paths from the common current-carrying section 301 (301A, 301B) can
be separately provided using at least one upper frame
current-carrying cable 663, the first vertical frame
current-carrying cable 671A, and the second vertical frame
current-carrying cable 671B.
[0193] The connection section 662 may include a first vertical arm
section 662A and a second vertical arm section 662B that connect
the insulating section 661 and the upper frame member 631, a first
protrusion section 664A that protrudes from the first vertical arm
section 662A, and a second protrusion section 664B that protrudes
from the second vertical arm section 662B. In this case, at least
one upper frame current-carrying cable 663 may include a first
upper frame current-carrying cable 663A that connects the
horizontal arm section 301A (one of the common current-carrying
sections) and the first protrusion section 664A, and a second upper
frame current-carrying cable 663B that connects the horizontal arm
section 301B (the other of the common current-carrying sections)
and the second protrusion section 664B.
[0194] When providing the first protrusion section 664A and the
second protrusion section 664B in addition to the first vertical
arm section 662A and the second vertical arm section 662B having a
connection function, the first protrusion section 664A and the
second protrusion section 664B function as a redundant section that
increases the current-carrying path of the first current-carrying
section 660. More specifically, one of the first vertical frame
current-carrying cable 671A and the second vertical frame
current-carrying cable 671B (i.e., second current-carrying section
670) and one of the vertical frame members 633 and 634 form a
current-carrying path between the common current-carrying section
301 and the lower frame member 632. Since the vertical frame member
632 is relatively long, and must be reduced in cross-sectional area
in order to reduce the weight, the vertical frame member 632 has a
relatively high resistance. Therefore, the first current-carrying
section 660 is provided with a relatively high resistance using one
of the first vertical arm section 662A and the second vertical arm
section 662B and one of the first protrusion section 664A and the
second protrusion section 664B so that a balance with the
relatively high resistance of the vertical frame member 632 is
achieved. If a balance with the relatively high resistance of the
vertical frame member 632 can be achieved, it is possible to use
cables that are identical in length and cross-sectional area of the
current-carrying section as the first upper frame current-carrying
cable 663A, the second upper frame current-carrying cable 663B, the
first vertical frame current-carrying cable 671A, and the second
vertical frame current-carrying cable 671B. This makes it possible
to reduce the frequency of erroneous installation.
[0195] The resistance of the current path from the common
current-carrying section 301 to the upper frame member 631 and the
resistance of the current path from the common current-carrying
section 301 to the lower frame member 632 can be made substantially
equal by utilizing the workpiece-holding section 600 and the
current-carrying section 650 having the above structure. This makes
it possible to improve the in-plane uniformity of the current
distribution of the workpiece 20, and further improve the surface
treatment quality of the workpiece 20.
6.3. Structure that Maintains Workpiece in Vertical State
[0196] As illustrated in FIG. 15, each of the insulating members
640A and 640B may include a guide section 642A that slidingly
guides an upper end 633A or 634A of the vertical frame member 633
or 634 in the vertical direction. According to the above
configuration, the weight of the vertical frame members 633 and
634, the lower frame member 632, and the second chuck members 620
is applied to the lower end of the workpiece 20 that is supported
by the first chuck members 610 on the upper end, so that the
workpiece 20 can be held (maintained) in a vertical state due to
tension. Therefore, deformation of the workpiece 20 can be
prevented even if liquid pressure is applied to the workpiece 20 in
the surface treatment tank.
[0197] Each of the insulating members 640A and 640B may include a
stationary section 641 that is secured on either end of the upper
frame member 631, and a tubular body 642 that is secured on the
stationary section 641, and a hole 642A may serve as the guide
section that slidingly guides the upper end 633A or 634A of the
vertical frame member 633 or 634 in the vertical direction. Note
that the stationary section 641 and the tubular body 642 may be
integrally formed. The stationary section 641 may include a
vertical element 641A that is secured on the upper frame member
631, and two horizontal elements 641B and 641C, for example. The
tubular body 642 may be secured on the vertical element 641A and
the horizontal element 641B right under the horizontal element
641B. A flange 633B or 634B provided on the upper end 633A or 634A
of the vertical frame member 633 or 634 comes in contact with the
horizontal element 641B (i.e., lower-limit stopper). A clearance 6
is formed between the flange 633B or 634B and the horizontal
element 641B during normal use in which the workpiece 20 is held.
The workpiece 20 is held in a vertical state due to the weight of
each member as long as the clearance 6 is formed.
[0198] As illustrated in FIG. 15, a biasing member (e.g.,
compression coil spring 643) that biases the vertical frame member
633 or 634 that is slidingly guided by the guide section 642A in a
downward direction D, may be further provided. According to the
above configuration, the biasing force of the biasing member 643 is
applied to the lower end of the workpiece 20 that is supported by
the first chuck members 610 on the upper end in addition to the
weight of the vertical frame members 633 and 634, the lower frame
member 632, and the second chuck members 620, so that the workpiece
20 can be held (maintained) in a vertical state due to additional
tension.
[0199] The lower end of the biasing member 634 may be secured on
the flange 633B (634B) of the vertical frame member 633 or 634 that
is slidingly guided by the guide section 642A, for example.
[0200] The upper end of the biasing member 643 is secured on a
conductive stationary member 644 that is supported by the
horizontal element 641C of the insulating member 640A (640B). The
vertical frame current-carrying cable 671A (671B) may be connected
to the stationary member 644.
[0201] The vertical frame current-carrying cable 671A (671B) thus
supplies current to the vertical frame member 633 (634) via the
stationary member 644 and the biasing member 643.
[0202] As illustrated in FIG. 15, the stationary member 644 may
include a bolt 644A, a nut 644B, and two metal washers 644C and
644D, for example. The vertical frame current-carrying cable 671A
(671B) is fastened and held between the head of the bolt 644A and
the washer 644C at a position above the horizontal element 641C.
The upper end of the compression coil spring 643 is fastened and
held between the nut 644B and the washer 644D at a position right
under the horizontal element 641C. The vertical frame
current-carrying cable 671A (671B) and the biasing member 643 are
thus secured and electrically connected.
[0203] Note that the vertical frame current-carrying cable 671A
(671B) may be connected directly to the vertical frame member 633
(634) without using the stationary member 644 and the biasing
member 643. For example, a liquid surface Q1 (see FIG. 16) of the
treatment solution Q is positioned between the upper side 20a of
the workpiece 20 and the upper frame member 631 (see FIG. 13). The
vertical frame current-carrying cable 671A (671B) may be connected
directly to the vertical frame member 633 (634) at a position above
the liquid surface Q1. In this case, the biasing member
(compression coil spring) 643 illustrated in FIGS. 13 to 15 may be
disposed between the horizontal element 641 and the flange 633B
(634B), and need not form a current-carrying path.
7. Anode that Improves in-Plane Uniformity of Current Distribution
of Workpiece
[0204] FIG. 16 schematically illustrates the anode (anode) 410R
(410L) that is disposed on either side of the transfer path of the
workpiece 20 (see FIG. 1). Current is supplied to the anode 410R
(410L) from an anode bar 400 that extends along the longitudinal
direction of the treatment tank 200. The anode 410R (410L) is
normally connected directly to the anode bar 400. In one embodiment
of the invention, however, the anode 410R (410L) is secured on the
anode bar 400 in a state in which an insulator 430 is interposed
between the anode bar 400 and the anode 410R (410L). A relay
current-carrying section 420 is suspended from the anode bar 400. A
contact member 420A at the lower end of the relay current-carrying
section 420 is provided at a position lower than the liquid surface
Q1 of the treatment solution Q contained in the treatment tank 200.
The contact member 420A is connected to the anode 410R (410L) at a
middle position in the vertical direction, and supplies current to
the anode 410R (410L), for example.
[0205] The contact member 420A is preferably connected to the anode
410R (410L) at a position in the vertical direction that halves the
vertical dimension of the workpiece 20 that is suspended from the
workpiece-holding jig 30B. When using a plurality of types of
workpiece 20 that differ in vertical dimension, the vertical
position of the contact member 420A may be adjusted by utilizing a
well-known drive mechanism as the relay current-carrying section
420. Note that the contact member 420A may come in contact with the
anode 410R (410L) over a given length in the direction
perpendicular to the sheet.
[0206] Current supplied from the contact member 420 flows through
the anode 410R (410L) in an upward direction E1 and a downward
direction E2 from the position of the contact member 420 when
flowing toward the workpiece 20 (i.e., cathode) through the
treatment solution contained in the treatment tank 200. Therefore,
current flows through the workpiece 20 to implement an improved
(uniform) current distribution in the vertical direction.
8. Evaluation of in-Plane Uniformity of Current Distribution
[0207] FIG. 17 schematically illustrates the current-carrying paths
of the workpiece-holding jig 30B illustrated in FIG. 13. In FIG.
17, cables that are identical in length and cross-sectional area of
the current-carrying section are used as the first upper frame
current-carrying cable 663A, the second upper frame
current-carrying cable 663B, the first vertical frame
current-carrying cable 671A, and the second vertical frame
current-carrying cable 671B. The resistance of the current-carrying
path (F1 to F2 in FIG. 17) formed by the first current-carrying
section 660 excluding the first upper frame current-carrying cable
663A and the second upper frame current-carrying cable 663B and the
resistance of the current-carrying path (F3 to F4 in FIG. 17)
formed by the second current-carrying section 670 excluding the
first vertical frame current-carrying cable 671A and the second
vertical frame current-carrying cable 671B are set to be
substantially equal to each other.
[0208] The in-plane current distribution of the workpiece 20 was
measured using the workpiece-holding jig 30B illustrated in FIG. 13
having the characteristics schematically illustrated in FIG. 17,
and the anode 410L (410R) that employs the current supply method
illustrated in FIG. 16. The measurement was performed using wires
700 illustrated in FIG. 18 that correspond to the liquid resistance
instead of the treatment tank 200 illustrated in FIG. 1. As
illustrated in FIG. 19, thirty-six contact points P provided in the
workpiece 20 and thirty-six contact points P provided in the anode
410 were respectively connected using the wires 700. The positive
terminal of a power supply 430 that includes a rectifier was
connected to the anode 410 at a middle position in the vertical
direction through the relay current-carrying section 420, and the
negative terminal of the power supply 430 was connected to the
common current-carrying sections 301A and 301B of the
workpiece-holding jig 30B illustrated in FIG. 13.
[0209] FIG. 20A illustrates the measurement data. FIG. 20B
illustrates the measurement data obtained when using a comparative
example in which the workpiece-holding jig 30A illustrated in FIG.
3 was used instead of the workpiece-holding jig 30B illustrated in
FIG. 13, and current was supplied to the anode 410 illustrated in
FIG. 16 directly from the anode bar 400. As is clear from the
comparison between FIGS. 20A and 20B, the in-plane uniformity of
the current distribution of the workpiece 20 was significantly
improved by combining the workpiece-holding jig 30B according to
one embodiment of the invention and the current supply method
illustrated in FIG. 16. In particular, while the current value was
large near the upper end of the workpiece 20 in FIG. 20B
(comparative example), a variation in the current distribution of
the workpiece 20 in the vertical direction was significantly
reduced in FIG. 20A.
[0210] Although only some embodiments of the invention have been
described in detail above, those skilled in the art will readily
appreciate that many modifications are possible in the embodiments
without materially departing from the novel teachings and
advantages of the invention. Accordingly, such modifications are
intended to be included within the scope of the invention. Any term
cited with a different term having a broader meaning or the same
meaning at least once in the specification and the drawings can be
replaced by the different term in any place in the specification
and the drawings. The invention also includes any combinations of
the embodiments and the modifications.
[0211] For example, the common current-carrying section 301 of the
workpiece-holding jig 30B need not necessarily be used. A
current-carrying path from the current-carrying section 340 to the
first chuck members 610 and a current-carrying path from the
current-carrying section 340 to the second chuck members 620 may be
separately provided. In this case, independent power supplies may
be respectively connected to the two current-carrying paths.
[0212] Although only some embodiments of the invention have been
described in detail above, those skilled in the art will readily
appreciate that many modifications are possible in the embodiments
without materially departing from the novel teachings and
advantages of the invention. Accordingly, all such modifications
are intended to be included within scope of the invention.
[0213] Although the invention has been described using specific
terms, devices, and/or methods, such description is for
illustrative purposes of the preferred embodiment(s) only. Changes
may be made to the preferred embodiment(s) by those of ordinary
skill in the art without departing from the scope of the present
invention, which is set forth in the following claims. In addition,
it should be understood that aspects of the preferred embodiment(s)
generally may be interchanged in whole or in part.
* * * * *